Adding upstream version 2.4.57.upstream/2.4.57upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 5431 insertions, 0 deletions

diff --git a/modules/mappers/mod_rewrite.c b/modules/mappers/mod_rewrite.c
new file mode 100644
index 0000000..f93f23f
--- /dev/null
+++ b/modules/mappers/mod_rewrite.c
@@ -0,0 +1,5431 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*                       _                            _ _
+ *   _ __ ___   ___   __| |    _ __ _____      ___ __(_) |_ ___
+ *  | '_ ` _ \ / _ \ / _` |   | '__/ _ \ \ /\ / / '__| | __/ _ \
+ *  | | | | | | (_) | (_| |   | | |  __/\ V  V /| |  | | ||  __/
+ *  |_| |_| |_|\___/ \__,_|___|_|  \___| \_/\_/ |_|  |_|\__\___|
+ *                       |_____|
+ *
+ *  URL Rewriting Module
+ *
+ *  This module uses a rule-based rewriting engine (based on a
+ *  regular-expression parser) to rewrite requested URLs on the fly.
+ *
+ *  It supports an unlimited number of additional rule conditions (which can
+ *  operate on a lot of variables, even on HTTP headers) for granular
+ *  matching and even external database lookups (either via plain text
+ *  tables, DBM hash files or even external processes) for advanced URL
+ *  substitution.
+ *
+ *  It operates on the full URLs (including the PATH_INFO part) both in
+ *  per-server context (httpd.conf) and per-dir context (.htaccess) and even
+ *  can generate QUERY_STRING parts on result.   The rewriting result finally
+ *  can lead to internal subprocessing, external request redirection or even
+ *  to internal proxy throughput.
+ *
+ *  This module was originally written in April 1996 and
+ *  gifted exclusively to the The Apache Software Foundation in July 1997 by
+ *
+ *      Ralf S. Engelschall
+ *      rse engelschall.com
+ *      www.engelschall.com
+ */
+
+#include "apr.h"
+#include "apr_strings.h"
+#include "apr_hash.h"
+#include "apr_user.h"
+#include "apr_lib.h"
+#include "apr_signal.h"
+#include "apr_global_mutex.h"
+#include "apr_dbm.h"
+#include "apr_dbd.h"
+
+#include "apr_version.h"
+#if !APR_VERSION_AT_LEAST(2,0,0)
+#include "apu_version.h"
+#endif
+
+#include "mod_dbd.h"
+
+#if APR_HAS_THREADS
+#include "apr_thread_mutex.h"
+#endif
+
+#define APR_WANT_MEMFUNC
+#define APR_WANT_STRFUNC
+#define APR_WANT_IOVEC
+#include "apr_want.h"
+
+/* XXX: Do we really need these headers? */
+#if APR_HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#if APR_HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#if APR_HAVE_STDARG_H
+#include <stdarg.h>
+#endif
+#if APR_HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+#if APR_HAVE_CTYPE_H
+#include <ctype.h>
+#endif
+#if APR_HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+
+#include "ap_config.h"
+#include "httpd.h"
+#include "http_config.h"
+#include "http_request.h"
+#include "http_core.h"
+#include "http_log.h"
+#include "http_protocol.h"
+#include "http_ssl.h"
+#include "http_vhost.h"
+#include "util_mutex.h"
+
+#include "mod_rewrite.h"
+#include "ap_expr.h"
+
+#include "test_char.h"
+
+static ap_dbd_t *(*dbd_acquire)(request_rec*) = NULL;
+static void (*dbd_prepare)(server_rec*, const char*, const char*) = NULL;
+static const char* really_last_key = "rewrite_really_last";
+
+/*
+ * in order to improve performance on running production systems, you
+ * may strip all rewritelog code entirely from mod_rewrite by using the
+ * -DREWRITELOG_DISABLED compiler option.
+ *
+ * DO NOT USE THIS OPTION FOR PUBLIC BINARY RELEASES. Otherwise YOU are
+ * responsible for answering all the mod_rewrite questions out there.
+ */
+/* If logging is limited to APLOG_DEBUG or lower, disable rewrite log, too */
+#ifdef  APLOG_MAX_LOGLEVEL
+#if     APLOG_MAX_LOGLEVEL < APLOG_TRACE1
+#ifndef REWRITELOG_DISABLED
+#define REWRITELOG_DISABLED
+#endif
+#endif
+#endif
+
+#ifndef REWRITELOG_DISABLED
+
+#define rewritelog(x) do_rewritelog x
+#define REWRITELOG_MODE  ( APR_UREAD | APR_UWRITE | APR_GREAD | APR_WREAD )
+#define REWRITELOG_FLAGS ( APR_WRITE | APR_APPEND | APR_CREATE )
+
+#else /* !REWRITELOG_DISABLED */
+
+#define rewritelog(x)
+
+#endif /* REWRITELOG_DISABLED */
+
+/* remembered mime-type for [T=...] */
+#define REWRITE_FORCED_MIMETYPE_NOTEVAR "rewrite-forced-mimetype"
+#define REWRITE_FORCED_HANDLER_NOTEVAR  "rewrite-forced-handler"
+
+#define ENVVAR_SCRIPT_URL "SCRIPT_URL"
+#define REDIRECT_ENVVAR_SCRIPT_URL "REDIRECT_" ENVVAR_SCRIPT_URL
+#define ENVVAR_SCRIPT_URI "SCRIPT_URI"
+
+#define CONDFLAG_NONE               (1<<0)
+#define CONDFLAG_NOCASE             (1<<1)
+#define CONDFLAG_NOTMATCH           (1<<2)
+#define CONDFLAG_ORNEXT             (1<<3)
+#define CONDFLAG_NOVARY             (1<<4)
+
+#define RULEFLAG_NONE               (1<<0)
+#define RULEFLAG_FORCEREDIRECT      (1<<1)
+#define RULEFLAG_LASTRULE           (1<<2)
+#define RULEFLAG_NEWROUND           (1<<3)
+#define RULEFLAG_CHAIN              (1<<4)
+#define RULEFLAG_IGNOREONSUBREQ     (1<<5)
+#define RULEFLAG_NOTMATCH           (1<<6)
+#define RULEFLAG_PROXY              (1<<7)
+#define RULEFLAG_PASSTHROUGH        (1<<8)
+#define RULEFLAG_QSAPPEND           (1<<9)
+#define RULEFLAG_NOCASE             (1<<10)
+#define RULEFLAG_NOESCAPE           (1<<11)
+#define RULEFLAG_NOSUB              (1<<12)
+#define RULEFLAG_STATUS             (1<<13)
+#define RULEFLAG_ESCAPEBACKREF      (1<<14)
+#define RULEFLAG_DISCARDPATHINFO    (1<<15)
+#define RULEFLAG_QSDISCARD          (1<<16)
+#define RULEFLAG_END                (1<<17)
+#define RULEFLAG_ESCAPENOPLUS       (1<<18)
+#define RULEFLAG_QSLAST             (1<<19)
+#define RULEFLAG_QSNONE             (1<<20) /* programattic only */
+#define RULEFLAG_ESCAPECTLS         (1<<21)
+
+/* return code of the rewrite rule
+ * the result may be escaped - or not
+ */
+#define ACTION_NORMAL               (1<<0)
+#define ACTION_NOESCAPE             (1<<1)
+#define ACTION_STATUS               (1<<2)
+
+
+#define MAPTYPE_TXT                 (1<<0)
+#define MAPTYPE_DBM                 (1<<1)
+#define MAPTYPE_PRG                 (1<<2)
+#define MAPTYPE_INT                 (1<<3)
+#define MAPTYPE_RND                 (1<<4)
+#define MAPTYPE_DBD                 (1<<5)
+#define MAPTYPE_DBD_CACHE           (1<<6)
+
+#define ENGINE_DISABLED             (1<<0)
+#define ENGINE_ENABLED              (1<<1)
+
+#define OPTION_NONE                 (1<<0)
+#define OPTION_INHERIT              (1<<1)
+#define OPTION_INHERIT_BEFORE       (1<<2)
+#define OPTION_NOSLASH              (1<<3)
+#define OPTION_ANYURI               (1<<4)
+#define OPTION_MERGEBASE            (1<<5)
+#define OPTION_INHERIT_DOWN         (1<<6)
+#define OPTION_INHERIT_DOWN_BEFORE  (1<<7)
+#define OPTION_IGNORE_INHERIT       (1<<8)
+#define OPTION_IGNORE_CONTEXT_INFO  (1<<9)
+#define OPTION_LEGACY_PREFIX_DOCROOT (1<<10)
+
+#ifndef RAND_MAX
+#define RAND_MAX 32767
+#endif
+
+/* max cookie size in rfc 2109 */
+/* XXX: not used at all. We should do a check somewhere and/or cut the cookie */
+#define MAX_COOKIE_LEN 4096
+
+/* max line length (incl.\n) in text rewrite maps */
+#ifndef REWRITE_MAX_TXT_MAP_LINE
+#define REWRITE_MAX_TXT_MAP_LINE 1024
+#endif
+
+/* buffer length for prg rewrite maps */
+#ifndef REWRITE_PRG_MAP_BUF
+#define REWRITE_PRG_MAP_BUF 1024
+#endif
+
+/* for better readbility */
+#define LEFT_CURLY  '{'
+#define RIGHT_CURLY '}'
+
+/*
+ * expansion result items on the stack to save some cycles
+ *
+ * (5 == about 2 variables like "foo%{var}bar%{var}baz")
+ */
+#define SMALL_EXPANSION 5
+
+/*
+ * check that a subrequest won't cause infinite recursion
+ *
+ * either not in a subrequest, or in a subrequest
+ * and URIs aren't NULL and sub/main URIs differ
+ */
+#define subreq_ok(r) (!r->main || \
+    (r->main->uri && r->uri && strcmp(r->main->uri, r->uri)))
+
+#ifndef REWRITE_MAX_ROUNDS
+#define REWRITE_MAX_ROUNDS 32000
+#endif
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |                 Types and Structures
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+typedef struct {
+    const char *datafile;          /* filename for map data files         */
+    const char *dbmtype;           /* dbm type for dbm map data files     */
+    const char *checkfile;         /* filename to check for map existence */
+    const char *cachename;         /* for cached maps (txt/rnd/dbm)       */
+    int   type;                    /* the type of the map                 */
+    apr_file_t *fpin;              /* in  file pointer for program maps   */
+    apr_file_t *fpout;             /* out file pointer for program maps   */
+    apr_file_t *fperr;             /* err file pointer for program maps   */
+    char *(*func)(request_rec *,   /* function pointer for internal maps  */
+                  char *);
+    char **argv;                   /* argv of the external rewrite map    */
+    const char *dbdq;              /* SQL SELECT statement for rewritemap */
+    const char *checkfile2;        /* filename to check for map existence
+                                      NULL if only one file               */
+    const char *user;              /* run RewriteMap program as this user */
+    const char *group;             /* run RewriteMap program as this group */
+} rewritemap_entry;
+
+/* special pattern types for RewriteCond */
+typedef enum {
+    CONDPAT_REGEX = 0,
+    CONDPAT_FILE_EXISTS,
+    CONDPAT_FILE_SIZE,
+    CONDPAT_FILE_LINK,
+    CONDPAT_FILE_DIR,
+    CONDPAT_FILE_XBIT,
+    CONDPAT_LU_URL,
+    CONDPAT_LU_FILE,
+    CONDPAT_STR_LT,
+    CONDPAT_STR_LE,
+    CONDPAT_STR_EQ,
+    CONDPAT_STR_GT,
+    CONDPAT_STR_GE,
+    CONDPAT_INT_LT,
+    CONDPAT_INT_LE,
+    CONDPAT_INT_EQ,
+    CONDPAT_INT_GT,
+    CONDPAT_INT_GE,
+    CONDPAT_AP_EXPR
+} pattern_type;
+
+typedef struct {
+    char           *input;   /* Input string of RewriteCond   */
+    char           *pattern; /* the RegExp pattern string     */
+    ap_regex_t     *regexp;  /* the precompiled regexp        */
+    ap_expr_info_t *expr;    /* the compiled ap_expr          */
+    int             flags;   /* Flags which control the match */
+    pattern_type    ptype;   /* pattern type                  */
+    int             pskip;   /* back-index to display pattern */
+} rewritecond_entry;
+
+/* single linked list for env vars and cookies */
+typedef struct data_item {
+    struct data_item *next;
+    char *data;
+} data_item;
+
+typedef struct {
+    apr_array_header_t *rewriteconds;/* the corresponding RewriteCond entries */
+    char      *pattern;              /* the RegExp pattern string             */
+    ap_regex_t *regexp;              /* the RegExp pattern compilation        */
+    char      *output;               /* the Substitution string               */
+    int        flags;                /* Flags which control the substitution  */
+    char      *forced_mimetype;      /* forced MIME type of substitution      */
+    char      *forced_handler;       /* forced content handler of subst.      */
+    int        forced_responsecode;  /* forced HTTP response status           */
+    data_item *env;                  /* added environment variables           */
+    data_item *cookie;               /* added cookies                         */
+    int        skip;                 /* number of next rules to skip          */
+    int        maxrounds;            /* limit on number of loops with N flag  */
+    const char *escapes;             /* specific backref escapes              */
+    const char *noescapes;           /* specific backref chars not to escape  */
+} rewriterule_entry;
+
+typedef struct {
+    int           state;              /* the RewriteEngine state            */
+    int           options;            /* the RewriteOption state            */
+    apr_hash_t         *rewritemaps;  /* the RewriteMap entries             */
+    apr_array_header_t *rewriteconds; /* the RewriteCond entries (temp.)    */
+    apr_array_header_t *rewriterules; /* the RewriteRule entries            */
+    server_rec   *server;             /* the corresponding server indicator */
+    unsigned int state_set:1;
+    unsigned int options_set:1;
+} rewrite_server_conf;
+
+typedef struct {
+    int           state;              /* the RewriteEngine state           */
+    int           options;            /* the RewriteOption state           */
+    apr_array_header_t *rewriteconds; /* the RewriteCond entries (temp.)   */
+    apr_array_header_t *rewriterules; /* the RewriteRule entries           */
+    char         *directory;          /* the directory where it applies    */
+    const char   *baseurl;            /* the base-URL  where it applies    */
+    unsigned int state_set:1;
+    unsigned int options_set:1;
+    unsigned int baseurl_set:1;
+} rewrite_perdir_conf;
+
+/* the (per-child) cache structures.
+ */
+typedef struct cache {
+    apr_pool_t         *pool;
+    apr_hash_t         *maps;
+#if APR_HAS_THREADS
+    apr_thread_mutex_t *lock;
+#endif
+} cache;
+
+/* cached maps contain an mtime for the whole map and live in a subpool
+ * of the cachep->pool. That makes it easy to forget them if necessary.
+ */
+typedef struct {
+    apr_time_t mtime;
+    apr_pool_t *pool;
+    apr_hash_t *entries;
+} cachedmap;
+
+/* the regex structure for the
+ * substitution of backreferences
+ */
+typedef struct backrefinfo {
+    const char *source;
+    ap_regmatch_t regmatch[AP_MAX_REG_MATCH];
+} backrefinfo;
+
+/* single linked list used for
+ * variable expansion
+ */
+typedef struct result_list {
+    struct result_list *next;
+    apr_size_t len;
+    const char *string;
+} result_list;
+
+/* context structure for variable lookup and expansion
+ */
+typedef struct {
+    request_rec *r;
+    const char  *uri;
+    const char  *vary_this;
+    const char  *vary;
+    char        *perdir;
+    backrefinfo briRR;
+    backrefinfo briRC;
+} rewrite_ctx;
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |                 static module data
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+/* the global module structure */
+module AP_MODULE_DECLARE_DATA rewrite_module;
+
+/* rewritemap int: handler function registry */
+static apr_hash_t *mapfunc_hash;
+
+/* the cache */
+static cache *cachep;
+
+/* whether proxy module is available or not */
+static int proxy_available;
+
+/* Locks/Mutexes */
+static int rewrite_lock_needed = 0;
+static apr_global_mutex_t *rewrite_mapr_lock_acquire = NULL;
+static const char *rewritemap_mutex_type = "rewrite-map";
+
+/* Optional functions imported from mod_ssl when loaded: */
+static char *escape_backref(apr_pool_t *p, const char *path,
+                            const char *escapeme, const char *noescapeme,
+                            int flags);
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |              rewriting logfile support
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+#ifndef REWRITELOG_DISABLED
+static void do_rewritelog(request_rec *r, int level, char *perdir,
+                          const char *fmt, ...)
+        __attribute__((format(printf,4,5)));
+
+static void do_rewritelog(request_rec *r, int level, char *perdir,
+                          const char *fmt, ...)
+{
+    char *logline, *text;
+    const char *rhost, *rname;
+    int redir;
+    request_rec *req;
+    va_list ap;
+
+    if (!APLOG_R_IS_LEVEL(r, APLOG_DEBUG + level))
+        return;
+
+    rhost = ap_get_useragent_host(r, REMOTE_NOLOOKUP, NULL);
+    rname = ap_get_remote_logname(r);
+
+    for (redir=0, req=r; req->prev; req = req->prev) {
+        ++redir;
+    }
+
+    va_start(ap, fmt);
+    text = apr_pvsprintf(r->pool, fmt, ap);
+    va_end(ap);
+
+    logline = apr_psprintf(r->pool, "%s %s %s [%s/sid#%pp][rid#%pp/%s%s%s] "
+                                    "%s%s%s%s",
+                           rhost ? rhost : "UNKNOWN-HOST",
+                           rname ? rname : "-",
+                           r->user ? (*r->user ? r->user : "\"\"") : "-",
+                           ap_get_server_name(r),
+                           (void *)(r->server),
+                           (void *)r,
+                           r->main ? "subreq" : "initial",
+                           redir ? "/redir#" : "",
+                           redir ? apr_itoa(r->pool, redir) : "",
+                           perdir ? "[perdir " : "",
+                           perdir ? perdir : "",
+                           perdir ? "] ": "",
+                           text);
+
+    AP_REWRITE_LOG((uintptr_t)r, level, r->main ? 0 : 1, (char *)ap_get_server_name(r), logline);
+
+    /* Intentional no APLOGNO */
+    ap_log_rerror(APLOG_MARK, APLOG_DEBUG + level, 0, r, "%s", logline);
+
+    return;
+}
+#endif /* !REWRITELOG_DISABLED */
+
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |                URI and path functions
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+/* return number of chars of the scheme (incl. '://')
+ * if the URI is absolute (includes a scheme etc.)
+ * otherwise 0.
+ * If supportqs is not NULL, we return a whether or not
+ * the scheme supports a query string or not.
+ *
+ * NOTE: If you add new schemes here, please have a
+ *       look at escape_absolute_uri and splitout_queryargs.
+ *       Not every scheme takes query strings and some schemes
+ *       may be handled in a special way.
+ *
+ * XXX: we may consider a scheme registry, perhaps with
+ *      appropriate escape callbacks to allow other modules
+ *      to extend mod_rewrite at runtime.
+ */
+static unsigned is_absolute_uri(char *uri, int *supportsqs)
+{
+    int dummy, *sqs;
+
+    sqs = (supportsqs ? supportsqs : &dummy);
+    *sqs = 0;
+    /* fast exit */
+    if (*uri == '/' || strlen(uri) <= 5) {
+        return 0;
+    }
+
+    switch (*uri++) {
+    case 'a':
+    case 'A':
+        if (!ap_cstr_casecmpn(uri, "jp://", 5)) {        /* ajp://    */
+          *sqs = 1;
+          return 6;
+        }
+        break;
+
+    case 'b':
+    case 'B':
+        if (!ap_cstr_casecmpn(uri, "alancer://", 10)) {   /* balancer:// */
+          *sqs = 1;
+          return 11;
+        }
+        break;
+
+    case 'f':
+    case 'F':
+        if (!ap_cstr_casecmpn(uri, "tp://", 5)) {        /* ftp://    */
+            return 6;
+        }
+        if (!ap_cstr_casecmpn(uri, "cgi://", 6)) {       /* fcgi://   */
+            *sqs = 1;
+            return 7;
+        }
+        break;
+
+    case 'g':
+    case 'G':
+        if (!ap_cstr_casecmpn(uri, "opher://", 8)) {     /* gopher:// */
+            return 9;
+        }
+        break;
+
+    case 'h':
+    case 'H':
+        if (!ap_cstr_casecmpn(uri, "ttp://", 6)) {       /* http://   */
+            *sqs = 1;
+            return 7;
+        }
+        else if (!ap_cstr_casecmpn(uri, "ttps://", 7)) { /* https://  */
+            *sqs = 1;
+            return 8;
+        }
+        else if (!ap_cstr_casecmpn(uri, "2://", 4)) {    /* h2://     */
+            *sqs = 1;
+            return 5;
+        }
+        else if (!ap_cstr_casecmpn(uri, "2c://", 5)) {   /* h2c://    */
+            *sqs = 1;
+            return 6;
+        }
+        break;
+
+    case 'l':
+    case 'L':
+        if (!ap_cstr_casecmpn(uri, "dap://", 6)) {       /* ldap://   */
+            return 7;
+        }
+        break;
+
+    case 'm':
+    case 'M':
+        if (!ap_cstr_casecmpn(uri, "ailto:", 6)) {       /* mailto:   */
+            *sqs = 1;
+            return 7;
+        }
+        break;
+
+    case 'n':
+    case 'N':
+        if (!ap_cstr_casecmpn(uri, "ews:", 4)) {         /* news:     */
+            return 5;
+        }
+        else if (!ap_cstr_casecmpn(uri, "ntp://", 6)) {  /* nntp://   */
+            return 7;
+        }
+        break;
+
+    case 's':
+    case 'S':
+        if (!ap_cstr_casecmpn(uri, "cgi://", 6)) {       /* scgi://   */
+            *sqs = 1;
+            return 7;
+        }
+        break;
+
+    case 'w':
+    case 'W':
+        if (!ap_cstr_casecmpn(uri, "s://", 4)) {        /* ws://     */
+            *sqs = 1;
+            return 5;
+        }
+        else if (!ap_cstr_casecmpn(uri, "ss://", 5)) {  /* wss://    */
+            *sqs = 1;
+            return 6;
+        }
+        break;
+
+    case 'u':
+    case 'U':
+        if (!ap_cstr_casecmpn(uri, "nix:", 4)) {        /* unix:     */
+            *sqs = 1;
+            return (uri[4] == '/' && uri[5] == '/') ? 7 : 5;
+        }
+    }
+
+    return 0;
+}
+
+static const char c2x_table[] = "0123456789abcdef";
+
+static APR_INLINE unsigned char *c2x(unsigned what, unsigned char prefix,
+                                     unsigned char *where)
+{
+#if APR_CHARSET_EBCDIC
+    what = apr_xlate_conv_byte(ap_hdrs_to_ascii, (unsigned char)what);
+#endif /*APR_CHARSET_EBCDIC*/
+    *where++ = prefix;
+    *where++ = c2x_table[what >> 4];
+    *where++ = c2x_table[what & 0xf];
+    return where;
+}
+
+/*
+ * Escapes a backreference in a similar way as php's urlencode does.
