Adding upstream version 3:4.8.30.upstream/3%4.8.30

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

1 files changed, 1121 insertions, 0 deletions

diff --git a/lib/search/regex.c b/lib/search/regex.c
new file mode 100644
index 0000000..d24cf48
--- /dev/null
+++ b/lib/search/regex.c
@@ -0,0 +1,1121 @@
+/*
+   Search text engine.
+   Regex search
+
+   Copyright (C) 2009-2023
+   Free Software Foundation, Inc.
+
+   Written by:
+   Slava Zanko <slavazanko@gmail.com>, 2009, 2010, 2011, 2013
+   Vitaliy Filippov <vitalif@yourcmc.ru>, 2011
+   Andrew Borodin <aborodin@vmail.ru>, 2013-2015
+
+   This file is part of the Midnight Commander.
+
+   The Midnight Commander is free software: you can redistribute it
+   and/or modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation, either version 3 of the License,
+   or (at your option) any later version.
+
+   The Midnight Commander is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+
+#include <stdlib.h>
+
+#include "lib/global.h"
+#include "lib/strutil.h"
+#include "lib/search.h"
+#include "lib/strescape.h"
+#include "lib/util.h"           /* MC_PTR_FREE */
+
+#include "internal.h"
+
+/*** global variables ****************************************************************************/
+
+/*** file scope macro definitions ****************************************************************/
+
+#define REPLACE_PREPARE_T_NOTHING_SPECIAL -1
+#define REPLACE_PREPARE_T_REPLACE_FLAG    -2
+#define REPLACE_PREPARE_T_ESCAPE_SEQ      -3
+
+/*** file scope type declarations ****************************************************************/
+
+typedef enum
+{
+    REPLACE_T_NO_TRANSFORM = 0,
+    REPLACE_T_UPP_TRANSFORM_CHAR = 1,
+    REPLACE_T_LOW_TRANSFORM_CHAR = 2,
+    REPLACE_T_UPP_TRANSFORM = 4,
+    REPLACE_T_LOW_TRANSFORM = 8
+} replace_transform_type_t;
+
+/*** forward declarations (file scope functions) *************************************************/
+
+/*** file scope variables ************************************************************************/
+
+/* --------------------------------------------------------------------------------------------- */
+/*** file scope functions ************************************************************************/
+/* --------------------------------------------------------------------------------------------- */
+
+static gboolean
+mc_search__regex_str_append_if_special (GString * copy_to, const GString * regex_str,
+                                        gsize * offset)
+{
+    const char *special_chars[] = {
+        "\\s", "\\S",
+        "\\d", "\\D",
+        "\\b", "\\B",
+        "\\w", "\\W",
+        "\\t", "\\n",
+        "\\r", "\\f",
+        "\\a", "\\e",
+        "\\x", "\\X",
+        "\\c", "\\C",
+        "\\l", "\\L",
+        "\\u", "\\U",
+        "\\E", "\\Q",
+        NULL
+    };
+
+    char *tmp_regex_str;
+    const char **spec_chr;
+
+    tmp_regex_str = &(regex_str->str[*offset]);
+
+    for (spec_chr = special_chars; *spec_chr != NULL; spec_chr++)
+    {
+        gsize spec_chr_len;
+
+        spec_chr_len = strlen (*spec_chr);
+
+        if (strncmp (tmp_regex_str, *spec_chr, spec_chr_len) == 0
+            && !strutils_is_char_escaped (regex_str->str, tmp_regex_str))
+        {
+            if (strncmp ("\\x", *spec_chr, spec_chr_len) == 0)
+            {
+                if (tmp_regex_str[spec_chr_len] != '{')
+                    spec_chr_len += 2;
+                else
+                {
+                    while ((spec_chr_len < regex_str->len - *offset)
+                           && tmp_regex_str[spec_chr_len] != '}')
+                        spec_chr_len++;
+                    if (tmp_regex_str[spec_chr_len] == '}')
+                        spec_chr_len++;
+                }
+            }
+            g_string_append_len (copy_to, tmp_regex_str, spec_chr_len);
+            *offset += spec_chr_len;
+            return TRUE;
+        }
+    }
+
+    return FALSE;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static void
+mc_search__cond_struct_new_regex_hex_add (const char *charset, GString * str_to,
+                                          const GString * one_char)
+{
+    GString *upp, *low;
+    gsize loop;
+
+    upp = mc_search__toupper_case_str (charset, one_char);
+    low = mc_search__tolower_case_str (charset, one_char);