+ * Based on ap_os_escape_path in server/util.c
+ */
+static char *escape_backref(apr_pool_t *p, const char *path,
+                            const char *escapeme, const char *noescapeme,
+                            int flags)
+{
+    char *copy = apr_palloc(p, 3 * strlen(path) + 1);
+    const unsigned char *s = (const unsigned char *)path;
+    unsigned char *d = (unsigned char *)copy;
+    int noplus = (flags & RULEFLAG_ESCAPENOPLUS) != 0;
+    int ctls = (flags & RULEFLAG_ESCAPECTLS) != 0;
+    unsigned char c;
+
+    while ((c = *s)) {
+        if (((ctls ? !TEST_CHAR(c, T_VCHAR_OBSTEXT) : !escapeme)
+             || (escapeme && ap_strchr_c(escapeme, c)))
+            && (!noescapeme || !ap_strchr_c(noescapeme, c))) {
+            if (apr_isalnum(c) || c == '_') {
+                *d++ = c;
+            }
+            else if (c == ' ' && !noplus) {
+                *d++ = '+';
+            }
+            else {
+                d = c2x(c, '%', d);
+            }
+        }
+        else {
+            *d++ = c;
+        }
+        ++s;
+    }
+    *d = '\0';
+    return copy;
+}
+
+/*
+ * escape absolute uri, which may or may not be path oriented.
+ * So let's handle them differently.
+ */
+static char *escape_absolute_uri(apr_pool_t *p, char *uri, unsigned scheme)
+{
+    char *cp;
+
+    /* be safe.
+     * NULL should indicate elsewhere, that something's wrong
+     */
+    if (!scheme || strlen(uri) < scheme) {
+        return NULL;
+    }
+
+    cp = uri + scheme;
+
+    /* scheme with authority part? */
+    if (cp[-1] == '/') {
+        /* skip host part */
+        while (*cp && *cp != '/') {
+            ++cp;
+        }
+
+        /* nothing after the hostpart. ready! */
+        if (!*cp || !*++cp) {
+            return apr_pstrdup(p, uri);
+        }
+
+        /* remember the hostname stuff */
+        scheme = cp - uri;
+
+        /* special thing for ldap.
+         * The parts are separated by question marks. From RFC 2255:
+         *     ldapurl = scheme "://" [hostport] ["/"
+         *               [dn ["?" [attributes] ["?" [scope]
+         *               ["?" [filter] ["?" extensions]]]]]]
+         */
+        if (!ap_cstr_casecmpn(uri, "ldap", 4)) {
+            char *token[5];
+            int c = 0;
+
+            token[0] = cp = apr_pstrdup(p, cp);
+            while (*cp && c < 4) {
+                if (*cp == '?') {
+                    token[++c] = cp + 1;
+                    *cp = '\0';
+                }
+                ++cp;
+            }
+
+            return apr_pstrcat(p, apr_pstrndup(p, uri, scheme),
+                                          ap_escape_uri(p, token[0]),
+                               (c >= 1) ? "?" : NULL,
+                               (c >= 1) ? ap_escape_uri(p, token[1]) : NULL,
+                               (c >= 2) ? "?" : NULL,
+                               (c >= 2) ? ap_escape_uri(p, token[2]) : NULL,
+                               (c >= 3) ? "?" : NULL,
+                               (c >= 3) ? ap_escape_uri(p, token[3]) : NULL,
+                               (c >= 4) ? "?" : NULL,
+                               (c >= 4) ? ap_escape_uri(p, token[4]) : NULL,
+                               NULL);
+        }
+    }
+
+    /* Nothing special here. Apply normal escaping. */
+    return apr_pstrcat(p, apr_pstrndup(p, uri, scheme),
+                       ap_escape_uri(p, cp), NULL);
+}
+
+/*
+ * split out a QUERY_STRING part from
+ * the current URI string
+ */
+static void splitout_queryargs(request_rec *r, int flags)
+{
+    char *q;
+    int split, skip;
+    int qsappend = flags & RULEFLAG_QSAPPEND;
+    int qsdiscard = flags & RULEFLAG_QSDISCARD;
+    int qslast = flags & RULEFLAG_QSLAST;
+
+    if (flags & RULEFLAG_QSNONE) {
+        rewritelog((r, 2, NULL, "discarding query string, no parse from substitution"));
+        r->args = NULL;
+        return;
+    }
+
+    /* don't touch, unless it's a scheme for which a query string makes sense.
+     * See RFC 1738 and RFC 2368.
+     */
+    if ((skip = is_absolute_uri(r->filename, &split))
+        && !split) {
+        r->args = NULL; /* forget the query that's still flying around */
+        return;
+    }
+
+    if (qsdiscard) {
+        r->args = NULL; /* Discard query string */
+        rewritelog((r, 2, NULL, "discarding query string"));
+    }
+
+    q = qslast ? ap_strrchr(r->filename + skip, '?') : ap_strchr(r->filename + skip, '?');
+
+    if (q != NULL) {
+        char *olduri;
+        apr_size_t len;
+
+        olduri = apr_pstrdup(r->pool, r->filename);
+        *q++ = '\0';
+        if (qsappend) {
+            if (*q) {
+                r->args = apr_pstrcat(r->pool, q, "&" , r->args, NULL);
+            }
+        }
+        else {
+            r->args = apr_pstrdup(r->pool, q);
+        }
+
+        if (r->args) {
+           len = strlen(r->args);
+
+           if (!len) {
+               r->args = NULL;
+           }
+           else if (r->args[len-1] == '&') {
+               r->args[len-1] = '\0';
+           }
+        }
+
+        rewritelog((r, 3, NULL, "split uri=%s -> uri=%s, args=%s", olduri,
+                    r->filename, r->args ? r->args : "<none>"));
+    }
+}
+
+/*
+ * strip 'http[s]://ourhost/' from URI
+ */
+static void reduce_uri(request_rec *r)
+{
+    char *cp;
+    apr_size_t l;
+
+    cp = (char *)ap_http_scheme(r);
+    l  = strlen(cp);
+    if (   strlen(r->filename) > l+3
+        && ap_cstr_casecmpn(r->filename, cp, l) == 0
+        && r->filename[l]   == ':'
+        && r->filename[l+1] == '/'
+        && r->filename[l+2] == '/' ) {
+
+        unsigned short port;
+        char *portp, *host, *url, *scratch;
+
+        scratch = apr_pstrdup(r->pool, r->filename); /* our scratchpad */
+
+        /* cut the hostname and port out of the URI */
+        cp = host = scratch + l + 3;    /* 3 == strlen("://") */
+        while (*cp && *cp != '/' && *cp != ':') {
+            ++cp;
+        }
+
+        if (*cp == ':') {      /* additional port given */
+            *cp++ = '\0';
+            portp = cp;
+            while (*cp && *cp != '/') {
+                ++cp;
+            }
+            *cp = '\0';
+
+            port = atoi(portp);
+            url = r->filename + (cp - scratch);
+            if (!*url) {
+                url = "/";
+            }
+        }
+        else if (*cp == '/') { /* default port */
+            *cp = '\0';
+
+            port = ap_default_port(r);
+            url = r->filename + (cp - scratch);
+        }
+        else {
+            port = ap_default_port(r);
+            url = "/";
+        }
+
+        /* now check whether we could reduce it to a local path... */
+        if (ap_matches_request_vhost(r, host, port)) {
+            rewrite_server_conf *conf = 
+                ap_get_module_config(r->server->module_config, &rewrite_module);
+            rewritelog((r, 3, NULL, "reduce %s -> %s", r->filename, url));
+            r->filename = apr_pstrdup(r->pool, url);
+
+            /* remember that the uri was reduced */
+            if(!(conf->options & OPTION_LEGACY_PREFIX_DOCROOT)) {
+                apr_table_setn(r->notes, "mod_rewrite_uri_reduced", "true");
+            }
+        }
+    }
+
+    return;
+}
+
+/*
+ * add 'http[s]://ourhost[:ourport]/' to URI
+ * if URI is still not fully qualified
+ */
+static void fully_qualify_uri(request_rec *r)
+{
+    if (r->method_number == M_CONNECT) {
+        return;
+    }
+    else if (!is_absolute_uri(r->filename, NULL)) {
+        const char *thisserver;
+        char *thisport;
+        int port;
+
+        thisserver = ap_get_server_name_for_url(r);
+        port = ap_get_server_port(r);
+        thisport = ap_is_default_port(port, r)
+                   ? ""
+                   : apr_psprintf(r->pool, ":%u", port);
+
+        r->filename = apr_psprintf(r->pool, "%s://%s%s%s%s",
+                                   ap_http_scheme(r), thisserver, thisport,
+                                   (*r->filename == '/') ? "" : "/",
+                                   r->filename);
+    }
+
+    return;
+}
+
+/*
+ * stat() only the first segment of a path
+ */
+static int prefix_stat(const char *path, apr_pool_t *pool)
+{
+    const char *curpath = path;
+    const char *root;
+    const char *slash;
+    char *statpath;
+    apr_status_t rv;
+
+    rv = apr_filepath_root(&root, &curpath, APR_FILEPATH_TRUENAME, pool);
+
+    if (rv != APR_SUCCESS) {
+        return 0;
+    }
+
+    /* let's recognize slashes only, the mod_rewrite semantics are opaque
+     * enough.
+     */
+    if ((slash = ap_strchr_c(curpath, '/')) != NULL) {
+        rv = apr_filepath_merge(&statpath, root,
+                                apr_pstrndup(pool, curpath,
+                                             (apr_size_t)(slash - curpath)),
+                                APR_FILEPATH_NOTABOVEROOT |
+                                APR_FILEPATH_NOTRELATIVE, pool);
+    }
+    else {
+        rv = apr_filepath_merge(&statpath, root, curpath,
+                                APR_FILEPATH_NOTABOVEROOT |
+                                APR_FILEPATH_NOTRELATIVE, pool);
+    }
+
+    if (rv == APR_SUCCESS) {
+        apr_finfo_t sb;
+
+        if (apr_stat(&sb, statpath, APR_FINFO_MIN, pool) == APR_SUCCESS) {
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
+/*
+ * substitute the prefix path 'match' in 'input' with 'subst' (RewriteBase)
+ */
+static char *subst_prefix_path(request_rec *r, char *input, const char *match,
+                               const char *subst)
+{
+    apr_size_t len = strlen(match);
+
+    if (len && match[len - 1] == '/') {
+        --len;
+    }
+
+    if (!strncmp(input, match, len) && input[len++] == '/') {
+        apr_size_t slen, outlen;
+        char *output;
+
+        rewritelog((r, 5, NULL, "strip matching prefix: %s -> %s", input,
+                    input+len));
+
+        slen = strlen(subst);
+        if (slen && subst[slen - 1] != '/') {
+            ++slen;
+        }
+
+        outlen = strlen(input) + slen - len;
+        output = apr_palloc(r->pool, outlen + 1); /* don't forget the \0 */
+
+        memcpy(output, subst, slen);
+        if (slen && !output[slen-1]) {
+            output[slen-1] = '/';
+        }
+        memcpy(output+slen, input+len, outlen - slen);
+        output[outlen] = '\0';
+
+        rewritelog((r, 4, NULL, "add subst prefix: %s -> %s", input+len,
+                    output));
+
+        return output;
+    }
+
+    /* prefix didn't match */
+    return input;
+}
+
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |                    caching support
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+static void set_cache_value(const char *name, apr_time_t t, char *key,
+                            char *val)
+{
+    cachedmap *map;
+
+    if (cachep) {
+#if APR_HAS_THREADS
+        apr_thread_mutex_lock(cachep->lock);
+#endif
+        map = apr_hash_get(cachep->maps, name, APR_HASH_KEY_STRING);
+
+        if (!map) {
+            apr_pool_t *p;
+
+            if (apr_pool_create(&p, cachep->pool) != APR_SUCCESS) {
+#if APR_HAS_THREADS
+                apr_thread_mutex_unlock(cachep->lock);
+#endif
+                return;
+            }
+            apr_pool_tag(p, "rewrite_cachedmap");
+
+            map = apr_palloc(cachep->pool, sizeof(cachedmap));
+            map->pool = p;
+            map->entries = apr_hash_make(map->pool);
+            map->mtime = t;
+
+            apr_hash_set(cachep->maps, name, APR_HASH_KEY_STRING, map);
+        }
+        else if (map->mtime != t) {
+            apr_pool_clear(map->pool);
+            map->entries = apr_hash_make(map->pool);
+            map->mtime = t;
+        }
+
+        /* Now we should have a valid map->entries hash, where we
+         * can store our value.
+         *
+         * We need to copy the key and the value into OUR pool,
+         * so that we don't leave it during the r->pool cleanup.
+         */
+        apr_hash_set(map->entries,
+                     apr_pstrdup(map->pool, key), APR_HASH_KEY_STRING,
+                     apr_pstrdup(map->pool, val));
+
+#if APR_HAS_THREADS
+        apr_thread_mutex_unlock(cachep->lock);
+#endif
+    }
+
+    return;
+}
+
+static char *get_cache_value(const char *name, apr_time_t t, char *key,
+                             apr_pool_t *p)
+{
+    cachedmap *map;
+    char *val = NULL;
+
+    if (cachep) {
+#if APR_HAS_THREADS
+        apr_thread_mutex_lock(cachep->lock);
+#endif
+        map = apr_hash_get(cachep->maps, name, APR_HASH_KEY_STRING);
+
+        if (map) {
+            /* if this map is outdated, forget it. */
+            if (map->mtime != t) {
+                apr_pool_clear(map->pool);
+                map->entries = apr_hash_make(map->pool);
+                map->mtime = t;
+            }
+            else {
+                val = apr_hash_get(map->entries, key, APR_HASH_KEY_STRING);
+                if (val) {
+                    /* copy the cached value into the supplied pool,
+                     * where it belongs (r->pool usually)
+                     */
+                    val = apr_pstrdup(p, val);
+                }
+            }
+        }
+
+#if APR_HAS_THREADS
+        apr_thread_mutex_unlock(cachep->lock);
+#endif
+    }
+
+    return val;
+}
+
+static int init_cache(apr_pool_t *p)
+{
+    cachep = apr_palloc(p, sizeof(cache));
+    if (apr_pool_create(&cachep->pool, p) != APR_SUCCESS) {
+        cachep = NULL; /* turns off cache */
+        return 0;
+    }
+    apr_pool_tag(cachep->pool, "rewrite_cachep");
+
+    cachep->maps = apr_hash_make(cachep->pool);
+#if APR_HAS_THREADS
+    (void)apr_thread_mutex_create(&(cachep->lock), APR_THREAD_MUTEX_DEFAULT, p);
+#endif
+
+    return 1;
+}
+
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |                    Map Functions
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+/*
+ * General Note: key is already a fresh string, created (expanded) just
+ * for the purpose to be passed in here. So one can modify key itself.
+ */
+
+static char *rewrite_mapfunc_toupper(request_rec *r, char *key)
+{
+    ap_str_toupper(key);
+
+    return key;
+}
+
+static char *rewrite_mapfunc_tolower(request_rec *r, char *key)
+{
+    ap_str_tolower(key);
+
+    return key;
+}
+
+static char *rewrite_mapfunc_escape(request_rec *r, char *key)
+{
+    return ap_escape_uri(r->pool, key);
+}
+
+static char *rewrite_mapfunc_unescape(request_rec *r, char *key)
+{
+    ap_unescape_url(key);
+
+    return key;
+}
+
+static char *select_random_value_part(request_rec *r, char *value)
+{
+    char *p = value;
+    unsigned n = 1;
+
+    /* count number of distinct values */
+    while ((p = ap_strchr(p, '|')) != NULL) {
+        ++n;
+        ++p;
+    }
+
+    if (n > 1) {
+        n = ap_random_pick(1, n);
+
+        /* extract it from the whole string */
+        while (--n && (value = ap_strchr(value, '|')) != NULL) {
+            ++value;
+        }
+
+        if (value) { /* should not be NULL, but ... */
+            p = ap_strchr(value, '|');
+            if (p) {
+                *p = '\0';
+            }
+        }
+    }
+
+    return value;
+}
+
+/* child process code */
+static void rewrite_child_errfn(apr_pool_t *p, apr_status_t err,
+                                const char *desc)
+{
+    ap_log_error(APLOG_MARK, APLOG_ERR, err, NULL, APLOGNO(00653) "%s", desc);
+}
+
+static apr_status_t rewritemap_program_child(apr_pool_t *p,
+                                             const char *progname, char **argv,
+                                             const char *user, const char *group,
+                                             apr_file_t **fpout,
+                                             apr_file_t **fpin)
+{
+    apr_status_t rc;
+    apr_procattr_t *procattr;
+    apr_proc_t *procnew;
+
+    if (   APR_SUCCESS == (rc=apr_procattr_create(&procattr, p))
+        && APR_SUCCESS == (rc=apr_procattr_io_set(procattr, APR_FULL_BLOCK,
+                                                  APR_FULL_BLOCK, APR_NO_PIPE))
+        && APR_SUCCESS == (rc=apr_procattr_dir_set(procattr,
+                                             ap_make_dirstr_parent(p, argv[0])))
+        && (!user || APR_SUCCESS == (rc=apr_procattr_user_set(procattr, user, "")))
+        && (!group || APR_SUCCESS == (rc=apr_procattr_group_set(procattr, group)))
+        && APR_SUCCESS == (rc=apr_procattr_cmdtype_set(procattr, APR_PROGRAM))
+        && APR_SUCCESS == (rc=apr_procattr_child_errfn_set(procattr,
+                                                           rewrite_child_errfn))
+        && APR_SUCCESS == (rc=apr_procattr_error_check_set(procattr, 1))) {
+
+        procnew = apr_pcalloc(p, sizeof(*procnew));
+        rc = apr_proc_create(procnew, argv[0], (const char **)argv, NULL,
+                             procattr, p);
+
+        if (rc == APR_SUCCESS) {
+            apr_pool_note_subprocess(p, procnew, APR_KILL_AFTER_TIMEOUT);
+
+            if (fpin) {
+                (*fpin) = procnew->in;
+            }
+
+            if (fpout) {
+                (*fpout) = procnew->out;
+            }
+        }
+    }
+
+    return (rc);
+}
+
+static apr_status_t run_rewritemap_programs(server_rec *s, apr_pool_t *p)
+{
+    rewrite_server_conf *conf;
+    apr_hash_index_t *hi;
+    apr_status_t rc;
+
+    conf = ap_get_module_config(s->module_config, &rewrite_module);
+
+    /*  If the engine isn't turned on,
+     *  don't even try to do anything.
+     */
+    if (conf->state == ENGINE_DISABLED) {
+        return APR_SUCCESS;
+    }
+
+    for (hi = apr_hash_first(p, conf->rewritemaps); hi; hi = apr_hash_next(hi)){
+        apr_file_t *fpin = NULL;
+        apr_file_t *fpout = NULL;
+        rewritemap_entry *map;
+        void *val;
+
+        apr_hash_this(hi, NULL, NULL, &val);
+        map = val;
+
+        if (map->type != MAPTYPE_PRG) {
+            continue;
+        }
+        if (!(map->argv[0]) || !*(map->argv[0]) || map->fpin || map->fpout) {
+            continue;
+        }
+
+        rc = rewritemap_program_child(p, map->argv[0], map->argv,
+                                      map->user, map->group,
+                                      &fpout, &fpin);
+        if (rc != APR_SUCCESS || fpin == NULL || fpout == NULL) {
+            ap_log_error(APLOG_MARK, APLOG_ERR, rc, s, APLOGNO(00654)
+                         "mod_rewrite: could not start RewriteMap "
+                         "program %s", map->checkfile);
+            return rc;
+        }
+        map->fpin  = fpin;
+        map->fpout = fpout;
+    }
+
+    return APR_SUCCESS;
+}
+
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |                  Lookup functions
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+static char *lookup_map_txtfile(request_rec *r, const char *file, char *key)
+{
+    apr_file_t *fp = NULL;
+    char line[REWRITE_MAX_TXT_MAP_LINE + 1]; /* +1 for \0 */
+    char *value, *keylast;
+    apr_status_t rv;
+
+    if ((rv = apr_file_open(&fp, file, APR_READ|APR_BUFFERED, APR_OS_DEFAULT,
+                            r->pool)) != APR_SUCCESS)
+    {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(00655)
+                      "mod_rewrite: can't open text RewriteMap file %s", file);
+        return NULL;
+    }
+
+    keylast = key + strlen(key);
+    value = NULL;
+    while (apr_file_gets(line, sizeof(line), fp) == APR_SUCCESS) {
+        char *p, *c;
+
+        /* ignore comments and lines starting with whitespaces */
+        if (*line == '#' || apr_isspace(*line)) {
+            continue;
+        }
+
+        p = line;
+        c = key;
+        while (c < keylast && *p == *c && !apr_isspace(*p)) {
+            ++p;
+            ++c;
+        }
+
+        /* key doesn't match - ignore. */
+        if (c != keylast || !apr_isspace(*p)) {
+            continue;
+        }
+
+        /* jump to the value */
+        while (apr_isspace(*p)) {
+            ++p;
+        }
+
+        /* no value? ignore */
+        if (!*p) {
+            continue;
+        }
+
+        /* extract the value and return. */
+        c = p;
+        while (*p && !apr_isspace(*p)) {
+            ++p;
+        }
+        value = apr_pstrmemdup(r->pool, c, p - c);
+        break;
+    }
+    apr_file_close(fp);
+
+    return value;
+}
+
+static char *lookup_map_dbmfile(request_rec *r, const char *file,
+                                const char *dbmtype, char *key)
+{
+#if APU_MAJOR_VERSION > 1 || (APU_MAJOR_VERSION == 1 && APU_MINOR_VERSION >= 7)
+    const apr_dbm_driver_t *driver;
+    const apu_err_t *err;
+#endif
+    apr_dbm_t *dbmfp = NULL;
+    apr_datum_t dbmkey;
+    apr_datum_t dbmval;
+    char *value;
+    apr_status_t rv;
+
+#if APU_MAJOR_VERSION > 1 || (APU_MAJOR_VERSION == 1 && APU_MINOR_VERSION >= 7)
+    if ((rv = apr_dbm_get_driver(&driver, dbmtype, &err,
+            r->pool)) != APR_SUCCESS) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(10287)
+                "mod_rewrite: can't load DBM library '%s': %s",
+                     err->reason, err->msg);
+        return NULL;
+    }
+    if ((rv = apr_dbm_open2(&dbmfp, driver, file, APR_DBM_READONLY,
+                              APR_OS_DEFAULT, r->pool)) != APR_SUCCESS) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(00656)
+                      "mod_rewrite: can't open DBM RewriteMap %s", file);
+        return NULL;
+    }
+#else
+    if ((rv = apr_dbm_open_ex(&dbmfp, dbmtype, file, APR_DBM_READONLY,
+                              APR_OS_DEFAULT, r->pool)) != APR_SUCCESS)
+    {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(00656)
+                      "mod_rewrite: can't open DBM RewriteMap %s", file);
+        return NULL;
+    }
+#endif
+
+    dbmkey.dptr  = key;
+    dbmkey.dsize = strlen(key);
+
+    if (apr_dbm_fetch(dbmfp, dbmkey, &dbmval) == APR_SUCCESS && dbmval.dptr) {
+        value = apr_pstrmemdup(r->pool, dbmval.dptr, dbmval.dsize);
+    }
+    else {
+        value = NULL;
+    }
+
+    apr_dbm_close(dbmfp);
+
+    return value;
+}
+static char *lookup_map_dbd(request_rec *r, char *key, const char *label)
+{
+    apr_status_t rv;
+    apr_dbd_prepared_t *stmt;
+    const char *errmsg;
+    apr_dbd_results_t *res = NULL;
+    apr_dbd_row_t *row = NULL;
+    char *ret = NULL;
+    int n = 0;
+    ap_dbd_t *db = dbd_acquire(r);
+    
+    if (db == NULL) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02963)
+                      "rewritemap: No db handle available! "
+                      "Check your database access");
+        return NULL;
+   }
+
+    stmt = apr_hash_get(db->prepared, label, APR_HASH_KEY_STRING);
+
+    rv = apr_dbd_pvselect(db->driver, r->pool, db->handle, &res,
+                          stmt, 0, key, NULL);
+    if (rv != 0) {
+        errmsg = apr_dbd_error(db->driver, db->handle, rv);
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00657)
+                      "rewritemap: error %s querying for %s", errmsg, key);
+        return NULL;
+    }
+    while ((rv = apr_dbd_get_row(db->driver, r->pool, res, &row, -1)) == 0) {
+        ++n;
+        if (ret == NULL) {
+            ret = apr_pstrdup(r->pool,
+                              apr_dbd_get_entry(db->driver, row, 0));
+        }
+        else {
+            /* randomise crudely amongst multiple results */
+            if ((double)rand() < (double)RAND_MAX/(double)n) {
+                ret = apr_pstrdup(r->pool,
+                                  apr_dbd_get_entry(db->driver, row, 0));
+            }
+        }
+    }
+    if (rv != -1) {
+        errmsg = apr_dbd_error(db->driver, db->handle, rv);
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00658)
+                      "rewritemap: error %s looking up %s", errmsg, key);
+    }
+    switch (n) {
+    case 0:
+        return NULL;
+    case 1:
+        return ret;
+    default:
+        /* what's a fair rewritelog level for this? */
+        rewritelog((r, 3, NULL, "Multiple values found for %s", key));
+        return ret;
+    }
+}
+
+static char *lookup_map_program(request_rec *r, apr_file_t *fpin,
+                                apr_file_t *fpout, char *key)
+{
+    char *buf;
+    char c;
+    apr_size_t i, nbytes, combined_len = 0;
+    apr_status_t rv;
+    const char *eol = APR_EOL_STR;
+    apr_size_t eolc = 0;
+    int found_nl = 0;
+    result_list *buflist = NULL, *curbuf = NULL;
+
+#ifndef NO_WRITEV
+    struct iovec iova[2];
+    apr_size_t niov;
+#endif
+
+    /* when `RewriteEngine off' was used in the per-server
+     * context then the rewritemap-programs were not spawned.
+     * In this case using such a map (usually in per-dir context)
+     * is useless because it is not available.
+     *
+     * newlines in the key leave bytes in the pipe and cause
+     * bad things to happen (next map lookup will use the chars
+     * after the \n instead of the new key etc etc - in other words,
+     * the Rewritemap falls out of sync with the requests).
+     */
+    if (fpin == NULL || fpout == NULL || ap_strchr(key, '\n')) {
+        return NULL;
+    }
+
+    /* take the lock */
+    if (rewrite_mapr_lock_acquire) {
+        rv = apr_global_mutex_lock(rewrite_mapr_lock_acquire);
+        if (rv != APR_SUCCESS) {
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(00659)
+                          "apr_global_mutex_lock(rewrite_mapr_lock_acquire) "
+                          "failed");
+            return NULL; /* Maybe this should be fatal? */
+        }
+    }
+
+    /* write out the request key */
+#ifdef NO_WRITEV
+    nbytes = strlen(key);
+    /* XXX: error handling */
+    apr_file_write_full(fpin, key, nbytes, NULL);
+    nbytes = 1;
+    apr_file_write_full(fpin, "\n", nbytes, NULL);
+#else
+    iova[0].iov_base = key;
+    iova[0].iov_len = strlen(key);
+    iova[1].iov_base = "\n";
+    iova[1].iov_len = 1;
+
+    niov = 2;
+    /* XXX: error handling */
+    apr_file_writev_full(fpin, iova, niov, &nbytes);
+#endif
+
+    buf = apr_palloc(r->pool, REWRITE_PRG_MAP_BUF + 1);
+
+    /* read in the response value */
+    nbytes = 1;
+    apr_file_read(fpout, &c, &nbytes);
+    do {
+        i = 0;
+        while (nbytes == 1 && (i < REWRITE_PRG_MAP_BUF)) {
+            if (c == eol[eolc]) {
+                if (!eol[++eolc]) {
+                    /* remove eol from the buffer */
+                    --eolc;
+                    if (i < eolc) {
+                        curbuf->len -= eolc-i;
+                        i = 0;
+                    }
+                    else {
+                        i -= eolc;
+                    }
+                    ++found_nl;
+                    break;
+                }
+            }
+
+            /* only partial (invalid) eol sequence -> reset the counter */
+            else if (eolc) {
+                eolc = 0;
+            }
+
+            /* catch binary mode, e.g. on Win32 */
+            else if (c == '\n') {
+                ++found_nl;
+                break;
+            }
+
+            buf[i++] = c;
+            apr_file_read(fpout, &c, &nbytes);
+        }
+
+        /* well, if there wasn't a newline yet, we need to read further */
+        if (buflist || (nbytes == 1 && !found_nl)) {
+            if (!buflist) {
+                curbuf = buflist = apr_palloc(r->pool, sizeof(*buflist));
+            }
+            else if (i) {
+                curbuf->next = apr_palloc(r->pool, sizeof(*buflist));
+                curbuf = curbuf->next;
+
+            }
+            curbuf->next = NULL;
+
+            if (i) {
+                curbuf->string = buf;
+                curbuf->len = i;
+                combined_len += i;
+                buf = apr_palloc(r->pool, REWRITE_PRG_MAP_BUF);
+            }
+
+            if (nbytes == 1 && !found_nl) {
+                continue;
+            }
+        }
+
+        break;
+    } while (1);
+
+    /* concat the stuff */
+    if (buflist) {
+        char *p;
+
+        p = buf = apr_palloc(r->pool, combined_len + 1); /* \0 */
+        while (buflist) {
+            if (buflist->len) {
+                memcpy(p, buflist->string, buflist->len);
+                p += buflist->len;
+            }
+            buflist = buflist->next;
+        }
+        *p = '\0';
+        i = combined_len;
+    }
+    else {
+        buf[i] = '\0';
+    }
+
+    /* give the lock back */
+    if (rewrite_mapr_lock_acquire) {
+        rv = apr_global_mutex_unlock(rewrite_mapr_lock_acquire);
+        if (rv != APR_SUCCESS) {
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(00660)
+                          "apr_global_mutex_unlock(rewrite_mapr_lock_acquire) "
+                          "failed");
+            return NULL; /* Maybe this should be fatal? */
+        }
+    }
+
+    /* catch the "failed" case */
+    if (i == 4 && !strcasecmp(buf, "NULL")) {
+        return NULL;
+    }
+
+    return buf;
+}
+
+/*
+ * generic map lookup
+ */
+static char *lookup_map(request_rec *r, char *name, char *key)
+{
+    rewrite_server_conf *conf;
+    rewritemap_entry *s;
+    char *value;
+    apr_finfo_t st;
+    apr_status_t rv;
+
+    /* get map configuration */
+    conf = ap_get_module_config(r->server->module_config, &rewrite_module);
+    s = apr_hash_get(conf->rewritemaps, name, APR_HASH_KEY_STRING);
+
+    /* map doesn't exist */
+    if (!s) {
+        return NULL;
+    }
+
+    switch (s->type) {
+    /*
+     * Text file map (perhaps random)
+     */
+    case MAPTYPE_RND:
+    case MAPTYPE_TXT:
+        rv = apr_stat(&st, s->checkfile, APR_FINFO_MIN, r->pool);
+        if (rv != APR_SUCCESS) {
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(00661)
+                          "mod_rewrite: can't access text RewriteMap file %s",
+                          s->checkfile);
+            return NULL;
+        }
+
+        value = get_cache_value(s->cachename, st.mtime, key, r->pool);
+        if (!value) {
+            rewritelog((r, 6, NULL,
+                        "cache lookup FAILED, forcing new map lookup"));
+
+            value = lookup_map_txtfile(r, s->datafile, key);
+            if (!value) {
+                rewritelog((r, 5, NULL, "map lookup FAILED: map=%s[txt] key=%s",
+                            name, key));
+                set_cache_value(s->cachename, st.mtime, key, "");
+                return NULL;
+            }
+
+            rewritelog((r, 5, NULL,"map lookup OK: map=%s[txt] key=%s -> val=%s",
+                        name, key, value));
+            set_cache_value(s->cachename, st.mtime, key, value);
+        }
+        else {
+            rewritelog((r,5,NULL,"cache lookup OK: map=%s[txt] key=%s -> val=%s",
+                        name, key, value));
+        }
+
+        if (s->type == MAPTYPE_RND && *value) {
+            value = select_random_value_part(r, value);
+            rewritelog((r, 5, NULL, "randomly chosen the subvalue `%s'",value));
+        }
+
+        return *value ? value : NULL;
+
+    /*
+     * DBM file map
+     */
+    case MAPTYPE_DBM:
+        rv = apr_stat(&st, s->checkfile, APR_FINFO_MIN, r->pool);
+        if (rv != APR_SUCCESS) {
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(00662)
+                          "mod_rewrite: can't access DBM RewriteMap file %s",
+                          s->checkfile);
+        }
+        else if(s->checkfile2 != NULL) {
+            apr_finfo_t st2;
+
+            rv = apr_stat(&st2, s->checkfile2, APR_FINFO_MIN, r->pool);
+            if (rv != APR_SUCCESS) {
+                ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(00663)
+                              "mod_rewrite: can't access DBM RewriteMap "
+                              "file %s", s->checkfile2);
+            }
+            else if(st2.mtime > st.mtime) {
+                st.mtime = st2.mtime;
+            }
+        }
+        if(rv != APR_SUCCESS) {
+            return NULL;
+        }
+
+        value = get_cache_value(s->cachename, st.mtime, key, r->pool);
+        if (!value) {
+            rewritelog((r, 6, NULL,
+                        "cache lookup FAILED, forcing new map lookup"));
+
+            value = lookup_map_dbmfile(r, s->datafile, s->dbmtype, key);
+            if (!value) {
+                rewritelog((r, 5, NULL, "map lookup FAILED: map=%s[dbm] key=%s",
+                            name, key));
+                set_cache_value(s->cachename, st.mtime, key, "");
+                return NULL;
+            }
+
+            rewritelog((r, 5, NULL, "map lookup OK: map=%s[dbm] key=%s -> "
+                        "val=%s", name, key, value));
+
+            set_cache_value(s->cachename, st.mtime, key, value);
+            return value;
+        }
+
+        rewritelog((r, 5, NULL, "cache lookup OK: map=%s[dbm] key=%s -> val=%s",
+                    name, key, value));
+        return *value ? value : NULL;
+
+    /*
+     * SQL map without cache
+     */
+    case MAPTYPE_DBD:
+        value = lookup_map_dbd(r, key, s->dbdq);
+        if (!value) {
+            rewritelog((r, 5, NULL, "SQL map lookup FAILED: map %s key=%s",
+                        name, key));
+            return NULL;
+        }
+
+        rewritelog((r, 5, NULL, "SQL map lookup OK: map %s key=%s, val=%s",
+                   name, key, value));
+
+        return value;
+
+    /*
+     * SQL map with cache
+     */
+    case MAPTYPE_DBD_CACHE:
+        value = get_cache_value(s->cachename, 0, key, r->pool);
+        if (!value) {
+            rewritelog((r, 6, NULL,
+                        "cache lookup FAILED, forcing new map lookup"));
+
+            value = lookup_map_dbd(r, key, s->dbdq);
+            if (!value) {
+                rewritelog((r, 5, NULL, "SQL map lookup FAILED: map %s key=%s",
+                            name, key));
+                set_cache_value(s->cachename, 0, key, "");
+                return NULL;
+            }
+
+            rewritelog((r, 5, NULL, "SQL map lookup OK: map %s key=%s, val=%s",
+                        name, key, value));
+
+            set_cache_value(s->cachename, 0, key, value);
+            return value;
+        }
+
+        rewritelog((r, 5, NULL, "cache lookup OK: map=%s[SQL] key=%s, val=%s",
+                    name, key, value));
+        return *value ? value : NULL;
+
+    /*
+     * Program file map
+     */
+    case MAPTYPE_PRG:
+        value = lookup_map_program(r, s->fpin, s->fpout, key);
+        if (!value) {
+            rewritelog((r, 5,NULL,"map lookup FAILED: map=%s key=%s", name,
+                        key));
+            return NULL;
+        }
+
+        rewritelog((r, 5, NULL, "map lookup OK: map=%s key=%s -> val=%s",
+                    name, key, value));
+        return value;
+
+    /*
+     * Internal Map
+     */
+    case MAPTYPE_INT:
+        value = s->func(r, key);
+        if (!value) {
+            rewritelog((r, 5,NULL,"map lookup FAILED: map=%s key=%s", name,
+                        key));
+            return NULL;
+        }
+
+        rewritelog((r, 5, NULL, "map lookup OK: map=%s key=%s -> val=%s",
+                    name, key, value));
+        return value;
+    }
+
+    return NULL;
+}
+
+/*
+ * lookup a HTTP header and set VARY note
+ */
+static const char *lookup_header(const char *name, rewrite_ctx *ctx)
+{
+    const char *val = apr_table_get(ctx->r->headers_in, name);
+
+    /* Skip the 'Vary: Host' header combination
+     * as indicated in rfc7231 section-7.1.4
+     */
+    if (val && strcasecmp(name, "Host") != 0) {
+        ctx->vary_this = ctx->vary_this
+                         ? apr_pstrcat(ctx->r->pool, ctx->vary_this, ", ",
+                                       name, NULL)
+                         : apr_pstrdup(ctx->r->pool, name);
+    }
+
+    return val;
+}
+
+/*
+ * lookahead helper function
+ * Determine the correct URI path in perdir context
+ */
+static APR_INLINE const char *la_u(rewrite_ctx *ctx)
+{
+    rewrite_perdir_conf *conf;
+
+    if (*ctx->uri == '/') {
+        return ctx->uri;
+    }
+
+    conf = ap_get_module_config(ctx->r->per_dir_config, &rewrite_module);
+
+    return apr_pstrcat(ctx->r->pool, conf->baseurl
+                                     ? conf->baseurl : conf->directory,
+                       ctx->uri, NULL);
+}
+
+/*
+ * generic variable lookup
+ */
+static char *lookup_variable(char *var, rewrite_ctx *ctx)
+{
+    const char *result;
+    request_rec *r = ctx->r;
+    apr_size_t varlen = strlen(var);
+
+    /* fast exit */
+    if (varlen < 4) {
+        return "";
+    }
+
+    result = NULL;
+
+    /* fast tests for variable length variables (sic) first */
+    if (var[3] == ':') {
+        if (var[4] && !strncasecmp(var, "ENV", 3)) {
+            var += 4;
+            result = apr_table_get(r->notes, var);
+
+            if (!result) {
+                result = apr_table_get(r->subprocess_env, var);
+            }
+            if (!result) {
+                result = getenv(var);
+            }
+        }
+        else if (var[4] && !strncasecmp(var, "SSL", 3)) {
+            result = ap_ssl_var_lookup(r->pool, r->server, r->connection, r,
+                                        var + 4);
+        }
+    }
+    else if (var[4] == ':') {
+        if (var[5]) {
+            request_rec *rr;
+            const char *path;
+
+            if (!strncasecmp(var, "HTTP", 4)) {
+                result = lookup_header(var+5, ctx);
+            }
+            else if (!strncasecmp(var, "LA-U", 4)) {
+                if (ctx->uri && subreq_ok(r)) {
+                    path = ctx->perdir ? la_u(ctx) : ctx->uri;
+                    rr = ap_sub_req_lookup_uri(path, r, NULL);
+                    ctx->r = rr;
+                    result = apr_pstrdup(r->pool, lookup_variable(var+5, ctx));
+                    ctx->r = r;
+                    ap_destroy_sub_req(rr);
+
+                    rewritelog((r, 5, ctx->perdir, "lookahead: path=%s var=%s "
+                                "-> val=%s", path, var+5, result));
+
+                    return (char *)result;
+                }
+            }
+            else if (!strncasecmp(var, "LA-F", 4)) {
+                if (ctx->uri && subreq_ok(r)) {
+                    path = ctx->uri;
+                    if (ctx->perdir && *path == '/') {
+                        /* sigh, the user wants a file based subrequest, but
+                         * we can't do one, since we don't know what the file
+                         * path is! In this case behave like LA-U.
+                         */
+                        rr = ap_sub_req_lookup_uri(path, r, NULL);
+                    }
+                    else {
+                        if (ctx->perdir) {
+                            rewrite_perdir_conf *conf;
+
+                            conf = ap_get_module_config(r->per_dir_config,
+                                                        &rewrite_module);
+
+                            path = apr_pstrcat(r->pool, conf->directory, path,
+                                               NULL);
+                        }
+
+                        rr = ap_sub_req_lookup_file(path, r, NULL);
+                    }
+
+                    ctx->r = rr;
+                    result = apr_pstrdup(r->pool, lookup_variable(var+5, ctx));
+                    ctx->r = r;
+                    ap_destroy_sub_req(rr);
+
+                    rewritelog((r, 5, ctx->perdir, "lookahead: path=%s var=%s "
+                                "-> val=%s", path, var+5, result));
+
+                    return (char *)result;
+                }
+            }
+        }
+    }
+
+    /* well, do it the hard way */
+    else {
+        apr_time_exp_t tm;
+
+        /* can't do this above, because of the getenv call */
+        ap_str_toupper(var);
+
+        switch (varlen) {
+        case  4:
+            if (!strcmp(var, "TIME")) {
+                apr_time_exp_lt(&tm, apr_time_now());
+                result = apr_psprintf(r->pool, "%04d%02d%02d%02d%02d%02d",
+                                      tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
+                                      tm.tm_hour, tm.tm_min, tm.tm_sec);
+                rewritelog((r, 1, ctx->perdir, "RESULT='%s'", result));
+                return (char *)result;
+            }
+            else if (!strcmp(var, "IPV6")) {
+                int flag = FALSE;
+#if APR_HAVE_IPV6
+                apr_sockaddr_t *addr = r->useragent_addr;
+                flag = (addr->family == AF_INET6 &&
+                        !IN6_IS_ADDR_V4MAPPED((struct in6_addr *)addr->ipaddr_ptr));
+                rewritelog((r, 1, ctx->perdir, "IPV6='%s'", flag ? "on" : "off"));
+#else
+                rewritelog((r, 1, ctx->perdir, "IPV6='off' (IPv6 is not enabled)"));
+#endif
+                result = (flag ? "on" : "off");
+            }
+            break;
+
+        case  5:
+            if (!strcmp(var, "HTTPS")) {
+                int flag = ap_ssl_conn_is_ssl(r->connection);
+                return apr_pstrdup(r->pool, flag ? "on" : "off");
+            }
+            break;
+
+        case  8:
+            switch (var[6]) {
+            case 'A':
+                if (!strcmp(var, "TIME_DAY")) {
+                    apr_time_exp_lt(&tm, apr_time_now());
+                    return apr_psprintf(r->pool, "%02d", tm.tm_mday);
+                }
+                break;
+
+            case 'E':
+                if (!strcmp(var, "TIME_SEC")) {
+                    apr_time_exp_lt(&tm, apr_time_now());
+                    return apr_psprintf(r->pool, "%02d", tm.tm_sec);
+                }
+                break;
+
+            case 'I':
+                if (!strcmp(var, "TIME_MIN")) {
+                    apr_time_exp_lt(&tm, apr_time_now());
+                    return apr_psprintf(r->pool, "%02d", tm.tm_min);
+                }
+                break;
+
+            case 'O':
+                if (!strcmp(var, "TIME_MON")) {
+                    apr_time_exp_lt(&tm, apr_time_now());
+                    return apr_psprintf(r->pool, "%02d", tm.tm_mon+1);
+                }
+                break;
+            }
+            break;
+
+        case  9:
+            switch (var[7]) {
+            case 'A':
+                if (var[8] == 'Y' && !strcmp(var, "TIME_WDAY")) {
+                    apr_time_exp_lt(&tm, apr_time_now());
+                    return apr_psprintf(r->pool, "%d", tm.tm_wday);
+                }
+                else if (!strcmp(var, "TIME_YEAR")) {
+                    apr_time_exp_lt(&tm, apr_time_now());
+                    return apr_psprintf(r->pool, "%04d", tm.tm_year+1900);
+                }
+                break;
+
+            case 'E':
+                if (!strcmp(var, "IS_SUBREQ")) {
+                    result = (r->main ? "true" : "false");
+                }
+                break;
+
+            case 'F':
+                if (!strcmp(var, "PATH_INFO")) {
+                    result = r->path_info;
+                }
+                break;
+
+            case 'P':
+                if (!strcmp(var, "AUTH_TYPE")) {
+                    result = r->ap_auth_type;
+                }
+                break;
+
+            case 'S':
+                if (!strcmp(var, "HTTP_HOST")) {
+                    result = lookup_header("Host", ctx);
+                }
+                break;
+
+            case 'U':
+                if (!strcmp(var, "TIME_HOUR")) {
+                    apr_time_exp_lt(&tm, apr_time_now());
+                    return apr_psprintf(r->pool, "%02d", tm.tm_hour);
+                }
+                break;
+            }
+            break;
+
+        case 11:
+            switch (var[8]) {
+            case 'A':
+                if (!strcmp(var, "SERVER_NAME")) {
+                    result = ap_get_server_name_for_url(r);
+                }
+                break;
+
+            case 'D':
+                if (*var == 'R' && !strcmp(var, "REMOTE_ADDR")) {
+                    result = r->useragent_ip;
+                }
+                else if (!strcmp(var, "SERVER_ADDR")) {
+                    result = r->connection->local_ip;
+                }
+                break;
+
+            case 'E':
+                if (*var == 'H' && !strcmp(var, "HTTP_ACCEPT")) {
+                    result = lookup_header("Accept", ctx);
+                }
+                else if (!strcmp(var, "THE_REQUEST")) {
+                    result = r->the_request;
+                }
+                break;
+
+            case 'I':
+                if (!strcmp(var, "API_VERSION")) {
+                    return apr_psprintf(r->pool, "%d:%d",
+                                        MODULE_MAGIC_NUMBER_MAJOR,
+                                        MODULE_MAGIC_NUMBER_MINOR);
+                }
+                break;
+
+            case 'K':
+                if (!strcmp(var, "HTTP_COOKIE")) {
+                    result = lookup_header("Cookie", ctx);
+                }
+                break;
+
+            case 'O':
+                if (*var == 'S' && !strcmp(var, "SERVER_PORT")) {
+                    return apr_psprintf(r->pool, "%u", ap_get_server_port(r));
+                }
+                else if (var[7] == 'H' && !strcmp(var, "REMOTE_HOST")) {
+                    result = ap_get_remote_host(r->connection,r->per_dir_config,
+                                                REMOTE_NAME, NULL);
+                }
+                else if (!strcmp(var, "REMOTE_PORT")) {
+                    return apr_itoa(r->pool, r->useragent_addr->port);
+                }
+                break;
+
+            case 'S':
+                if (*var == 'R' && !strcmp(var, "REMOTE_USER")) {
+                    result = r->user;
+                }
+                else if (!strcmp(var, "SCRIPT_USER")) {
+                    result = "<unknown>";
+                    if (r->finfo.valid & APR_FINFO_USER) {
+                        apr_uid_name_get((char **)&result, r->finfo.user,
+                                         r->pool);
+                    }
+                }
+                break;
+
+            case 'U':
+                if (!strcmp(var, "REQUEST_URI")) {
+                    result = r->uri;
+                }
+                break;
+            }
+            break;
+
+        case 12:
+            switch (var[3]) {
+            case 'I':
+                if (!strcmp(var, "SCRIPT_GROUP")) {
+                    result = "<unknown>";
+                    if (r->finfo.valid & APR_FINFO_GROUP) {
+                        apr_gid_name_get((char **)&result, r->finfo.group,
+                                         r->pool);
+                    }
+                }
+                break;
+
+            case 'O':
+                if (!strcmp(var, "REMOTE_IDENT")) {
+                    result = ap_get_remote_logname(r);
+                }
+                break;
+
+            case 'P':
+                if (!strcmp(var, "HTTP_REFERER")) {
+                    result = lookup_header("Referer", ctx);
+                }
+                break;
+
+            case 'R':
+                if (!strcmp(var, "QUERY_STRING")) {
+                    result = r->args;
+                }
+                break;
+
+            case 'V':
+                if (!strcmp(var, "SERVER_ADMIN")) {
+                    result = r->server->server_admin;
+                }
+                break;
+            }
+            break;
+
+        case 13:
+            if (!strcmp(var, "DOCUMENT_ROOT")) {
+                result = ap_document_root(r);
+            }
+            break;
+
+        case 14:
+            if (*var == 'H' && !strcmp(var, "HTTP_FORWARDED")) {
+                result = lookup_header("Forwarded", ctx);
+            }
+            else if (*var == 'C' && !strcmp(var, "CONTEXT_PREFIX")) {
+                result = ap_context_prefix(r);
+            }
+            else if (var[8] == 'M' && !strcmp(var, "REQUEST_METHOD")) {
+                result = r->method;
+            }
+            else if (!strcmp(var, "REQUEST_SCHEME")) {
+                result = ap_http_scheme(r);
+            }
+            break;
+
+        case 15:
+            switch (var[7]) {
+            case 'E':
+                if (!strcmp(var, "HTTP_USER_AGENT")) {
+                    result = lookup_header("User-Agent", ctx);
+                }
+                break;
+
+            case 'F':
+                if (!strcmp(var, "SCRIPT_FILENAME")) {
+                    result = r->filename; /* same as request_filename (16) */
+                }
+                break;
+
+            case 'P':
+                if (!strcmp(var, "SERVER_PROTOCOL")) {
+                    result = r->protocol;
+                }
+                break;
+
+            case 'S':
+                if (!strcmp(var, "SERVER_SOFTWARE")) {
+                    result = ap_get_server_banner();
+                }
+                break;
+            }
+            break;
+
+        case 16:
+            if (*var == 'C' && !strcmp(var, "CONN_REMOTE_ADDR")) {
+                result = r->connection->client_ip;
+            }
+            else if (!strcmp(var, "REQUEST_FILENAME")) {
+                result = r->filename; /* same as script_filename (15) */
+            }
+            break;
+
+        case 21:
+            if (!strcmp(var, "HTTP_PROXY_CONNECTION")) {
+                result = lookup_header("Proxy-Connection", ctx);
+            }
+            else if (!strcmp(var, "CONTEXT_DOCUMENT_ROOT")) {
+                result = ap_context_document_root(r);
+            }
+            break;
+        }
+    }
+
+    return apr_pstrdup(r->pool, result ? result : "");
+}
+
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |                 Expansion functions
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+/*
+ * Bracketed expression handling
+ * s points after the opening bracket
+ */
+static APR_INLINE char *find_closing_curly(char *s)
+{
+    unsigned depth;
+
+    for (depth = 1; *s; ++s) {
+        if (*s == RIGHT_CURLY && --depth == 0) {
+            return s;
+        }
+        else if (*s == LEFT_CURLY) {
+            ++depth;
+        }
+    }
+
+    return NULL;
+}
+
+static APR_INLINE char *find_char_in_curlies(char *s, int c)
+{
+    unsigned depth;
+
+    for (depth = 1; *s; ++s) {
+        if (*s == c && depth == 1) {
+            return s;
+        }
+        else if (*s == RIGHT_CURLY && --depth == 0) {
+            return NULL;
+        }
+        else if (*s == LEFT_CURLY) {
+            ++depth;
+        }
+    }
+
+    return NULL;
+}
+
+/* perform all the expansions on the input string
+ * putting the result into a new string
+ *
+ * for security reasons this expansion must be performed in a
+ * single pass, otherwise an attacker can arrange for the result
+ * of an earlier expansion to include expansion specifiers that
+ * are interpreted by a later expansion, producing results that
+ * were not intended by the administrator.
+ */
+static char *do_expand(char *input, rewrite_ctx *ctx, rewriterule_entry *entry)
+{
+    result_list *result, *current;
+    result_list sresult[SMALL_EXPANSION];
+    unsigned spc = 0;
+    apr_size_t span, inputlen, outlen;
+    char *p, *c;
+    apr_pool_t *pool = ctx->r->pool;
+
+    span = strcspn(input, "\\$%");
+    inputlen = strlen(input);
+
+    /* fast exit */
+    if (inputlen == span) {
+        return apr_pstrmemdup(pool, input, inputlen);
+    }
+
+    /* well, actually something to do */
+    result = current = &(sresult[spc++]);
+
+    p = input + span;
+    current->next = NULL;
+    current->string = input;
+    current->len = span;
+    outlen = span;
+
+    /* loop for specials */
+    do {
+        /* prepare next entry */
+        if (current->len) {
+            current->next = (spc < SMALL_EXPANSION)
+                            ? &(sresult[spc++])
+                            : (result_list *)apr_palloc(pool,
+                                                        sizeof(result_list));
+            current = current->next;
+            current->next = NULL;
+            current->len = 0;
+        }
+
+        /* escaped character */
+        if (*p == '\\') {
+            current->len = 1;
+            ++outlen;
+            if (!p[1]) {
+                current->string = p;
+                break;
+            }
+            else {
+                current->string = ++p;
+                ++p;
+            }
+        }
+
+        /* variable or map lookup */
+        else if (p[1] == '{') {
+            char *endp;
+
+            endp = find_closing_curly(p+2);
+            if (!endp) {
+                current->len = 2;
+                current->string = p;
+                outlen += 2;
+                p += 2;
+            }
+
+            /* variable lookup */
+            else if (*p == '%') {
+                p = lookup_variable(apr_pstrmemdup(pool, p+2, endp-p-2), ctx);
+
+                span = strlen(p);
+                current->len = span;
+                current->string = p;
+                outlen += span;
+                p = endp + 1;
+            }
+
+            /* map lookup */
+            else {     /* *p == '$' */
+                char *key;
+
+                /*
+                 * To make rewrite maps useful, the lookup key and
+                 * default values must be expanded, so we make
+                 * recursive calls to do the work. For security
+                 * reasons we must never expand a string that includes
+                 * verbatim data from the network. The recursion here
+                 * isn't a problem because the result of expansion is
+                 * only passed to lookup_map() so it cannot be
+                 * re-expanded, only re-looked-up. Another way of
+                 * looking at it is that the recursion is entirely
+                 * driven by the syntax of the nested curly brackets.
+                 */
+
+                key = find_char_in_curlies(p+2, ':');
+                if (!key) {
+                    current->len = 2;
+                    current->string = p;
+                    outlen += 2;
+                    p += 2;
+                }
+                else {
+                    char *map, *dflt;
+
+                    map = apr_pstrmemdup(pool, p+2, endp-p-2);
+                    key = map + (key-p-2);
+                    *key++ = '\0';
+                    dflt = find_char_in_curlies(key, '|');
+                    if (dflt) {
+                        *dflt++ = '\0';
+                    }
+
+                    /* reuse of key variable as result */
+                    key = lookup_map(ctx->r, map, do_expand(key, ctx, entry));
+
+                    if (!key && dflt && *dflt) {
+                        key = do_expand(dflt, ctx, entry);
+                    }
+
+                    if (key) {
+                        span = strlen(key);
+                        current->len = span;
+                        current->string = key;
+                        outlen += span;
+                    }
+
+                    p = endp + 1;
+                }
+            }
+        }
+
+        /* backreference */
+        else if (apr_isdigit(p[1])) {
+            int n = p[1] - '0';
+            backrefinfo *bri = (*p == '$') ? &ctx->briRR : &ctx->briRC;
+
+            /* see ap_pregsub() in server/util.c */
+            if (bri->source && n < AP_MAX_REG_MATCH
+                && bri->regmatch[n].rm_eo > bri->regmatch[n].rm_so) {
+                span = bri->regmatch[n].rm_eo - bri->regmatch[n].rm_so;
+                if (entry && (entry->flags & RULEFLAG_ESCAPEBACKREF)) {
+                    /* escape the backreference */
+                    char *tmp2, *tmp;
+                    tmp = apr_pstrmemdup(pool, bri->source + bri->regmatch[n].rm_so, span);
+                    tmp2 = escape_backref(pool, tmp, entry->escapes, entry->noescapes,
+                                          entry->flags);
+                    rewritelog((ctx->r, 5, ctx->perdir, "escaping backreference '%s' to '%s'",
+                            tmp, tmp2));
+
+                    current->len = span = strlen(tmp2);
+                    current->string = tmp2;
+                } else {
+                    current->len = span;
+                    current->string = bri->source + bri->regmatch[n].rm_so;
+                }
+
+                outlen += span;
+            }
+
+            p += 2;
+        }
+
+        /* not for us, just copy it */
+        else {
+            current->len = 1;
+            current->string = p++;
+            ++outlen;
+        }
+
+        /* check the remainder */
+        if (*p && (span = strcspn(p, "\\$%")) > 0) {
+            if (current->len) {
+                current->next = (spc < SMALL_EXPANSION)
+                                ? &(sresult[spc++])
+                                : (result_list *)apr_palloc(pool,
+                                                           sizeof(result_list));
+                current = current->next;
+                current->next = NULL;
+            }
+
+            current->len = span;
+            current->string = p;
+            p += span;
+            outlen += span;
+        }
+
+    } while (p < input+inputlen);
+
+    /* assemble result */
+    c = p = apr_palloc(pool, outlen + 1); /* don't forget the \0 */
+    do {
+        if (result->len) {
+            ap_assert(c+result->len <= p+outlen); /* XXX: can be removed after
+                                                   * extensive testing and
+                                                   * review
+                                                   */
+            memcpy(c, result->string, result->len);
+            c += result->len;
+        }
+        result = result->next;
+    } while (result);
+
+    p[outlen] = '\0';
+
+    return p;
+}
+
+/*
+ * perform all the expansions on the environment variables
+ */
+static void do_expand_env(data_item *env, rewrite_ctx *ctx)
+{
+    char *name, *val;
+
+    while (env) {
+        name = do_expand(env->data, ctx, NULL);
+        if (*name == '!') {
+            name++;
+            apr_table_unset(ctx->r->subprocess_env, name);
+            rewritelog((ctx->r, 5, NULL, "unsetting env variable '%s'", name));
+        }
+        else {
+            if ((val = ap_strchr(name, ':')) != NULL) {
+                *val++ = '\0';
+            } else {
+                val = "";
+            }
+
+            apr_table_set(ctx->r->subprocess_env, name, val);
+            rewritelog((ctx->r, 5, NULL, "setting env variable '%s' to '%s'",
+                        name, val));
+        }
+
+        env = env->next;
+    }
+
+    return;
+}
+
+/*
+ * perform all the expansions on the cookies
+ *
+ * TODO: use cached time similar to how logging does it
+ */
+static void add_cookie(request_rec *r, char *s)
+{
+    char *var;
+    char *val;
+    char *domain;
+    char *expires;
+    char *path;
+    char *secure;
+    char *httponly;
+    char *samesite;
+
+    char *tok_cntx;
+    char *cookie;
+    /* long-standing default, but can't use ':' in a cookie */
+    const char *sep = ":"; 
+
+    /* opt-in to ; separator if first character is a ; */
+    if (s && *s == ';') { 
+        sep = ";"; 
+        s++;
+    }
+
+    var = apr_strtok(s, sep, &tok_cntx);
+    val = apr_strtok(NULL, sep, &tok_cntx);
+    domain = apr_strtok(NULL, sep, &tok_cntx);
+
+    if (var && val && domain) {
+        request_rec *rmain = r;
+        char *notename;
+        void *data;
+
+        while (rmain->main) {
+            rmain = rmain->main;
+        }
+
+        notename = apr_pstrcat(rmain->pool, var, "_rewrite", NULL);
+        apr_pool_userdata_get(&data, notename, rmain->pool);
+        if (!data) {
+            char *exp_time = NULL;
+
+            expires = apr_strtok(NULL, sep, &tok_cntx);
+            path = expires ? apr_strtok(NULL, sep, &tok_cntx) : NULL;
+            secure = path ? apr_strtok(NULL, sep, &tok_cntx) : NULL;
+            httponly = secure ? apr_strtok(NULL, sep, &tok_cntx) : NULL;
+            samesite = httponly ? apr_strtok(NULL, sep, &tok_cntx) : NULL;
+
+            if (expires) {
+                apr_time_exp_t tms;
+                long exp_min;
+
+                exp_min = atol(expires);
+                if (exp_min) {
+                    apr_time_exp_gmt(&tms, r->request_time
+                                     + apr_time_from_sec((60 * exp_min)));
+                    exp_time = apr_psprintf(r->pool, "%s, %.2d-%s-%.4d "
+                                                     "%.2d:%.2d:%.2d GMT",
+                                           apr_day_snames[tms.tm_wday],
+                                           tms.tm_mday,
+                                           apr_month_snames[tms.tm_mon],
+                                           tms.tm_year+1900,
+                                           tms.tm_hour, tms.tm_min, tms.tm_sec);
+                }
+            }
+
+            cookie = apr_pstrcat(rmain->pool,
+                                 var, "=", val,
+                                 "; path=", path ? path : "/",
+                                 "; domain=", domain,
+                                 expires ? (exp_time ? "; expires=" : "")
+                                 : NULL,
+                                 expires ? (exp_time ? exp_time : "")
+                                 : NULL,
+                                 (secure && (!ap_cstr_casecmp(secure, "true")
+                                             || !strcmp(secure, "1")
+                                             || !ap_cstr_casecmp(secure,
+                                                            "secure"))) ?
+                                  "; secure" : NULL,
+                                 (httponly && (!ap_cstr_casecmp(httponly, "true")
+                                               || !strcmp(httponly, "1")
+                                               || !ap_cstr_casecmp(httponly,
+                                                              "HttpOnly"))) ?
+                                  "; HttpOnly" : NULL,
+                                 NULL);
+
+            if (samesite && strcmp(samesite, "0") && ap_cstr_casecmp(samesite,"false")) { 
+                cookie = apr_pstrcat(rmain->pool, cookie, "; SameSite=", 
+                                     samesite, NULL);
+            }
+
+            apr_table_addn(rmain->err_headers_out, "Set-Cookie", cookie);
+            apr_pool_userdata_set("set", notename, NULL, rmain->pool);
+            rewritelog((rmain, 5, NULL, "setting cookie '%s'", cookie));
+        }
+        else {
+            rewritelog((rmain, 5, NULL, "skipping already set cookie '%s'",
+                        var));
+        }
+    }
+
+    return;
+}
+
+static void do_expand_cookie(data_item *cookie, rewrite_ctx *ctx)
+{
+    while (cookie) {
+        add_cookie(ctx->r, do_expand(cookie->data, ctx, NULL));
+        cookie = cookie->next;
+    }
+
+    return;
+}
+
+#if APR_HAS_USER
+/*
+ * Expand tilde-paths (/~user) through Unix /etc/passwd
+ * database information (or other OS-specific database)
+ */
+static char *expand_tildepaths(request_rec *r, char *uri)
+{
+    if (uri && *uri == '/' && uri[1] == '~') {
+        char *p, *user;
+
+        p = user = uri + 2;
+        while (*p && *p != '/') {
+            ++p;
+        }
+
+        if (p > user) {
+            char *homedir;
+
+            user = apr_pstrmemdup(r->pool, user, p-user);
+            if (apr_uid_homepath_get(&homedir, user, r->pool) == APR_SUCCESS) {
+                if (*p) {
+                    /* reuse of user variable */
+                    user = homedir + strlen(homedir) - 1;
+                    if (user >= homedir && *user == '/') {
+                        *user = '\0';
+                    }
+
+                    return apr_pstrcat(r->pool, homedir, p, NULL);
+                }
+                else {
+                    return homedir;
+                }
+            }
+        }
+    }
+
+    return uri;
+}
+#endif  /* if APR_HAS_USER */
+
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |              rewriting lockfile support
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+static apr_status_t rewritelock_create(server_rec *s, apr_pool_t *p)
+{
+    apr_status_t rc;
+
+    /* create the lockfile */
+    rc = ap_global_mutex_create(&rewrite_mapr_lock_acquire, NULL,
+                                rewritemap_mutex_type, NULL, s, p, 0);
+    if (rc != APR_SUCCESS) {
+        return rc;
+    }
+
+    return APR_SUCCESS;
+}
+
+static apr_status_t rewritelock_remove(void *data)
+{
+    /* destroy the rewritelock */
+    if (rewrite_mapr_lock_acquire) {
+        apr_global_mutex_destroy(rewrite_mapr_lock_acquire);
+        rewrite_mapr_lock_acquire = NULL;
+    }
+    return APR_SUCCESS;
+}
+
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |           configuration directive handling
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+/*
+ * own command line parser for RewriteRule and RewriteCond,
+ * which doesn't have the '\\' problem.
+ * (returns true on error)
+ *
+ * XXX: what an inclined parser. Seems we have to leave it so
+ *      for backwards compat. *sigh*
+ */
+static int parseargline(char *str, char **a1, char **a2, char **a2_end, char **a3)
+{
+    char quote;
+
+    while (apr_isspace(*str)) {
+        ++str;
+    }
+
+    /*
+     * determine first argument
+     */
+    quote = (*str == '"' || *str == '\'') ? *str++ : '\0';
+    *a1 = str;
+
+    for (; *str; ++str) {
+        if ((apr_isspace(*str) && !quote) || (*str == quote)) {
+            break;
+        }
+        if (*str == '\\' && apr_isspace(str[1])) {
+            ++str;
+            continue;
+        }
+    }
+
+    if (!*str) {
+        return 1;
+    }
+    *str++ = '\0';
+
+    while (apr_isspace(*str)) {
+        ++str;
+    }
+
+    /*
+     * determine second argument
+     */
+    quote = (*str == '"' || *str == '\'') ? *str++ : '\0';
+    *a2 = str;
+
+    for (; *str; ++str) {
+        if ((apr_isspace(*str) && !quote) || (*str == quote)) {
+            break;
+        }
+        if (*str == '\\' && apr_isspace(str[1])) {
+            ++str;
+            continue;
+        }
+    }
+
+    if (!*str) {
+        *a3 = NULL; /* 3rd argument is optional */
+        *a2_end = str;
+        return 0;
+    }
+    *a2_end = str;
+    *str++ = '\0';
+
+    while (apr_isspace(*str)) {
+        ++str;
+    }
+
+    if (!*str) {
+        *a3 = NULL; /* 3rd argument is still optional */
+        return 0;
+    }
+
+    /*
+     * determine third argument
+     */
+    quote = (*str == '"' || *str == '\'') ? *str++ : '\0';
+    *a3 = str;
+    for (; *str; ++str) {
+        if ((apr_isspace(*str) && !quote) || (*str == quote)) {
+            break;
+        }
+        if (*str == '\\' && apr_isspace(str[1])) {
+            ++str;
+            continue;
+        }
+    }
+    *str = '\0';
+
+    return 0;
+}
+
+static void *config_server_create(apr_pool_t *p, server_rec *s)
+{
+    rewrite_server_conf *a;
+
+    a = (rewrite_server_conf *)apr_pcalloc(p, sizeof(rewrite_server_conf));
+
+    a->state           = ENGINE_DISABLED;
+    a->options         = OPTION_NONE;
+    a->rewritemaps     = apr_hash_make(p);
+    a->rewriteconds    = apr_array_make(p, 2, sizeof(rewritecond_entry));
+    a->rewriterules    = apr_array_make(p, 2, sizeof(rewriterule_entry));
+    a->server          = s;
+
+    return (void *)a;
+}
+
+static void *config_server_merge(apr_pool_t *p, void *basev, void *overridesv)
+{
+    rewrite_server_conf *a, *base, *overrides;
+
+    a         = (rewrite_server_conf *)apr_pcalloc(p,
+                                                   sizeof(rewrite_server_conf));
+    base      = (rewrite_server_conf *)basev;
+    overrides = (rewrite_server_conf *)overridesv;
+
+    a->state = (overrides->state_set == 0) ? base->state : overrides->state;
+    a->state_set = overrides->state_set || base->state_set;
+    a->options = (overrides->options_set == 0) ? base->options : overrides->options;
+    a->options_set = overrides->options_set || base->options_set;
+
+    a->server  = overrides->server;
+
+    if (a->options & OPTION_INHERIT ||
+            (base->options & OPTION_INHERIT_DOWN &&
+             !(a->options & OPTION_IGNORE_INHERIT))) {
+        /*
+         *  local directives override
+         *  and anything else is inherited
+         */
+        a->rewritemaps     = apr_hash_overlay(p, overrides->rewritemaps,
+                                              base->rewritemaps);
+        a->rewriteconds    = apr_array_append(p, overrides->rewriteconds,
+                                              base->rewriteconds);
+        a->rewriterules    = apr_array_append(p, overrides->rewriterules,
+                                              base->rewriterules);
+    }
+    else if (a->options & OPTION_INHERIT_BEFORE || 
+            (base->options & OPTION_INHERIT_DOWN_BEFORE &&
+             !(a->options & OPTION_IGNORE_INHERIT))) {
+        /*
+         *  local directives override
+         *  and anything else is inherited (preserving order)
+         */
+        a->rewritemaps     = apr_hash_overlay(p, base->rewritemaps,
+                                              overrides->rewritemaps);
+        a->rewriteconds    = apr_array_append(p, base->rewriteconds,
+                                              overrides->rewriteconds);
+        a->rewriterules    = apr_array_append(p, base->rewriterules,
+                                              overrides->rewriterules);
+    }
+    else {
+        /*
+         *  local directives override
+         *  and anything else gets defaults
+         */
+        a->rewritemaps     = overrides->rewritemaps;
+        a->rewriteconds    = overrides->rewriteconds;
+        a->rewriterules    = overrides->rewriterules;
+    }
+
+    return (void *)a;
+}
+
+static void *config_perdir_create(apr_pool_t *p, char *path)
+{
+    rewrite_perdir_conf *a;
+
+    a = (rewrite_perdir_conf *)apr_pcalloc(p, sizeof(rewrite_perdir_conf));
+
+    a->state           = ENGINE_DISABLED;
+    a->options         = OPTION_NONE;
+    a->baseurl         = NULL;
+    a->rewriteconds    = apr_array_make(p, 2, sizeof(rewritecond_entry));
+    a->rewriterules    = apr_array_make(p, 2, sizeof(rewriterule_entry));
+
+    if (path == NULL) {
+        a->directory = NULL;
+    }
+    else {
+        /* make sure it has a trailing slash */
+        if (path[strlen(path)-1] == '/') {
+            a->directory = apr_pstrdup(p, path);
+        }
+        else {
+            a->directory = apr_pstrcat(p, path, "/", NULL);
+        }
+    }
+
+    return (void *)a;
+}
+
+static void *config_perdir_merge(apr_pool_t *p, void *basev, void *overridesv)
+{
+    rewrite_perdir_conf *a, *base, *overrides;
+
+    a         = (rewrite_perdir_conf *)apr_pcalloc(p,
+                                                  sizeof(rewrite_perdir_conf));
+    base      = (rewrite_perdir_conf *)basev;
+    overrides = (rewrite_perdir_conf *)overridesv;
+
+    a->state = (overrides->state_set == 0) ? base->state : overrides->state;
+    a->state_set = overrides->state_set || base->state_set;
+    a->options = (overrides->options_set == 0) ? base->options : overrides->options;
+    a->options_set = overrides->options_set || base->options_set;
+
+    if (a->options & OPTION_MERGEBASE) { 
+        a->baseurl = (overrides->baseurl_set == 0) ? base->baseurl : overrides->baseurl;
+        a->baseurl_set = overrides->baseurl_set || base->baseurl_set;
+    }
+    else { 
+        a->baseurl = overrides->baseurl;
+    }
+
+    a->directory  = overrides->directory;
+
+    if (a->options & OPTION_INHERIT ||
+            (base->options & OPTION_INHERIT_DOWN &&
+             !(a->options & OPTION_IGNORE_INHERIT))) {
+        a->rewriteconds = apr_array_append(p, overrides->rewriteconds,
+                                           base->rewriteconds);
+        a->rewriterules = apr_array_append(p, overrides->rewriterules,
+                                           base->rewriterules);
+    }
+    else if (a->options & OPTION_INHERIT_BEFORE || 
+            (base->options & OPTION_INHERIT_DOWN_BEFORE &&
+             !(a->options & OPTION_IGNORE_INHERIT))) {
+        a->rewriteconds    = apr_array_append(p, base->rewriteconds,
+                                              overrides->rewriteconds);
+        a->rewriterules    = apr_array_append(p, base->rewriterules,
+                                              overrides->rewriterules);
+    }
+    else {
+        a->rewriteconds = overrides->rewriteconds;
+        a->rewriterules = overrides->rewriterules;
+    }
+
+    return (void *)a;
+}
+
+static const char *cmd_rewriteengine(cmd_parms *cmd,
+                                     void *in_dconf, int flag)
+{
+    rewrite_perdir_conf *dconf = in_dconf;
+    rewrite_server_conf *sconf;
+
+    sconf = ap_get_module_config(cmd->server->module_config, &rewrite_module);
+
+    /* server command? set both global scope and base directory scope */
+    if (cmd->path == NULL) {
+        sconf->state = (flag ? ENGINE_ENABLED : ENGINE_DISABLED);
+        sconf->state_set = 1;
+        dconf->state = sconf->state;
+        dconf->state_set = 1;
+    }
+    /* directory command? set directory scope only */
+    else {
+        dconf->state = (flag ? ENGINE_ENABLED : ENGINE_DISABLED);
+        dconf->state_set = 1;
+    }
+
+    return NULL;
+}
+
+static const char *cmd_rewriteoptions(cmd_parms *cmd,
+                                      void *in_dconf, const char *option)
+{
+    int options = 0;
+
+    while (*option) {
+        char *w = ap_getword_conf(cmd->temp_pool, &option);
+
+        if (!strcasecmp(w, "inherit")) {
+            options |= OPTION_INHERIT;
+        }
+        else if (!strcasecmp(w, "inheritbefore")) {
+            options |= OPTION_INHERIT_BEFORE;
+        }
+        else if (!strcasecmp(w, "inheritdown")) {
+            options |= OPTION_INHERIT_DOWN;
+        }
+        else if(!strcasecmp(w, "inheritdownbefore")) {
+            options |= OPTION_INHERIT_DOWN_BEFORE;
+        }
+        else if (!strcasecmp(w, "ignoreinherit")) {
+            options |= OPTION_IGNORE_INHERIT;
+        }
+        else if (!strcasecmp(w, "allownoslash")) {
+            options |= OPTION_NOSLASH;
+        }
+        else if (!strncasecmp(w, "MaxRedirects=", 13)) {
+            ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server, APLOGNO(00664)
+                         "RewriteOptions: MaxRedirects option has been "
+                         "removed in favor of the global "
+                         "LimitInternalRecursion directive and will be "
+                         "ignored.");
+        }
+        else if (!strcasecmp(w, "allowanyuri")) {
+            options |= OPTION_ANYURI;
+        }
+        else if (!strcasecmp(w, "mergebase")) {
+            options |= OPTION_MERGEBASE;
+        }
+        else if (!strcasecmp(w, "ignorecontextinfo")) {
+            options |= OPTION_IGNORE_CONTEXT_INFO;
+        }
+        else if (!strcasecmp(w, "legacyprefixdocroot")) {
+            options |= OPTION_LEGACY_PREFIX_DOCROOT;
+        }
+        else {
+            return apr_pstrcat(cmd->pool, "RewriteOptions: unknown option '",
+                               w, "'", NULL);
+        }
+    }
+
+    /* server command? set both global scope and base directory scope */
+    if (cmd->path == NULL) { /* is server command */
+        rewrite_perdir_conf *dconf = in_dconf;
+        rewrite_server_conf *sconf =
+            ap_get_module_config(cmd->server->module_config,
+                                 &rewrite_module);
+
+        sconf->options |= options;
+        sconf->options_set = 1;
+        dconf->options |= options;
+        dconf->options_set = 1;
+    }
+    /* directory command? set directory scope only */
+    else {                  /* is per-directory command */
+        rewrite_perdir_conf *dconf = in_dconf;
+
+        dconf->options |= options;
+        dconf->options_set = 1;
+    }
+
+    return NULL;
+}
+
+static const char *cmd_rewritemap(cmd_parms *cmd, void *dconf, const char *a1,
+                                  const char *a2, const char *a3)
+{
+    rewrite_server_conf *sconf;
+    rewritemap_entry *newmap;
+    apr_finfo_t st;
+    const char *fname;
+
+    sconf = ap_get_module_config(cmd->server->module_config, &rewrite_module);
+
+    newmap = apr_pcalloc(cmd->pool, sizeof(rewritemap_entry));
+
+    if (strncasecmp(a2, "txt:", 4) == 0) {
+        if ((fname = ap_server_root_relative(cmd->pool, a2+4)) == NULL) {
+            return apr_pstrcat(cmd->pool, "RewriteMap: bad path to txt map: ",
+                               a2+4, NULL);
+        }
+
+        newmap->type      = MAPTYPE_TXT;
+        newmap->datafile  = fname;
+        newmap->checkfile = fname;
+        newmap->cachename = apr_psprintf(cmd->pool, "%pp:%s",
+                                         (void *)cmd->server, a1);
+    }
+    else if (strncasecmp(a2, "rnd:", 4) == 0) {
+        if ((fname = ap_server_root_relative(cmd->pool, a2+4)) == NULL) {
+            return apr_pstrcat(cmd->pool, "RewriteMap: bad path to rnd map: ",
+                               a2+4, NULL);
+        }
+
+        newmap->type      = MAPTYPE_RND;
+        newmap->datafile  = fname;
+        newmap->checkfile = fname;
+        newmap->cachename = apr_psprintf(cmd->pool, "%pp:%s",
+                                         (void *)cmd->server, a1);
+    }
+    else if (strncasecmp(a2, "dbm", 3) == 0) {
+        apr_status_t rv;
+
+        newmap->type = MAPTYPE_DBM;
+        fname = NULL;
+        newmap->cachename = apr_psprintf(cmd->pool, "%pp:%s",
+                                         (void *)cmd->server, a1);
+
+        if (a2[3] == ':') {
+            newmap->dbmtype = "default";
+            fname = a2+4;
+        }
+        else if (a2[3] == '=') {
+            const char *colon = ap_strchr_c(a2 + 4, ':');
+
+            if (colon) {
+                newmap->dbmtype = apr_pstrndup(cmd->pool, a2 + 4,
+                                               colon - (a2 + 3) - 1);
+                fname = colon + 1;
+            }
+        }
+
+        if (!fname) {
+            return apr_pstrcat(cmd->pool, "RewriteMap: bad map:",
+                               a2, NULL);
+        }
+
+        if ((newmap->datafile = ap_server_root_relative(cmd->pool,
+                                                        fname)) == NULL) {
+            return apr_pstrcat(cmd->pool, "RewriteMap: bad path to dbm map: ",
+                               fname, NULL);
+        }
+
+        rv = apr_dbm_get_usednames_ex(cmd->pool, newmap->dbmtype,
+                                      newmap->datafile, &newmap->checkfile,
+                                      &newmap->checkfile2);
+        if (rv != APR_SUCCESS) {
+            return apr_pstrcat(cmd->pool, "RewriteMap: dbm type ",
+                               newmap->dbmtype, " is invalid", NULL);
+        }
+    }
+    else if ((strncasecmp(a2, "dbd:", 4) == 0)
+             || (strncasecmp(a2, "fastdbd:", 8) == 0)) {
+        if (dbd_prepare == NULL) {
+            return "RewriteMap types dbd and fastdbd require mod_dbd!";
+        }
+        if ((a2[0] == 'd') || (a2[0] == 'D')) {
+            newmap->type = MAPTYPE_DBD;
+            fname = a2+4;
+        }
+        else {
+            newmap->type = MAPTYPE_DBD_CACHE;
+            fname = a2+8;
+            newmap->cachename = apr_psprintf(cmd->pool, "%pp:%s",
+                                             (void *)cmd->server, a1);
+        }
+        newmap->dbdq = a1;
+        dbd_prepare(cmd->server, fname, newmap->dbdq);
+    }
+    else if (strncasecmp(a2, "prg:", 4) == 0) {
+        apr_tokenize_to_argv(a2 + 4, &newmap->argv, cmd->pool);
+
+        fname = newmap->argv[0];
+        if ((newmap->argv[0] = ap_server_root_relative(cmd->pool,
+                                                       fname)) == NULL) {
+            return apr_pstrcat(cmd->pool, "RewriteMap: bad path to prg map: ",
+                               fname, NULL);
+        }
+
+        newmap->type      = MAPTYPE_PRG;
+        newmap->checkfile = newmap->argv[0];
+        rewrite_lock_needed = 1;
+
+        if (a3) {
+            char *tok_cntx;
+            newmap->user = apr_strtok(apr_pstrdup(cmd->pool, a3), ":", &tok_cntx);
+            newmap->group = apr_strtok(NULL, ":", &tok_cntx);
+        }
+    }
+    else if (strncasecmp(a2, "int:", 4) == 0) {
+        newmap->type      = MAPTYPE_INT;
+        newmap->func      = (char *(*)(request_rec *,char *))
+                            apr_hash_get(mapfunc_hash, a2+4, strlen(a2+4));
+        if (newmap->func == NULL) {
+            return apr_pstrcat(cmd->pool, "RewriteMap: internal map not found:",
+                               a2+4, NULL);
+        }
+    }
+    else {
+        if ((fname = ap_server_root_relative(cmd->pool, a2)) == NULL) {
+            return apr_pstrcat(cmd->pool, "RewriteMap: bad path to txt map: ",
+                               a2, NULL);
+        }
+
+        newmap->type      = MAPTYPE_TXT;
+        newmap->datafile  = fname;
+        newmap->checkfile = fname;
+        newmap->cachename = apr_psprintf(cmd->pool, "%pp:%s",
+                                         (void *)cmd->server, a1);
+    }
+
+    if (newmap->checkfile
+        && (apr_stat(&st, newmap->checkfile, APR_FINFO_MIN,
+                     cmd->pool) != APR_SUCCESS)) {
+        return apr_pstrcat(cmd->pool,
+                           "RewriteMap: file for map ", a1,
+                           " not found:", newmap->checkfile, NULL);
+    }
+
+    apr_hash_set(sconf->rewritemaps, a1, APR_HASH_KEY_STRING, newmap);
+
+    return NULL;
+}
+
+static const char *cmd_rewritebase(cmd_parms *cmd, void *in_dconf,
+                                   const char *a1)
+{
+    rewrite_perdir_conf *dconf = in_dconf;
+
+    if (cmd->path == NULL || dconf == NULL) {
+        return "RewriteBase: only valid in per-directory config files";
+    }
+    if (a1[0] == '\0') {
+        return "RewriteBase: empty URL not allowed";
+    }
+    if (a1[0] != '/') {
+        return "RewriteBase: argument is not a valid URL";
+    }
+
+    dconf->baseurl = a1;
+    dconf->baseurl_set = 1;
+
+    return NULL;
+}
+
+/*
+ * generic lexer for RewriteRule and RewriteCond flags.
+ * The parser will be passed in as a function pointer
+ * and called if a flag was found
+ */
+static const char *cmd_parseflagfield(apr_pool_t *p, void *cfg, char *key,
+                                      const char *(*parse)(apr_pool_t *,
+                                                           void *,
+                                                           char *, char *))
+{
+    char *val, *nextp, *endp;
+    const char *err;
+
+    endp = key + strlen(key) - 1;
+    if (*key != '[' || *endp != ']') {
+        return "bad flag delimiters";
+    }
+
+    *endp = ','; /* for simpler parsing */
+    ++key;
+
+    while (*key) {
+        /* skip leading spaces */
+        while (apr_isspace(*key)) {
+            ++key;
+        }
+
+        if (!*key || (nextp = ap_strchr(key, ',')) == NULL) { /* NULL should not
+                                                               * happen, but ...
+                                                               */
+            break;
+        }
+
+        /* strip trailing spaces */
+        endp = nextp - 1;
+        while (apr_isspace(*endp)) {
+            --endp;
+        }
+        *++endp = '\0';
+
+        /* split key and val */
+        val = ap_strchr(key, '=');
+        if (val) {
+            *val++ = '\0';
+        }
+        else {
+            val = endp;
+        }
+
+        err = parse(p, cfg, key, val);
+        if (err) {
+            return err;
+        }
+
+        key = nextp + 1;
+    }
+
+    return NULL;
+}
+
+static const char *cmd_rewritecond_setflag(apr_pool_t *p, void *_cfg,
+                                           char *key, char *val)
+{
+    rewritecond_entry *cfg = _cfg;
+
+    if (   strcasecmp(key, "nocase") == 0
+        || strcasecmp(key, "NC") == 0    ) {
+        cfg->flags |= CONDFLAG_NOCASE;
+    }
+    else if (   strcasecmp(key, "ornext") == 0
+             || strcasecmp(key, "OR") == 0    ) {
+        cfg->flags |= CONDFLAG_ORNEXT;
+    }
+    else if (   strcasecmp(key, "novary") == 0
+             || strcasecmp(key, "NV") == 0    ) {
+        cfg->flags |= CONDFLAG_NOVARY;
+    }
+    else {
+        return apr_pstrcat(p, "unknown flag '", key, "'", NULL);
+    }
+    return NULL;
+}
+
+static const char *cmd_rewritecond(cmd_parms *cmd, void *in_dconf,
+                                   const char *in_str)
+{
+    rewrite_perdir_conf *dconf = in_dconf;
+    char *str = apr_pstrdup(cmd->pool, in_str);
+    rewrite_server_conf *sconf;
+    rewritecond_entry *newcond;
+    ap_regex_t *regexp;
+    char *a1 = NULL, *a2 = NULL, *a2_end, *a3 = NULL;
+    const char *err;
+
+    sconf = ap_get_module_config(cmd->server->module_config, &rewrite_module);
+
+    /*  make a new entry in the internal temporary rewrite rule list */
+    if (cmd->path == NULL) {   /* is server command */
+        newcond = apr_array_push(sconf->rewriteconds);
+    }
+    else {                     /* is per-directory command */
+        newcond = apr_array_push(dconf->rewriteconds);
+    }
+
+    /* parse the argument line ourself
+     * a1 .. a3 are substrings of str, which is a fresh copy
+     * of the argument line. So we can use a1 .. a3 without
+     * copying them again.
+     */
+    if (parseargline(str, &a1, &a2, &a2_end, &a3)) {
+        return apr_pstrcat(cmd->pool, "RewriteCond: bad argument line '", str,
+                           "'", NULL);
+    }
+
+    /* arg1: the input string */
+    newcond->input = a1;
+
+    /* arg3: optional flags field
+     * (this has to be parsed first, because we need to
+     *  know if the regex should be compiled with ICASE!)
+     */
+    newcond->flags = CONDFLAG_NONE;
+    if (a3 != NULL) {
+        if ((err = cmd_parseflagfield(cmd->pool, newcond, a3,
+                                      cmd_rewritecond_setflag)) != NULL) {
+            return apr_pstrcat(cmd->pool, "RewriteCond: ", err, NULL);
+        }
+    }
+
+    /* arg2: the pattern */
+    newcond->pattern = a2;
+    if (*a2 == '!') {
+        newcond->flags |= CONDFLAG_NOTMATCH;
+        ++a2;
+    }
+
+    /* determine the pattern type */
+    newcond->ptype = CONDPAT_REGEX;
+    if (strcasecmp(a1, "expr") == 0) {
+        newcond->ptype = CONDPAT_AP_EXPR;
+    }
+    else if (*a2 && a2[1]) {
+        if (*a2 == '-') {
+            if (!a2[2]) {
+                switch (a2[1]) {
+                case 'f': newcond->ptype = CONDPAT_FILE_EXISTS; break;
+                case 's': newcond->ptype = CONDPAT_FILE_SIZE;   break;
+                case 'd': newcond->ptype = CONDPAT_FILE_DIR;    break;
+                case 'x': newcond->ptype = CONDPAT_FILE_XBIT;   break;
+                case 'h': newcond->ptype = CONDPAT_FILE_LINK;   break;
+                case 'L': newcond->ptype = CONDPAT_FILE_LINK;   break;
+                case 'l': newcond->ptype = CONDPAT_FILE_LINK;   break;
+                case 'U': newcond->ptype = CONDPAT_LU_URL;      break;
+                case 'F': newcond->ptype = CONDPAT_LU_FILE;     break;
+                }
+            }
+            else if (a2[3]) {
+                switch (a2[1]) {
+                case 'l':
+                    if (a2[2] == 't') {
+                        a2 += 3;
+                        newcond->ptype = CONDPAT_INT_LT;
+                    }
+                    else if (a2[2] == 'e') {
+                        a2 += 3;
+                        newcond->ptype = CONDPAT_INT_LE;
+                    }
+                    break;
+
+                case 'g':
+                    if (a2[2] == 't') {
+                        a2 += 3;
+                        newcond->ptype = CONDPAT_INT_GT;
+                    }
+                    else if (a2[2] == 'e') {
+                        a2 += 3;
+                        newcond->ptype = CONDPAT_INT_GE;
+                    }
+                    break;
+
+                case 'e':
+                    if (a2[2] == 'q') {
+                        a2 += 3;
+                        newcond->ptype = CONDPAT_INT_EQ;
+                    }
+                    break;
+
+                case 'n':
+                    if (a2[2] == 'e') {
+                        /* Inversion, ensure !-ne == -eq */
+                        a2 += 3;
+                        newcond->ptype = CONDPAT_INT_EQ;
+                        newcond->flags ^= CONDFLAG_NOTMATCH;
+                    }
+                    break;
+                }
+            }
+        }
+        else {
+            switch (*a2) {
+            case '>': if (*++a2 == '=')
+                          ++a2, newcond->ptype = CONDPAT_STR_GE;
+                      else
+                          newcond->ptype = CONDPAT_STR_GT;
+                      break;
+
+            case '<': if (*++a2 == '=')
+                          ++a2, newcond->ptype = CONDPAT_STR_LE;
+                      else
+                          newcond->ptype = CONDPAT_STR_LT;
+                      break;
+
+            case '=': newcond->ptype = CONDPAT_STR_EQ;
+                      /* "" represents an empty string */
+                      if (*++a2 == '"' && a2[1] == '"' && !a2[2])
+                          a2 += 2;
+                      break;
+            }
+        }
+    }
+
+    if ((newcond->ptype != CONDPAT_REGEX) &&
+        (newcond->ptype < CONDPAT_STR_LT || newcond->ptype > CONDPAT_STR_GE) &&
+        (newcond->flags & CONDFLAG_NOCASE)) {
+        ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server, APLOGNO(00665)
+                     "RewriteCond: NoCase option for non-regex pattern '%s' "
+                     "is not supported and will be ignored. (%s:%d)", a2,
+                     cmd->directive->filename, cmd->directive->line_num);
+        newcond->flags &= ~CONDFLAG_NOCASE;
+    }
+
+    newcond->pskip = a2 - newcond->pattern;
+    newcond->pattern += newcond->pskip;
+
+    if (newcond->ptype == CONDPAT_REGEX) {
+        regexp = ap_pregcomp(cmd->pool, a2,
+                             AP_REG_EXTENDED | ((newcond->flags & CONDFLAG_NOCASE)
+                                             ? AP_REG_ICASE : 0));
+        if (!regexp) {
+            return apr_pstrcat(cmd->pool, "RewriteCond: cannot compile regular "
+                               "expression '", a2, "'", NULL);
+        }
+
+        newcond->regexp  = regexp;
+    }
+    else if (newcond->ptype == CONDPAT_AP_EXPR) {
+        unsigned int flags = newcond->flags & CONDFLAG_NOVARY ?
+                             AP_EXPR_FLAG_DONT_VARY : 0;
+        newcond->expr = ap_expr_parse_cmd(cmd, a2, flags, &err, NULL);
+        if (err)
+            return apr_psprintf(cmd->pool, "RewriteCond: cannot compile "
+                                "expression \"%s\": %s", a2, err);
+    }
+
+    return NULL;
+}
+
+static const char *cmd_rewriterule_setflag(apr_pool_t *p, void *_cfg,
+                                           char *key, char *val)
+{
+    rewriterule_entry *cfg = _cfg;
+    int error = 0;
+
+    switch (*key++) {
+    case 'b':
+    case 'B':
+        if (!*key || !strcasecmp(key, "ackrefescaping")) {
+            cfg->flags |= RULEFLAG_ESCAPEBACKREF;
+            if (val && *val) {
+                cfg->escapes = val;
+            }
+        }
+        else if (!strcasecmp(key, "NE")) {
+            if (val && *val) {
+                cfg->noescapes = val;
+            }
+            else {
+                return "flag 'BNE' wants a list of characters (i.e. [BNE=...])";
+            }
+        }
+        else if (!strcasecmp(key, "NP") || !strcasecmp(key, "ackrefernoplus")) { 
+            cfg->flags |= RULEFLAG_ESCAPENOPLUS;
+        }
+        else if (!strcasecmp(key, "CTLS")) {
+            cfg->flags |= RULEFLAG_ESCAPECTLS|RULEFLAG_ESCAPEBACKREF;
+        }
+        else {
+            ++error;
+        }
+        break;
+    case 'c':
+    case 'C':
+        if (!*key || !strcasecmp(key, "hain")) {           /* chain */
+            cfg->flags |= RULEFLAG_CHAIN;
+        }
+        else if (((*key == 'O' || *key == 'o') && !key[1])
+                 || !strcasecmp(key, "ookie")) {           /* cookie */
+            data_item *cp = cfg->cookie;
+
+            if (!cp) {
+                cp = cfg->cookie = apr_palloc(p, sizeof(*cp));
+            }
+            else {
+                while (cp->next) {
+                    cp = cp->next;
+                }
+                cp->next = apr_palloc(p, sizeof(*cp));
+                cp = cp->next;
+            }
+
+            cp->next = NULL;
+            cp->data = val;
+        }
+        else {
+            ++error;
+        }
+        break;
+    case 'd':
+    case 'D':
+        if (!*key || !strcasecmp(key, "PI") || !strcasecmp(key,"iscardpath")) {
+            cfg->flags |= (RULEFLAG_DISCARDPATHINFO);
+        }
+        break;
+    case 'e':
+    case 'E':
+        if (!*key || !strcasecmp(key, "nv")) {             /* env */
+            data_item *cp = cfg->env;
+
+            if (!cp) {
+                cp = cfg->env = apr_palloc(p, sizeof(*cp));
+            }
+            else {
+                while (cp->next) {
+                    cp = cp->next;
+                }
+                cp->next = apr_palloc(p, sizeof(*cp));
+                cp = cp->next;
+            }
+
+            cp->next = NULL;
+            cp->data = val;
+        }
+        else if (!strcasecmp(key, "nd")) {                /* end */
+            cfg->flags |= RULEFLAG_END;
+        }
+        else {
+            ++error;
+        }
+        break;
+
+    case 'f':
+    case 'F':
+        if (!*key || !strcasecmp(key, "orbidden")) {       /* forbidden */
+            cfg->flags |= (RULEFLAG_STATUS | RULEFLAG_NOSUB);
+            cfg->forced_responsecode = HTTP_FORBIDDEN;
+        }
+        else {
+            ++error;
+        }
+        break;
+
+    case 'g':
+    case 'G':
+        if (!*key || !strcasecmp(key, "one")) {            /* gone */
+            cfg->flags |= (RULEFLAG_STATUS | RULEFLAG_NOSUB);
+            cfg->forced_responsecode = HTTP_GONE;
+        }
+        else {
+            ++error;
+        }
+        break;
+
+    case 'h':
+    case 'H':
+        if (!*key || !strcasecmp(key, "andler")) {         /* handler */
+            cfg->forced_handler = val;
+        }
+        else {
+            ++error;
+        }
+        break;
+    case 'l':
+    case 'L':
+        if (!*key || !strcasecmp(key, "ast")) {            /* last */
+            cfg->flags |= RULEFLAG_LASTRULE;
+        }
+        else {
+            ++error;
+        }
+        break;
+
+    case 'n':
+    case 'N':
+        if (((*key == 'E' || *key == 'e') && !key[1])
+            || !strcasecmp(key, "oescape")) {              /* noescape */
+            cfg->flags |= RULEFLAG_NOESCAPE;
+        }
+        else if (!*key || !strcasecmp(key, "ext")) {       /* next */
+            cfg->flags |= RULEFLAG_NEWROUND;
+            if (val && *val) { 
+                cfg->maxrounds = atoi(val);
+            }
+
+        }
+        else if (((*key == 'S' || *key == 's') && !key[1])
+            || !strcasecmp(key, "osubreq")) {              /* nosubreq */
+            cfg->flags |= RULEFLAG_IGNOREONSUBREQ;
+        }
+        else if (((*key == 'C' || *key == 'c') && !key[1])
+            || !strcasecmp(key, "ocase")) {                /* nocase */
+            cfg->flags |= RULEFLAG_NOCASE;
+        }
+        else {
+            ++error;
+        }
+        break;
+
+    case 'p':
+    case 'P':
+        if (!*key || !strcasecmp(key, "roxy")) {           /* proxy */
+            cfg->flags |= RULEFLAG_PROXY;
+        }
+        else if (((*key == 'T' || *key == 't') && !key[1])
+            || !strcasecmp(key, "assthrough")) {           /* passthrough */
+            cfg->flags |= RULEFLAG_PASSTHROUGH;
+        }
+        else {
+            ++error;
+        }
+        break;
+
+    case 'q':
+    case 'Q':
+        if (   !strcasecmp(key, "SA")
+            || !strcasecmp(key, "sappend")) {              /* qsappend */
+            cfg->flags |= RULEFLAG_QSAPPEND;
+        } else if ( !strcasecmp(key, "SD")
+                || !strcasecmp(key, "sdiscard") ) {       /* qsdiscard */
+            cfg->flags |= RULEFLAG_QSDISCARD;
+        } else if ( !strcasecmp(key, "SL")
+                || !strcasecmp(key, "slast") ) {          /* qslast */
+            cfg->flags |= RULEFLAG_QSLAST;
+        }
+        else {
+            ++error;
+        }
+        break;
+
+    case 'r':
+    case 'R':
+        if (!*key || !strcasecmp(key, "edirect")) {        /* redirect */
+            int status = 0;
+
+            cfg->flags |= RULEFLAG_FORCEREDIRECT;
+            if (*val) {
+                if (strcasecmp(val, "permanent") == 0) {
+                    status = HTTP_MOVED_PERMANENTLY;
+                }
+                else if (strcasecmp(val, "temp") == 0) {
+                    status = HTTP_MOVED_TEMPORARILY;
+                }
+                else if (strcasecmp(val, "seeother") == 0) {
+                    status = HTTP_SEE_OTHER;
+                }
+                else if (apr_isdigit(*val)) {
+                    status = atoi(val);
+                    if (status != HTTP_INTERNAL_SERVER_ERROR) {
+                        int idx =
+                            ap_index_of_response(HTTP_INTERNAL_SERVER_ERROR);
+
+                        if (ap_index_of_response(status) == idx) {
+                            return apr_psprintf(p, "invalid HTTP "
+                                                   "response code '%s' for "
+                                                   "flag 'R'",
+                                                val);
+                        }
+                    }
+                    if (!ap_is_HTTP_REDIRECT(status)) {
+                        cfg->flags |= (RULEFLAG_STATUS | RULEFLAG_NOSUB);
+                    }
+                }
+                cfg->forced_responsecode = status;
+            }
+        }
+        else {
+            ++error;
+        }
+        break;
+
+    case 's':
+    case 'S':
+        if (!*key || !strcasecmp(key, "kip")) {            /* skip */
+            cfg->skip = atoi(val);
+        }
+        else {
+            ++error;
+        }
+        break;
+
+    case 't':
+    case 'T':
+        if (!*key || !strcasecmp(key, "ype")) {            /* type */
+            cfg->forced_mimetype = val;
+        }
+        else {
+            ++error;
+        }
+        break;
+    default:
+        ++error;
+        break;
+    }
+
+    if (error) {
+        return apr_pstrcat(p, "unknown flag '", --key, "'", NULL);
+    }
+
+    return NULL;
+}
+
+static const char *cmd_rewriterule(cmd_parms *cmd, void *in_dconf,
+                                   const char *in_str)
+{
+    rewrite_perdir_conf *dconf = in_dconf;
+    char *str = apr_pstrdup(cmd->pool, in_str);
+    rewrite_server_conf *sconf;
+    rewriterule_entry *newrule;
+    ap_regex_t *regexp;
+    char *a1 = NULL, *a2 = NULL, *a2_end, *a3 = NULL;
+    const char *err;
+
+    sconf = ap_get_module_config(cmd->server->module_config, &rewrite_module);
+
+    /*  make a new entry in the internal rewrite rule list */
+    if (cmd->path == NULL) {   /* is server command */
+        newrule = apr_array_push(sconf->rewriterules);
+    }
+    else {                     /* is per-directory command */
+        newrule = apr_array_push(dconf->rewriterules);
+    }
+
+    /*  parse the argument line ourself */
+    if (parseargline(str, &a1, &a2, &a2_end, &a3)) {
+        return apr_pstrcat(cmd->pool, "RewriteRule: bad argument line '", str,
+                           "'", NULL);
+    }
+
+    newrule->forced_mimetype     = NULL;
+    newrule->forced_handler      = NULL;
+    newrule->forced_responsecode = HTTP_MOVED_TEMPORARILY;
+    newrule->flags  = RULEFLAG_NONE;
+    newrule->env = NULL;
+    newrule->cookie = NULL;
+    newrule->skip   = 0;
+    newrule->maxrounds = REWRITE_MAX_ROUNDS;
+    newrule->escapes = newrule->noescapes = NULL;
+
+    /* arg3: optional flags field */
+    if (a3 != NULL) {
+        if ((err = cmd_parseflagfield(cmd->pool, newrule, a3,
+                                      cmd_rewriterule_setflag)) != NULL) {
+            return apr_pstrcat(cmd->pool, "RewriteRule: ", err, NULL);
+        }
+    }
+
+    /* arg1: the pattern
+     * try to compile the regexp to test if is ok
+     */
+    if (*a1 == '!') {
+        newrule->flags |= RULEFLAG_NOTMATCH;
+        ++a1;
+    }
+
+    regexp = ap_pregcomp(cmd->pool, a1, AP_REG_EXTENDED |
+                                        ((newrule->flags & RULEFLAG_NOCASE)
+                                         ? AP_REG_ICASE : 0));
+    if (!regexp) {
+        return apr_pstrcat(cmd->pool,
+                           "RewriteRule: cannot compile regular expression '",
+                           a1, "'", NULL);
+    }
+
+    newrule->pattern = a1;
+    newrule->regexp  = regexp;
+
+    /* arg2: the output string */
+    newrule->output = a2;
+    if (*a2 == '-' && !a2[1]) {
+        newrule->flags |= RULEFLAG_NOSUB;
+    }
+
+    if (*(a2_end-1) == '?') {
+        /* a literal ? at the end of the unsubstituted rewrite rule */
+        newrule->flags |= RULEFLAG_QSNONE;
+        *(a2_end-1) = '\0'; /* trailing ? has done its job */
+    }
+    else if (newrule->flags & RULEFLAG_QSDISCARD) {
+        if (NULL == ap_strchr(newrule->output, '?')) {
+            newrule->flags |= RULEFLAG_QSNONE;
+        }
+    }
+
+    /* now, if the server or per-dir config holds an
+     * array of RewriteCond entries, we take it for us
+     * and clear the array
+     */
+    if (cmd->path == NULL) {  /* is server command */
+        newrule->rewriteconds   = sconf->rewriteconds;
+        sconf->rewriteconds = apr_array_make(cmd->pool, 2,
+                                             sizeof(rewritecond_entry));
+    }
+    else {                    /* is per-directory command */
+        newrule->rewriteconds   = dconf->rewriteconds;
+        dconf->rewriteconds = apr_array_make(cmd->pool, 2,
+                                             sizeof(rewritecond_entry));
+    }
+
+    return NULL;
+}
+
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |                  the rewriting engine
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+/* Lexicographic Compare */
+static APR_INLINE int compare_lexicography(char *a, char *b)
+{
+    apr_size_t i, lena, lenb;
+
+    lena = strlen(a);
+    lenb = strlen(b);
+
+    if (lena == lenb) {
+        for (i = 0; i < lena; ++i) {
+            if (a[i] != b[i]) {
+                return ((unsigned char)a[i] > (unsigned char)b[i]) ? 1 : -1;
+            }
+        }
+
+        return 0;
+    }
+
+    return ((lena > lenb) ? 1 : -1);
+}
+
+/*
+ * Apply a single rewriteCond
+ */
+static int apply_rewrite_cond(rewritecond_entry *p, rewrite_ctx *ctx)
+{
+    char *input = NULL;
+    apr_finfo_t sb;
+    request_rec *rsub, *r = ctx->r;
+    ap_regmatch_t regmatch[AP_MAX_REG_MATCH];
+    int rc = 0;
+    int basis;
+
+    if (p->ptype != CONDPAT_AP_EXPR)
+        input = do_expand(p->input, ctx, NULL);
+
+    switch (p->ptype) {
+    case CONDPAT_FILE_EXISTS:
+        if (   apr_stat(&sb, input, APR_FINFO_MIN, r->pool) == APR_SUCCESS
+            && sb.filetype == APR_REG) {
+            rc = 1;
+        }
+        break;
+
+    case CONDPAT_FILE_SIZE:
+        if (   apr_stat(&sb, input, APR_FINFO_MIN, r->pool) == APR_SUCCESS
+            && sb.filetype == APR_REG && sb.size > 0) {
+            rc = 1;
+        }
+        break;
+
+    case CONDPAT_FILE_LINK:
+#if !defined(OS2)
+        if (   apr_stat(&sb, input, APR_FINFO_MIN | APR_FINFO_LINK,
+                        r->pool) == APR_SUCCESS
+            && sb.filetype == APR_LNK) {
+            rc = 1;
+        }
+#endif
+        break;
+
+    case CONDPAT_FILE_DIR:
+        if (   apr_stat(&sb, input, APR_FINFO_MIN, r->pool) == APR_SUCCESS
+            && sb.filetype == APR_DIR) {
+            rc = 1;
+        }
+        break;
+
+    case CONDPAT_FILE_XBIT:
+        if (   apr_stat(&sb, input, APR_FINFO_PROT, r->pool) == APR_SUCCESS
+            && (sb.protection & (APR_UEXECUTE | APR_GEXECUTE | APR_WEXECUTE))) {
+            rc = 1;
+        }
+        break;
+
+    case CONDPAT_LU_URL:
+        if (*input && subreq_ok(r)) {
+            rsub = ap_sub_req_lookup_uri(input, r, NULL);
+            if (rsub->status < 400) {
+                rc = 1;
+            }
+            rewritelog((r, 5, NULL, "RewriteCond URI (-U) check: "
+                        "path=%s -> status=%d", input, rsub->status));
+            ap_destroy_sub_req(rsub);
+        }
+        break;
+
+    case CONDPAT_LU_FILE:
+        if (*input && subreq_ok(r)) {
+            rsub = ap_sub_req_lookup_file(input, r, NULL);
+            if (rsub->status < 300 &&
+                /* double-check that file exists since default result is 200 */
+                apr_stat(&sb, rsub->filename, APR_FINFO_MIN,
+                         r->pool) == APR_SUCCESS) {
+                rc = 1;
+            }
+            rewritelog((r, 5, NULL, "RewriteCond file (-F) check: path=%s "
+                        "-> file=%s status=%d", input, rsub->filename,
+                        rsub->status));
+            ap_destroy_sub_req(rsub);
+        }
+        break;
+
+    case CONDPAT_STR_GE:
+        basis = 0;
+        goto test_str_g;
+    case CONDPAT_STR_GT:
+        basis = 1;
+test_str_g:
+        if (p->flags & CONDFLAG_NOCASE) {
+            rc = (strcasecmp(input, p->pattern) >= basis) ? 1 : 0;
+        }
+        else {
+            rc = (compare_lexicography(input, p->pattern) >= basis) ? 1 : 0;
+        }
+        break;
+
+    case CONDPAT_STR_LE:
+        basis = 0;
+        goto test_str_l;
+    case CONDPAT_STR_LT:
+        basis = -1;
+test_str_l:
+        if (p->flags & CONDFLAG_NOCASE) {
+            rc = (strcasecmp(input, p->pattern) <= basis) ? 1 : 0;
+        }
+        else {
+            rc = (compare_lexicography(input, p->pattern) <= basis) ? 1 : 0;
+        }
+        break;
+
+    case CONDPAT_STR_EQ:
+        /* Note: the only type where the operator is dropped from p->pattern */
+        if (p->flags & CONDFLAG_NOCASE) {
+            rc = !strcasecmp(input, p->pattern);
+        }
+        else {
+            rc = !strcmp(input, p->pattern);
+        }
+        break;
+
+    case CONDPAT_INT_GE: rc = (atoi(input) >= atoi(p->pattern)); break;
+    case CONDPAT_INT_GT: rc = (atoi(input) > atoi(p->pattern));  break;
+
+    case CONDPAT_INT_LE: rc = (atoi(input) <= atoi(p->pattern)); break;
+    case CONDPAT_INT_LT: rc = (atoi(input) < atoi(p->pattern));  break;
+
+    case CONDPAT_INT_EQ: rc = (atoi(input) == atoi(p->pattern)); break;
+
+    case CONDPAT_AP_EXPR:
+        {
+            const char *err, *source;
+            rc = ap_expr_exec_re(r, p->expr, AP_MAX_REG_MATCH, regmatch,
+                                 &source, &err);
+            if (rc < 0 || err) {
+                rewritelog((r, 1, ctx->perdir,
+                            "RewriteCond: expr='%s' evaluation failed: %s",
+                            p->pattern - p->pskip, err));
+                rc = 0;
+            }
+            /* update briRC backref info */
+            if (rc && !(p->flags & CONDFLAG_NOTMATCH)) {
+                ctx->briRC.source = source;
+                memcpy(ctx->briRC.regmatch, regmatch, sizeof(regmatch));
+            }
+        }
+        break;
+    default:
+        /* it is really a regexp pattern, so apply it */
+        rc = !ap_regexec(p->regexp, input, AP_MAX_REG_MATCH, regmatch, 0);
+
+        /* update briRC backref info */
+        if (rc && !(p->flags & CONDFLAG_NOTMATCH)) {
+            ctx->briRC.source = input;
+            memcpy(ctx->briRC.regmatch, regmatch, sizeof(regmatch));
+        }
+        break;
+    }
+
+    if (p->flags & CONDFLAG_NOTMATCH) {
+        rc = !rc;
+    }
+
+    rewritelog((r, 4, ctx->perdir, "RewriteCond: input='%s' pattern='%s'%s "
+                "=> %s", input, p->pattern - p->pskip,
+                (p->flags & CONDFLAG_NOCASE) ? " [NC]" : "",
+                rc ? "matched" : "not-matched"));
+
+    return rc;
+}
+
+/* check for forced type and handler */
+static APR_INLINE void force_type_handler(rewriterule_entry *p,
+                                          rewrite_ctx *ctx)
+{
+    char *expanded;
+
+    if (p->forced_mimetype) {
+        expanded = do_expand(p->forced_mimetype, ctx, p);
+
+        if (*expanded) {
+            ap_str_tolower(expanded);
+
+            rewritelog((ctx->r, 2, ctx->perdir, "remember %s to have MIME-type "
+                        "'%s'", ctx->r->filename, expanded));
+
+            apr_table_setn(ctx->r->notes, REWRITE_FORCED_MIMETYPE_NOTEVAR,
+                           expanded);
+        }
+    }
+
+    if (p->forced_handler) {
+        expanded = do_expand(p->forced_handler, ctx, p);
+
+        if (*expanded) {
+            ap_str_tolower(expanded);
+
+            rewritelog((ctx->r, 2, ctx->perdir, "remember %s to have "
+                        "Content-handler '%s'", ctx->r->filename, expanded));
+
+            apr_table_setn(ctx->r->notes, REWRITE_FORCED_HANDLER_NOTEVAR,
+                           expanded);
+        }
+    }
+}
+
+/*
+ * Apply a single RewriteRule
+ */
+static int apply_rewrite_rule(rewriterule_entry *p, rewrite_ctx *ctx)
+{
+    ap_regmatch_t regmatch[AP_MAX_REG_MATCH];
+    apr_array_header_t *rewriteconds;
+    rewritecond_entry *conds;
+    int i, rc;
+    char *newuri = NULL;
+    request_rec *r = ctx->r;
+    int is_proxyreq = 0;
+
+    ctx->uri = r->filename;
+
+    if (ctx->perdir) {
+        apr_size_t dirlen = strlen(ctx->perdir);
+
+        /*
+         * Proxy request?
+         */
+        is_proxyreq = (   r->proxyreq && r->filename
+                       && !strncmp(r->filename, "proxy:", 6));
+
+        /* Since we want to match against the (so called) full URL, we have
+         * to re-add the PATH_INFO postfix
+         */
+        if (r->path_info && *r->path_info) {
+            rewritelog((r, 3, ctx->perdir, "add path info postfix: %s -> %s%s",
+                        ctx->uri, ctx->uri, r->path_info));
+            ctx->uri = apr_pstrcat(r->pool, ctx->uri, r->path_info, NULL);
+        }
+
+        /* Additionally we strip the physical path from the url to match
+         * it independent from the underlying filesystem.
+         */
+        if (!is_proxyreq && strlen(ctx->uri) >= dirlen &&
+            !strncmp(ctx->uri, ctx->perdir, dirlen)) {
+
+            rewritelog((r, 3, ctx->perdir, "strip per-dir prefix: %s -> %s",
+                        ctx->uri, ctx->uri + dirlen));
+            ctx->uri = ctx->uri + dirlen;
+        }
+    }
+
+    /* Try to match the URI against the RewriteRule pattern
+     * and exit immediately if it didn't apply.
+     */
+    rewritelog((r, 3, ctx->perdir, "applying pattern '%s' to uri '%s'",
+                p->pattern, ctx->uri));
+
+    rc = !ap_regexec(p->regexp, ctx->uri, AP_MAX_REG_MATCH, regmatch, 0);
+    if (! (( rc && !(p->flags & RULEFLAG_NOTMATCH)) ||
+           (!rc &&  (p->flags & RULEFLAG_NOTMATCH))   ) ) {
+        return 0;
+    }
+
+    /* It matched, wow! Now it's time to prepare the context structure for
+     * further processing
+     */
+    ctx->vary_this = NULL;
+    ctx->briRC.source = NULL;
+
+    if (p->flags & RULEFLAG_NOTMATCH) {
+        ctx->briRR.source = NULL;
+    }
+    else {
+        ctx->briRR.source = apr_pstrdup(r->pool, ctx->uri);
+        memcpy(ctx->briRR.regmatch, regmatch, sizeof(regmatch));
+    }
+
+    /* Ok, we already know the pattern has matched, but we now
+     * additionally have to check for all existing preconditions
+     * (RewriteCond) which have to be also true. We do this at
+     * this very late stage to avoid unnecessary checks which
+     * would slow down the rewriting engine.
+     */
+    rewriteconds = p->rewriteconds;
+    conds = (rewritecond_entry *)rewriteconds->elts;
+
+    for (i = 0; i < rewriteconds->nelts; ++i) {
+        rewritecond_entry *c = &conds[i];
+
+        rc = apply_rewrite_cond(c, ctx);
+        /*
+         * Reset vary_this if the novary flag is set for this condition.
+         */
+        if (c->flags & CONDFLAG_NOVARY) {
+            ctx->vary_this = NULL;
+        }
+        if (c->flags & CONDFLAG_ORNEXT) {
+            if (!rc) {
+                /* One condition is false, but another can be still true. */
+                ctx->vary_this = NULL;
+                continue;
+            }
+            else {
+                /* skip the rest of the chained OR conditions */
+                while (   i < rewriteconds->nelts
+                       && c->flags & CONDFLAG_ORNEXT) {
+                    c = &conds[++i];
+                }
+            }
+        }
+        else if (!rc) {
+            return 0;
+        }
+
+        /* If some HTTP header was involved in the condition, remember it
+         * for later use
+         */
+        if (ctx->vary_this) {
+            ctx->vary = ctx->vary
+                        ? apr_pstrcat(r->pool, ctx->vary, ", ", ctx->vary_this,
+                                      NULL)
+                        : ctx->vary_this;
+            ctx->vary_this = NULL;
+        }
+    }
+
+    /* expand the result */
+    if (!(p->flags & RULEFLAG_NOSUB)) {
+        newuri = do_expand(p->output, ctx, p);
+        rewritelog((r, 2, ctx->perdir, "rewrite '%s' -> '%s'", ctx->uri,
+                    newuri));
+    }
+
+    /* expand [E=var:val] and [CO=<cookie>] */
+    do_expand_env(p->env, ctx);
+    do_expand_cookie(p->cookie, ctx);
+
+    /* non-substitution rules ('RewriteRule <pat> -') end here. */
+    if (p->flags & RULEFLAG_NOSUB) {
+        force_type_handler(p, ctx);
+
+        if (p->flags & RULEFLAG_STATUS) {
+            rewritelog((r, 2, ctx->perdir, "forcing responsecode %d for %s",
+                        p->forced_responsecode, r->filename));
+
+            r->status = p->forced_responsecode;
+        }
+
+        return 2;
+    }
+
+    /* Now adjust API's knowledge about r->filename and r->args */
+    r->filename = newuri;
+
+    if (ctx->perdir && (p->flags & RULEFLAG_DISCARDPATHINFO)) {
+        r->path_info = NULL;
+    }
+
+    splitout_queryargs(r, p->flags);
+
+    /* Add the previously stripped per-directory location prefix, unless
+     * (1) it's an absolute URL path and
+     * (2) it's a full qualified URL
+     */
+    if (   ctx->perdir && !is_proxyreq && *r->filename != '/'
+        && !is_absolute_uri(r->filename, NULL)) {
+        rewritelog((r, 3, ctx->perdir, "add per-dir prefix: %s -> %s%s",
+                    r->filename, ctx->perdir, r->filename));
+
+        r->filename = apr_pstrcat(r->pool, ctx->perdir, r->filename, NULL);
+    }
+
+    /* If this rule is forced for proxy throughput
+     * (`RewriteRule ... ... [P]') then emulate mod_proxy's
+     * URL-to-filename handler to be sure mod_proxy is triggered
+     * for this URL later in the Apache API. But make sure it is
+     * a fully-qualified URL. (If not it is qualified with
+     * ourself).
+     */
+    if (p->flags & RULEFLAG_PROXY) {
+        /* For rules evaluated in server context, the mod_proxy fixup
+         * hook can be relied upon to escape the URI as and when
+         * necessary, since it occurs later.  If in directory context,
+         * the ordering of the fixup hooks is forced such that
+         * mod_proxy comes first, so the URI must be escaped here
+         * instead.  See PR 39746, 46428, and other headaches. */
+        if (ctx->perdir && (p->flags & RULEFLAG_NOESCAPE) == 0) {
+            char *old_filename = r->filename;
+
+            r->filename = ap_escape_uri(r->pool, r->filename);
+            rewritelog((r, 2, ctx->perdir, "escaped URI in per-dir context "
+                        "for proxy, %s -> %s", old_filename, r->filename));
+        }
+
+        fully_qualify_uri(r);
+
+        rewritelog((r, 2, ctx->perdir, "forcing proxy-throughput with %s",
+                    r->filename));
+
+        r->filename = apr_pstrcat(r->pool, "proxy:", r->filename, NULL);
+        return 1;
+    }
+
+    /* If this rule is explicitly forced for HTTP redirection
+     * (`RewriteRule .. .. [R]') then force an external HTTP
+     * redirect. But make sure it is a fully-qualified URL. (If
+     * not it is qualified with ourself).
+     */
+    if (p->flags & RULEFLAG_FORCEREDIRECT) {
+        fully_qualify_uri(r);
+
+        rewritelog((r, 2, ctx->perdir, "explicitly forcing redirect with %s",
+                    r->filename));
+
+        r->status = p->forced_responsecode;
+        return 1;
+    }
+
+    /* Special Rewriting Feature: Self-Reduction
+     * We reduce the URL by stripping a possible
+     * http[s]://<ourhost>[:<port>] prefix, i.e. a prefix which
+     * corresponds to ourself. This is to simplify rewrite maps
+     * and to avoid recursion, etc. When this prefix is not a
+     * coincidence then the user has to use [R] explicitly (see
+     * above).
+     */
+    reduce_uri(r);
+
+    /* If this rule is still implicitly forced for HTTP
+     * redirection (`RewriteRule .. <scheme>://...') then
+     * directly force an external HTTP redirect.
+     */
+    if (is_absolute_uri(r->filename, NULL)) {
+        rewritelog((r, 2, ctx->perdir, "implicitly forcing redirect (rc=%d) "
+                    "with %s", p->forced_responsecode, r->filename));
+
+        r->status = p->forced_responsecode;
+        return 1;
+    }
+
+    /* Finally remember the forced mime-type */
+    force_type_handler(p, ctx);
+
+    /* Puuhhhhhhhh... WHAT COMPLICATED STUFF ;_)
+     * But now we're done for this particular rule.
+     */
+    return 1;
+}
+
+/*
+ * Apply a complete rule set,
+ * i.e. a list of rewrite rules
+ */
+static int apply_rewrite_list(request_rec *r, apr_array_header_t *rewriterules,
+                              char *perdir)
+{
+    rewriterule_entry *entries;
+    rewriterule_entry *p;
+    int i;
+    int changed;
+    int rc;
+    int s;
+    rewrite_ctx *ctx;
+    int round = 1;
+
+    ctx = apr_palloc(r->pool, sizeof(*ctx));
+    ctx->perdir = perdir;
+    ctx->r = r;
+
+    /*
+     *  Iterate over all existing rules
+     */
+    entries = (rewriterule_entry *)rewriterules->elts;
+    changed = 0;
+    loop:
+    for (i = 0; i < rewriterules->nelts; i++) {
+        p = &entries[i];
+
+        /*
+         *  Ignore this rule on subrequests if we are explicitly
+         *  asked to do so or this is a proxy-throughput or a
+         *  forced redirect rule.
+         */
+        if (r->main != NULL &&
+            (p->flags & RULEFLAG_IGNOREONSUBREQ ||
+             p->flags & RULEFLAG_FORCEREDIRECT    )) {
+            continue;
+        }
+
+        /*
+         *  Apply the current rule.
+         */
+        ctx->vary = NULL;
+        rc = apply_rewrite_rule(p, ctx);
+
+        if (rc) {
+
+            /* Catch looping rules with pathinfo growing unbounded */
+            if ( strlen( r->filename ) > 2*r->server->limit_req_line ) {
+                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
+                              "RewriteRule '%s' and URI '%s' "
+                              "exceeded maximum length (%d)", 
+                              p->pattern, r->uri, 2*r->server->limit_req_line );
+                r->status = HTTP_INTERNAL_SERVER_ERROR;
+                return ACTION_STATUS;
+            }
+
+            /* Regardless of what we do next, we've found a match. Check to see
+             * if any of the request header fields were involved, and add them
+             * to the Vary field of the response.
+             */
+            if (ctx->vary) {
+                apr_table_merge(r->headers_out, "Vary", ctx->vary);
+            }
+
+            /*
+             * The rule sets the response code (implies match-only)
+             */
+            if (p->flags & RULEFLAG_STATUS) {
+                return ACTION_STATUS;
+            }
+
+            /*
+             * Indicate a change if this was not a match-only rule.
+             */
+            if (rc != 2) {
+                changed = ((p->flags & RULEFLAG_NOESCAPE)
+                           ? ACTION_NOESCAPE : ACTION_NORMAL);
+            }
+
+            /*
+             *  Pass-Through Feature (`RewriteRule .. .. [PT]'):
+             *  Because the Apache 1.x API is very limited we
+             *  need this hack to pass the rewritten URL to other
+             *  modules like mod_alias, mod_userdir, etc.
+             */
+            if (p->flags & RULEFLAG_PASSTHROUGH) {
+                rewritelog((r, 2, perdir, "forcing '%s' to get passed through "
+                           "to next API URI-to-filename handler", r->filename));
+                r->filename = apr_pstrcat(r->pool, "passthrough:",
+                                         r->filename, NULL);
+                changed = ACTION_NORMAL;
+                break;
+            }
+
+            if (p->flags & RULEFLAG_END) {
+                rewritelog((r, 8, perdir, "Rule has END flag, no further rewriting for this request"));
+                apr_pool_userdata_set("1", really_last_key, apr_pool_cleanup_null, r->pool);
+                break;
+            }
+            /*
+             *  Stop processing also on proxy pass-through and
+             *  last-rule and new-round flags.
+             */
+            if (p->flags & (RULEFLAG_PROXY | RULEFLAG_LASTRULE)) {
+                break;
+            }
+
+            /*
+             *  On "new-round" flag we just start from the top of
+             *  the rewriting ruleset again.
+             */
+            if (p->flags & RULEFLAG_NEWROUND) {
+                if (++round >= p->maxrounds) { 
+                    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02596)
+                                  "RewriteRule '%s' and URI '%s' exceeded "
+                                  "maximum number of rounds (%d) via the [N] flag", 
+                                  p->pattern, r->uri, p->maxrounds);
+
+                    r->status = HTTP_INTERNAL_SERVER_ERROR;
+                    return ACTION_STATUS; 
+                }
+                goto loop;
+            }
+
+            /*
+             *  If we are forced to skip N next rules, do it now.
+             */
+            if (p->skip > 0) {
+                s = p->skip;
+                while (   i < rewriterules->nelts
+                       && s > 0) {
+                    i++;
+                    s--;
+                }
+            }
+        }
+        else {
+            /*
+             *  If current rule is chained with next rule(s),
+             *  skip all this next rule(s)
+             */
+            while (   i < rewriterules->nelts
+                   && p->flags & RULEFLAG_CHAIN) {
+                i++;
+                p = &entries[i];
+            }
+        }
+    }
+    return changed;
+}
+
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |             Module Initialization Hooks
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+static int pre_config(apr_pool_t *pconf,
+                      apr_pool_t *plog,
+                      apr_pool_t *ptemp)
+{
+    APR_OPTIONAL_FN_TYPE(ap_register_rewrite_mapfunc) *map_pfn_register;
+
+    rewrite_lock_needed = 0; 
+    ap_mutex_register(pconf, rewritemap_mutex_type, NULL, APR_LOCK_DEFAULT, 0);
+
+    /* register int: rewritemap handlers */
+    map_pfn_register = APR_RETRIEVE_OPTIONAL_FN(ap_register_rewrite_mapfunc);
+    if (map_pfn_register) {
+        map_pfn_register("tolower", rewrite_mapfunc_tolower);
+        map_pfn_register("toupper", rewrite_mapfunc_toupper);
+        map_pfn_register("escape", rewrite_mapfunc_escape);
+        map_pfn_register("unescape", rewrite_mapfunc_unescape);
+    }
+    dbd_acquire = APR_RETRIEVE_OPTIONAL_FN(ap_dbd_acquire);
+    dbd_prepare = APR_RETRIEVE_OPTIONAL_FN(ap_dbd_prepare);
+    return OK;
+}
+
+static int post_config(apr_pool_t *p,
+                       apr_pool_t *plog,
+                       apr_pool_t *ptemp,
+                       server_rec *s)
+{
+    apr_status_t rv;
+
+    /* check if proxy module is available */
+    proxy_available = (ap_find_linked_module("mod_proxy.c") != NULL);
+
+    if (rewrite_lock_needed) {
+        rv = rewritelock_create(s, p);
+        if (rv != APR_SUCCESS) {
+            return HTTP_INTERNAL_SERVER_ERROR;
+        }
+
+        apr_pool_cleanup_register(p, (void *)s, rewritelock_remove,
+                apr_pool_cleanup_null);
+    }
+
+    /* if we are not doing the initial config, step through the servers and
+     * open the RewriteMap prg:xxx programs,
+     */
+    if (ap_state_query(AP_SQ_MAIN_STATE) == AP_SQ_MS_CREATE_CONFIG) {
+        for (; s; s = s->next) {
+            if (run_rewritemap_programs(s, p) != APR_SUCCESS) {
+                return HTTP_INTERNAL_SERVER_ERROR;
+            }
+        }
+    }
+
+    return OK;
+}
+
+static void init_child(apr_pool_t *p, server_rec *s)
+{
+    apr_status_t rv = 0; /* get a rid of gcc warning (REWRITELOG_DISABLED) */
+
+    if (rewrite_mapr_lock_acquire) {
+        rv = apr_global_mutex_child_init(&rewrite_mapr_lock_acquire,
+                 apr_global_mutex_lockfile(rewrite_mapr_lock_acquire), p);
+        if (rv != APR_SUCCESS) {
+            ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(00666)
+                         "mod_rewrite: could not init rewrite_mapr_lock_acquire"
+                         " in child");
+        }
+    }
+
+    /* create the lookup cache */
+    if (!init_cache(p)) {
+        ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(00667)
+                     "mod_rewrite: could not init map cache in child");
+    }
+}
+
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |                     runtime hooks
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+/*
+ * URI-to-filename hook
+ * [deals with RewriteRules in server context]
+ */
+static int hook_uri2file(request_rec *r)
+{
+    rewrite_perdir_conf *dconf;
+    rewrite_server_conf *conf;
+    const char *saved_rulestatus;
+    const char *var;
+    const char *thisserver;
+    char *thisport;
+    const char *thisurl;
+    unsigned int port;
+    int rulestatus;
+    void *skipdata;
+    const char *oargs;
+
+    /*
+     *  retrieve the config structures
+     */
+    conf = ap_get_module_config(r->server->module_config, &rewrite_module);
+
+    dconf = (rewrite_perdir_conf *)ap_get_module_config(r->per_dir_config,
+                                                        &rewrite_module);
+
+    /*
+     *  only do something under runtime if the engine is really enabled,
+     *  else return immediately!
+     */
+    if (!dconf || dconf->state == ENGINE_DISABLED) {
+        return DECLINED;
+    }
+
+    /*
+     *  check for the ugly API case of a virtual host section where no
+     *  mod_rewrite directives exists. In this situation we became no chance
+     *  by the API to setup our default per-server config so we have to
+     *  on-the-fly assume we have the default config. But because the default
+     *  config has a disabled rewriting engine we are lucky because can
+     *  just stop operating now.
+     */
+    if (conf->server != r->server) {
+        return DECLINED;
+    }
+
+    /* END flag was used as a RewriteRule flag on this request */
+    apr_pool_userdata_get(&skipdata, really_last_key, r->pool);
+    if (skipdata != NULL) {
+        rewritelog((r, 8, NULL, "Declining, no further rewriting due to END flag"));
+        return DECLINED;
+    }
+
+    /* Unless the anyuri option is set, ensure that the input to the
+     * first rule really is a URL-path, avoiding security issues with
+     * poorly configured rules.  See CVE-2011-3368, CVE-2011-4317. */
+    if ((dconf->options & OPTION_ANYURI) == 0
+        && ((r->unparsed_uri[0] == '*' && r->unparsed_uri[1] == '\0')
+            || !r->uri || r->uri[0] != '/')) {
+        rewritelog((r, 8, NULL, "Declining, request-URI '%s' is not a URL-path. "
+                    "Consult the manual entry for the RewriteOptions directive "
+                    "for options and caveats about matching other strings.",
+                    r->uri));
+        return DECLINED;
+    }
+
+    /*
+     *  remember the original query string for later check, since we don't
+     *  want to apply URL-escaping when no substitution has changed it.
+     */
+    oargs = r->args;
+
+    /*
+     *  add the SCRIPT_URL variable to the env. this is a bit complicated
+     *  due to the fact that apache uses subrequests and internal redirects
+     */
+
+    if (r->main == NULL) {
+         var = apr_table_get(r->subprocess_env, REDIRECT_ENVVAR_SCRIPT_URL);
+         if (var == NULL) {
+             apr_table_setn(r->subprocess_env, ENVVAR_SCRIPT_URL, r->uri);
+         }
+         else {
+             apr_table_setn(r->subprocess_env, ENVVAR_SCRIPT_URL, var);
+         }
+    }
+    else {
+         var = apr_table_get(r->main->subprocess_env, ENVVAR_SCRIPT_URL);
+         apr_table_setn(r->subprocess_env, ENVVAR_SCRIPT_URL, var);
+    }
+
+    /*
+     *  create the SCRIPT_URI variable for the env
+     */
+
+    /* add the canonical URI of this URL */
+    thisserver = ap_get_server_name_for_url(r);
+    port = ap_get_server_port(r);
+    if (ap_is_default_port(port, r)) {
+        thisport = "";
+    }
+    else {
+        thisport = apr_psprintf(r->pool, ":%u", port);
+    }
+    thisurl = apr_table_get(r->subprocess_env, ENVVAR_SCRIPT_URL);
+
+    /* set the variable */
+    var = apr_pstrcat(r->pool, ap_http_scheme(r), "://", thisserver, thisport,
+                      thisurl, NULL);
+    apr_table_setn(r->subprocess_env, ENVVAR_SCRIPT_URI, var);
+
+    if (!(saved_rulestatus = apr_table_get(r->notes,"mod_rewrite_rewritten"))) {
+        /* if filename was not initially set,
+         * we start with the requested URI
+         */
+        if (r->filename == NULL) {
+            r->filename = apr_pstrdup(r->pool, r->uri);
+            rewritelog((r, 2, NULL, "init rewrite engine with requested uri %s",
+                        r->filename));
+        }
+        else {
+            rewritelog((r, 2, NULL, "init rewrite engine with passed filename "
+                        "%s. Original uri = %s", r->filename, r->uri));
+        }
+
+        /*
+         *  now apply the rules ...
+         */
+        rulestatus = apply_rewrite_list(r, conf->rewriterules, NULL);
+        apr_table_setn(r->notes, "mod_rewrite_rewritten",
+                       apr_psprintf(r->pool,"%d",rulestatus));
+    }
+    else {
+        rewritelog((r, 2, NULL, "uri already rewritten. Status %s, Uri %s, "
+                    "r->filename %s", saved_rulestatus, r->uri, r->filename));
+
+        rulestatus = atoi(saved_rulestatus);
+    }
+
+    if (rulestatus) {
+        unsigned skip_absolute = is_absolute_uri(r->filename, NULL);
+        apr_size_t flen =  r->filename ? strlen(r->filename) : 0;
+        int to_proxyreq = (flen > 6 && strncmp(r->filename, "proxy:", 6) == 0);
+        int will_escape = skip_absolute && (rulestatus != ACTION_NOESCAPE);
+
+        if (r->args
+                && !will_escape
+                && *(ap_scan_vchar_obstext(r->args))) {
+            /*
+             * We have a raw control character or a ' ' in r->args.
+             * Correct encoding was missed.
+             * Correct encoding was missed and we're not going to escape
+             * it before returning.
+             */
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(10410)
+                          "Rewritten query string contains control "
+                          "characters or spaces");
+            return HTTP_FORBIDDEN;
+        }
+
+        if (ACTION_STATUS == rulestatus) {
+            int n = r->status;
+
+            r->status = HTTP_OK;
+            return n;
+        }
+
+        if (to_proxyreq) {
+            /* it should be go on as an internal proxy request */
+
+            /* check if the proxy module is enabled, so
+             * we can actually use it!
+             */
+            if (!proxy_available) {
+                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00669)
+                              "attempt to make remote request from mod_rewrite "
+                              "without proxy enabled: %s", r->filename);
+                return HTTP_FORBIDDEN;
+            }
+
+            if (rulestatus == ACTION_NOESCAPE) {
+                apr_table_setn(r->notes, "proxy-nocanon", "1");
+            }
+
+            /* make sure the QUERY_STRING and
+             * PATH_INFO parts get incorporated
+             */
+            if (r->path_info != NULL) {
+                r->filename = apr_pstrcat(r->pool, r->filename,
+                                          r->path_info, NULL);
+            }
+            if ((r->args != NULL)
+                && ((r->proxyreq == PROXYREQ_PROXY)
+                    || (rulestatus == ACTION_NOESCAPE))) {
+                /* see proxy_http:proxy_http_canon() */
+                r->filename = apr_pstrcat(r->pool, r->filename,
+                                          "?", r->args, NULL);
+            }
+
+            /* now make sure the request gets handled by the proxy handler */
+            if (PROXYREQ_NONE == r->proxyreq) {
+                r->proxyreq = PROXYREQ_REVERSE;
+            }
+            r->handler  = "proxy-server";
+
+            rewritelog((r, 1, NULL, "go-ahead with proxy request %s [OK]",
+                        r->filename));
+            return OK;
+        }
+        else if (skip_absolute > 0) {
+            int n;
+
+            /* it was finally rewritten to a remote URL */
+
+            if (rulestatus != ACTION_NOESCAPE) {
+                rewritelog((r, 1, NULL, "escaping %s for redirect",
+                            r->filename));
+                r->filename = escape_absolute_uri(r->pool, r->filename, skip_absolute);
+            }
+
+            /* append the QUERY_STRING part */
+            if (r->args) {
+                char *escaped_args = NULL;
+                int noescape = (rulestatus == ACTION_NOESCAPE ||
+                                (oargs && !strcmp(r->args, oargs)));
+
+                r->filename = apr_pstrcat(r->pool, r->filename, "?",
+                                          noescape
+                                            ? r->args
+                                            : (escaped_args =
+                                               ap_escape_uri(r->pool, r->args)),
+                                          NULL);
+
+                rewritelog((r, 1, NULL, "%s %s to query string for redirect %s",
+                            noescape ? "copying" : "escaping",
+                            r->args ,
+                            noescape ? "" : escaped_args));
+            }
+
+            /* determine HTTP redirect response code */
+            if (ap_is_HTTP_REDIRECT(r->status)) {
+                n = r->status;
+                r->status = HTTP_OK; /* make Apache kernel happy */
+            }
+            else {
+                n = HTTP_MOVED_TEMPORARILY;
+            }
+
+            /* now do the redirection */
+            apr_table_setn(r->headers_out, "Location", r->filename);
+            rewritelog((r, 1, NULL, "redirect to %s [REDIRECT/%d]", r->filename,
+                        n));
+
+            return n;
+        }
+        else if (flen > 12 && strncmp(r->filename, "passthrough:", 12) == 0) {
+            /*
+             * Hack because of underpowered API: passing the current
+             * rewritten filename through to other URL-to-filename handlers
+             * just as it were the requested URL. This is to enable
+             * post-processing by mod_alias, etc.  which always act on
+             * r->uri! The difference here is: We do not try to
+             * add the document root
+             */
+            r->uri = apr_pstrdup(r->pool, r->filename+12);
+            return DECLINED;
+        }
+        else {
+            /* it was finally rewritten to a local path */
+            const char *uri_reduced = NULL;
+
+            /* expand "/~user" prefix */
+#if APR_HAS_USER
+            r->filename = expand_tildepaths(r, r->filename);
+#endif
+            rewritelog((r, 2, NULL, "local path result: %s", r->filename));
+
+            /* the filename must be either an absolute local path or an
+             * absolute local URL.
+             */
+            if (   *r->filename != '/'
+                && !ap_os_is_path_absolute(r->pool, r->filename)) {
+                return HTTP_BAD_REQUEST;
+            }
+
+            /* if there is no valid prefix, we call
+             * the translator from the core and
+             * prefix the filename with document_root
+             *
+             * NOTICE:
+             * We cannot leave out the prefix_stat because
+             * - when we always prefix with document_root
+             *   then no absolute path can be created, e.g. via
+             *   emulating a ScriptAlias directive, etc.
+             * - when we always NOT prefix with document_root
+             *   then the files under document_root have to
+             *   be references directly and document_root
+             *   gets never used and will be a dummy parameter -
+             *   this is also bad
+             *
+             * BUT:
+             * Under real Unix systems this is no problem,
+             * because we only do stat() on the first directory
+             * and this gets cached by the kernel for along time!
+             */
+
+            if(!(conf->options & OPTION_LEGACY_PREFIX_DOCROOT)) {
+                uri_reduced = apr_table_get(r->notes, "mod_rewrite_uri_reduced");
+            }
+
+            if (!prefix_stat(r->filename, r->pool) || uri_reduced != NULL) {
+                int res;
+                char *tmp = r->uri;
+
+                r->uri = r->filename;
+                res = ap_core_translate(r);
+                r->uri = tmp;
+
+                if (res != OK) {
+                    rewritelog((r, 1, NULL, "prefixing with document_root of %s"
+                                " FAILED", r->filename));
+
+                    return res;
+                }
+
+                rewritelog((r, 2, NULL, "prefixed with document_root to %s",
+                            r->filename));
+            }
+
+            rewritelog((r, 1, NULL, "go-ahead with %s [OK]", r->filename));
+            return OK;
+        }
+    }
+    else {
+        rewritelog((r, 1, NULL, "pass through %s", r->filename));
+        return DECLINED;
+    }
+}
+
+/*
+ * Fixup hook
+ * [RewriteRules in directory context]
+ */
+static int hook_fixup(request_rec *r)
+{
+    rewrite_perdir_conf *dconf;
+    char *cp;
+    char *cp2;
+    const char *ccp;
+    apr_size_t l;
+    int rulestatus;
+    int n;
+    char *ofilename, *oargs;
+    int is_proxyreq;
+    void *skipdata;
+
+    dconf = (rewrite_perdir_conf *)ap_get_module_config(r->per_dir_config,
+                                                        &rewrite_module);
+
+    /* if there is no per-dir config we return immediately */
+    if (dconf == NULL) {
+        return DECLINED;
+    }
+
+    /*
+     * only do something under runtime if the engine is really enabled,
+     * for this directory, else return immediately!
+     */
+    if (dconf->state == ENGINE_DISABLED) {
+        return DECLINED;
+    }
+
+    /* if there are no real (i.e. no RewriteRule directives!)
+       per-dir config of us, we return also immediately */
+    if (dconf->directory == NULL) {
+        return DECLINED;
+    }
+
+    /*
+     * Proxy request?
+     */
+    is_proxyreq = (   r->proxyreq && r->filename
+                   && !strncmp(r->filename, "proxy:", 6));
+
+    /*
+     *  .htaccess file is called before really entering the directory, i.e.:
+     *  URL: http://localhost/foo  and .htaccess is located in foo directory
+     *  Ignore such attempts, allowing mod_dir to direct the client to the
+     *  canonical URL. This can be controlled with the AllowNoSlash option.
+     */
+    if (!is_proxyreq && !(dconf->options & OPTION_NOSLASH)) {
+        l = strlen(dconf->directory) - 1;
+        if (r->filename && strlen(r->filename) == l &&
+            (dconf->directory)[l] == '/' &&
+            !strncmp(r->filename, dconf->directory, l)) {
+            return DECLINED;
+        }
+    }
+
+    /* END flag was used as a RewriteRule flag on this request */
+    apr_pool_userdata_get(&skipdata, really_last_key, r->pool);
+    if (skipdata != NULL) {
+        rewritelog((r, 8, dconf->directory, "Declining, no further rewriting due to END flag"));
+        return DECLINED;
+    }
+
+    /*
+     *  Do the Options check after engine check, so
+     *  the user is able to explicitly turn RewriteEngine Off.
+     */
+    if (!(ap_allow_options(r) & (OPT_SYM_LINKS | OPT_SYM_OWNER))) {
+        /* FollowSymLinks is mandatory! */
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00670)
+                     "Options FollowSymLinks and SymLinksIfOwnerMatch are both off, "
+                     "so the RewriteRule directive is also forbidden "
+                     "due to its similar ability to circumvent directory restrictions : "
+                     "%s", r->filename);
+        return HTTP_FORBIDDEN;
+    }
+
+    /*
+     *  remember the current filename before rewriting for later check
+     *  to prevent deadlooping because of internal redirects
+     *  on final URL/filename which can be equal to the initial one.
+     *  also, we'll restore original r->filename if we decline this
+     *  request
+     */
+    ofilename = r->filename;
+    oargs = r->args;
+
+    if (r->filename == NULL) {
+        r->filename = apr_pstrdup(r->pool, r->uri);
+        rewritelog((r, 2, dconf->directory, "init rewrite engine with"
+                   " requested uri %s", r->filename));
+    }
+
+    /*
+     *  now apply the rules ...
+     */
+    rulestatus = apply_rewrite_list(r, dconf->rewriterules, dconf->directory);
+    if (rulestatus) {
+        unsigned skip_absolute = is_absolute_uri(r->filename, NULL);
+        int to_proxyreq = 0;
+        int will_escape = 0;
+
+        l = strlen(r->filename);
+        to_proxyreq = l > 6 && strncmp(r->filename, "proxy:", 6) == 0;
+        will_escape = skip_absolute && (rulestatus != ACTION_NOESCAPE);
+
+        if (r->args
+               && !will_escape
+               &&  *(ap_scan_vchar_obstext(r->args))) {
+            /*
+             * We have a raw control character or a ' ' in r->args.
+             * Correct encoding was missed.
+             */
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(10411)
+                          "Rewritten query string contains control "
+                          "characters or spaces");
+            return HTTP_FORBIDDEN;
+        }
+
+        if (ACTION_STATUS == rulestatus) {
+            int n = r->status;
+
+            r->status = HTTP_OK;
+            return n;
+        }
+
+        if (to_proxyreq) {
+            /* it should go on as an internal proxy request */
+
+            /* make sure the QUERY_STRING and
+             * PATH_INFO parts get incorporated
+             * (r->path_info was already appended by the
+             * rewriting engine because of the per-dir context!)
+             */
+            if (r->args != NULL) {
+                /* see proxy_http:proxy_http_canon() */
+                r->filename = apr_pstrcat(r->pool, r->filename,
+                                          "?", r->args, NULL);
+            }
+
+            /* now make sure the request gets handled by the proxy handler */
+            if (PROXYREQ_NONE == r->proxyreq) {
+                r->proxyreq = PROXYREQ_REVERSE;
+            }
+            r->handler  = "proxy-server";
+
+            rewritelog((r, 1, dconf->directory, "go-ahead with proxy request "
+                        "%s [OK]", r->filename));
+            return OK;
+        }
+        else if (skip_absolute > 0) {
+            /* it was finally rewritten to a remote URL */
+
+            /* because we are in a per-dir context
+             * first try to replace the directory with its base-URL
+             * if there is a base-URL available
+             */
+            if (dconf->baseurl != NULL) {
+                /* skip 'scheme://' */
+                cp = r->filename + skip_absolute;
+
+                if ((cp = ap_strchr(cp, '/')) != NULL && *(++cp)) {
+                    rewritelog((r, 2, dconf->directory,
+                                "trying to replace prefix %s with %s",
+                                dconf->directory, dconf->baseurl));
+
+                    /* I think, that hack needs an explanation:
+                     * well, here is it:
+                     * mod_rewrite was written for unix systems, were
+                     * absolute file-system paths start with a slash.
+                     * URL-paths _also_ start with slashes, so they
+                     * can be easily compared with system paths.
+                     *
+                     * the following assumes, that the actual url-path
+                     * may be prefixed by the current directory path and
+                     * tries to replace the system path with the RewriteBase
+                     * URL.
+                     * That assumption is true if we use a RewriteRule like
+                     *
+                     * RewriteRule ^foo bar [R]
+                     *
+                     * (see apply_rewrite_rule function)
+                     * However on systems that don't have a / as system
+                     * root this will never match, so we skip the / after the
+                     * hostname and compare/substitute only the stuff after it.
+                     *
+                     * (note that cp was already increased to the right value)
+                     */
+                    cp2 = subst_prefix_path(r, cp, (*dconf->directory == '/')
+                                                   ? dconf->directory + 1
+                                                   : dconf->directory,
+                                            dconf->baseurl + 1);
+                    if (strcmp(cp2, cp) != 0) {
+                        *cp = '\0';
+                        r->filename = apr_pstrcat(r->pool, r->filename,
+                                                  cp2, NULL);
+                    }
+                }
+            }
+
+            /* now prepare the redirect... */
+            if (rulestatus != ACTION_NOESCAPE) {
+                rewritelog((r, 1, dconf->directory, "escaping %s for redirect",
+                            r->filename));
+                r->filename = escape_absolute_uri(r->pool, r->filename, skip_absolute);
+            }
+
+            /* append the QUERY_STRING part */
+            if (r->args) {
+                char *escaped_args = NULL;
+                int noescape = (rulestatus == ACTION_NOESCAPE ||
+                                (oargs && !strcmp(r->args, oargs)));
+
+                r->filename = apr_pstrcat(r->pool, r->filename, "?",
+                                          noescape
+                                            ? r->args
+                                            : (escaped_args = ap_escape_uri(r->pool, r->args)),
+                                          NULL);
+
+                rewritelog((r, 1, dconf->directory, "%s %s to query string for redirect %s",
+                            noescape ? "copying" : "escaping",
+                            r->args ,
+                            noescape ? "" : escaped_args));
+            }
+
+            /* determine HTTP redirect response code */
+            if (ap_is_HTTP_REDIRECT(r->status)) {
+                n = r->status;
+                r->status = HTTP_OK; /* make Apache kernel happy */
+            }
+            else {
+                n = HTTP_MOVED_TEMPORARILY;
+            }
+
+            /* now do the redirection */
+            apr_table_setn(r->headers_out, "Location", r->filename);
+            rewritelog((r, 1, dconf->directory, "redirect to %s [REDIRECT/%d]",
+                        r->filename, n));
+            return n;
+        }
+        else {
+            const char *tmpfilename = NULL;
+            /* it was finally rewritten to a local path */
+
+            /* if someone used the PASSTHROUGH flag in per-dir
+             * context we just ignore it. It is only useful
+             * in per-server context
+             */
+            if (l > 12 && strncmp(r->filename, "passthrough:", 12) == 0) {
+                r->filename = apr_pstrdup(r->pool, r->filename+12);
+            }
+
+            /* the filename must be either an absolute local path or an
+             * absolute local URL.
+             */
+            if (   *r->filename != '/'
+                && !ap_os_is_path_absolute(r->pool, r->filename)) {
+                return HTTP_BAD_REQUEST;
+            }
+
+            /* Check for deadlooping:
+             * At this point we KNOW that at least one rewriting
+             * rule was applied, but when the resulting URL is
+             * the same as the initial URL, we are not allowed to
+             * use the following internal redirection stuff because
+             * this would lead to a deadloop.
+             */
+            if (ofilename != NULL && strcmp(r->filename, ofilename) == 0) {
+                rewritelog((r, 1, dconf->directory, "initial URL equal rewritten"
+                            " URL: %s [IGNORING REWRITE]", r->filename));
+                return OK;
+            }
+
+            tmpfilename = r->filename;
+
+            /* if there is a valid base-URL then substitute
+             * the per-dir prefix with this base-URL if the
+             * current filename still is inside this per-dir
+             * context. If not then treat the result as a
+             * plain URL
+             */
+            if (dconf->baseurl != NULL) {
+                rewritelog((r, 2, dconf->directory, "trying to replace prefix "
+                            "%s with %s", dconf->directory, dconf->baseurl));
+
+                r->filename = subst_prefix_path(r, r->filename,
+                                                dconf->directory,
+                                                dconf->baseurl);
+            }
+            else {
+                /* if no explicit base-URL exists we assume
+                 * that the directory prefix is also a valid URL
+                 * for this webserver and only try to remove the
+                 * document_root if it is prefix
+                 */
+                if ((ccp = ap_document_root(r)) != NULL) {
+                    /* strip trailing slash */
+                    l = strlen(ccp);
+                    if (ccp[l-1] == '/') {
+                        --l;
+                    }
+                    if (!strncmp(r->filename, ccp, l) &&
+                        r->filename[l] == '/') {
+                        rewritelog((r, 2,dconf->directory, "strip document_root"
+                                    " prefix: %s -> %s", r->filename,
+                                    r->filename+l));
+
+                        r->filename = apr_pstrdup(r->pool, r->filename+l);
+                    }
+                }
+            }
+
+            /* No base URL, or r->filename wasn't still under dconf->directory
+             * or, r->filename wasn't still under the document root. 
+             * If there's a context document root AND a context prefix, and 
+             * the context document root is a prefix of r->filename, replace.
+             * This allows a relative substitution on a path found by mod_userdir 
+             * or mod_alias without baking in a RewriteBase.
+             */
+            if (tmpfilename == r->filename && 
+                !(dconf->options & OPTION_IGNORE_CONTEXT_INFO)) { 
+                if ((ccp = ap_context_document_root(r)) != NULL) { 
+                    const char *prefix = ap_context_prefix(r);
+                    if (prefix != NULL) { 
+                        rewritelog((r, 2, dconf->directory, "trying to replace "
+                                    "context docroot %s with context prefix %s",
+                                    ccp, prefix));
+                        r->filename = subst_prefix_path(r, r->filename,
+                                ccp, prefix);
+                    }
+                }
+            }
+
+            apr_table_setn(r->notes, "redirect-keeps-vary", "");
+
+            /* now initiate the internal redirect */
+            rewritelog((r, 1, dconf->directory, "internal redirect with %s "
+                        "[INTERNAL REDIRECT]", r->filename));
+            r->filename = apr_pstrcat(r->pool, "redirect:", r->filename, NULL);
+            r->handler = REWRITE_REDIRECT_HANDLER_NAME;
+            return OK;
+        }
+    }
+    else {
+        rewritelog((r, 1, dconf->directory, "pass through %s", r->filename));
+        r->filename = ofilename;
+        return DECLINED;
+    }
+}
+
+/*
+ * MIME-type hook
+ * [T=...,H=...] execution
+ */
+static int hook_mimetype(request_rec *r)
+{
+    const char *t;
+
+    /* type */
+    t = apr_table_get(r->notes, REWRITE_FORCED_MIMETYPE_NOTEVAR);
+    if (t && *t) {
+        rewritelog((r, 1, NULL, "force filename %s to have MIME-type '%s'",
+                    r->filename, t));
+
+        ap_set_content_type(r, t);
+    }
+
+    /* handler */
+    t = apr_table_get(r->notes, REWRITE_FORCED_HANDLER_NOTEVAR);
+    if (t && *t) {
+        rewritelog((r, 1, NULL, "force filename %s to have the "
+                    "Content-handler '%s'", r->filename, t));
+
+        r->handler = t;
+    }
+
+    return OK;
+}
+
+
+/*
+ * "content" handler for internal redirects
+ */
+static int handler_redirect(request_rec *r)
+{
+    if (strcmp(r->handler, REWRITE_REDIRECT_HANDLER_NAME)) {
+        return DECLINED;
+    }
+
+    /* just make sure that we are really meant! */
+    if (strncmp(r->filename, "redirect:", 9) != 0) {
+        return DECLINED;
+    }
+
+    /* now do the internal redirect */
+    ap_internal_redirect(apr_pstrcat(r->pool, r->filename+9,
+                                     r->args ? "?" : NULL, r->args, NULL), r);
+
+    /* and return gracefully */
+    return OK;
+}
+
+
+/*
+ * +-------------------------------------------------------+
+ * |                                                       |
+ * |                Module paraphernalia
+ * |                                                       |
+ * +-------------------------------------------------------+
+ */
+
+static const command_rec command_table[] = {
+    AP_INIT_FLAG(    "RewriteEngine",   cmd_rewriteengine,  NULL, OR_FILEINFO,
+                     "On or Off to enable or disable (default) the whole "
+                     "rewriting engine"),
+    AP_INIT_ITERATE( "RewriteOptions",  cmd_rewriteoptions,  NULL, OR_FILEINFO,
+                     "List of option strings to set"),
+    AP_INIT_TAKE1(   "RewriteBase",     cmd_rewritebase,     NULL, OR_FILEINFO,
+                     "the base URL of the per-directory context"),
+    AP_INIT_RAW_ARGS("RewriteCond",     cmd_rewritecond,     NULL, OR_FILEINFO,
+                     "an input string and a to be applied regexp-pattern"),
+    AP_INIT_RAW_ARGS("RewriteRule",     cmd_rewriterule,     NULL, OR_FILEINFO,
+                     "an URL-applied regexp-pattern and a substitution URL"),
+    AP_INIT_TAKE23(   "RewriteMap",      cmd_rewritemap,      NULL, RSRC_CONF,
+                     "a mapname and a filename and options"),
+    { NULL }
+};
+
+static void ap_register_rewrite_mapfunc(char *name, rewrite_mapfunc_t *func)
+{
+    apr_hash_set(mapfunc_hash, name, strlen(name), (const void *)func);
+}
+
+static void register_hooks(apr_pool_t *p)
+{
+    /* fixup after mod_proxy, so that the proxied url will not
+     * escaped accidentally by mod_proxy's fixup.
+     */
+    static const char * const aszPre[]={ "mod_proxy.c", NULL };
+
+    /* make the hashtable before registering the function, so that
+     * other modules are prevented from accessing uninitialized memory.
+     */
+    mapfunc_hash = apr_hash_make(p);
+    APR_REGISTER_OPTIONAL_FN(ap_register_rewrite_mapfunc);
+
+    ap_hook_handler(handler_redirect, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_pre_config(pre_config, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_post_config(post_config, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_child_init(init_child, NULL, NULL, APR_HOOK_MIDDLE);
+
+    ap_hook_fixups(hook_fixup, aszPre, NULL, APR_HOOK_FIRST);
+    ap_hook_fixups(hook_mimetype, NULL, NULL, APR_HOOK_LAST);
+    ap_hook_translate_name(hook_uri2file, NULL, NULL, APR_HOOK_FIRST);
+}
+
+    /* the main config structure */
+AP_DECLARE_MODULE(rewrite) = {
+   STANDARD20_MODULE_STUFF,
+   config_perdir_create,        /* create per-dir    config structures */
+   config_perdir_merge,         /* merge  per-dir    config structures */
+   config_server_create,        /* create per-server config structures */
+   config_server_merge,         /* merge  per-server config structures */
+   command_table,               /* table of config file commands       */
+   register_hooks               /* register hooks                      */
+};
+
+/*EOF*/