+
+    for (loop = 0; loop < upp->len; loop++)
+    {
+        gchar tmp_str[10 + 1];  /* longest content is "[\\x%02X\\x%02X]" */
+        gint tmp_len;
+
+        if (loop >= low->len || upp->str[loop] == low->str[loop])
+            tmp_len =
+                g_snprintf (tmp_str, sizeof (tmp_str), "\\x%02X", (unsigned char) upp->str[loop]);
+        else
+            tmp_len =
+                g_snprintf (tmp_str, sizeof (tmp_str), "[\\x%02X\\x%02X]",
+                            (unsigned char) upp->str[loop], (unsigned char) low->str[loop]);
+
+        g_string_append_len (str_to, tmp_str, tmp_len);
+    }
+
+    g_string_free (upp, TRUE);
+    g_string_free (low, TRUE);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static void
+mc_search__cond_struct_new_regex_accum_append (const char *charset, GString * str_to,
+                                               GString * str_from)
+{
+    GString *recoded_part;
+    gsize loop = 0;
+
+    recoded_part = g_string_sized_new (32);
+
+    while (loop < str_from->len)
+    {
+        GString *one_char;
+        gboolean just_letters;
+
+        one_char =
+            mc_search__get_one_symbol (charset, str_from->str + loop,
+                                       MIN (str_from->len - loop, 6), &just_letters);
+
+        if (one_char->len == 0)
+            loop++;
+        else
+        {
+            loop += one_char->len;
+
+            if (just_letters)
+                mc_search__cond_struct_new_regex_hex_add (charset, recoded_part, one_char);
+            else
+                g_string_append_len (recoded_part, one_char->str, one_char->len);
+        }
+
+        g_string_free (one_char, TRUE);
+    }
+
+    g_string_append_len (str_to, recoded_part->str, recoded_part->len);
+    g_string_free (recoded_part, TRUE);
+    g_string_set_size (str_from, 0);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+/**
+ * Creates a case-insensitive version of a regex pattern.
+ *
+ * For example (assuming ASCII charset): given "\\bHello!\\xAB", returns
+ * "\\b[Hh][Ee][Ll][Ll][Oo]!\\xAB" (this example is for easier reading; in
+ * reality hex codes are used instead of letters).
+ *
+ * This function knows not to ruin special regex symbols.
+ *
+ * This function is used when working with non-UTF-8 charsets: GLib's
+ * regex engine doesn't understand such charsets and therefore can't do
+ * this job itself.
+ */
+static GString *
+mc_search__cond_struct_new_regex_ci_str (const char *charset, const GString * astr)
+{
+    GString *accumulator, *spec_char, *ret_str;
+    gsize loop;
+
+    ret_str = g_string_sized_new (64);
+    accumulator = g_string_sized_new (64);
+    spec_char = g_string_sized_new (64);
+    loop = 0;
+
+    while (loop < astr->len)
+    {
+        if (mc_search__regex_str_append_if_special (spec_char, astr, &loop))
+        {
+            mc_search__cond_struct_new_regex_accum_append (charset, ret_str, accumulator);
+            g_string_append_len (ret_str, spec_char->str, spec_char->len);
+            g_string_set_size (spec_char, 0);
+            continue;
+        }
+
+        if (astr->str[loop] == '[' && !strutils_is_char_escaped (astr->str, &(astr->str[loop])))
+        {
+            mc_search__cond_struct_new_regex_accum_append (charset, ret_str, accumulator);
+
+            while (loop < astr->len && !(astr->str[loop] == ']'
+                                         && !strutils_is_char_escaped (astr->str,
+                                                                       &(astr->str[loop]))))
+            {
+                g_string_append_c (ret_str, astr->str[loop]);
+                loop++;
+            }
+
+            g_string_append_c (ret_str, astr->str[loop]);
+            loop++;
+            continue;
+        }
+        /*
+           TODO: handle [ and ]
+         */
+        g_string_append_c (accumulator, astr->str[loop]);
+        loop++;
+    }
+    mc_search__cond_struct_new_regex_accum_append (charset, ret_str, accumulator);
+
+    g_string_free (accumulator, TRUE);
+    g_string_free (spec_char, TRUE);
+
+    return ret_str;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+#ifdef SEARCH_TYPE_GLIB
+/* A thin wrapper above g_regex_match_full that makes sure the string passed
+ * to it is valid UTF-8 (unless G_REGEX_RAW compile flag was set), as it is a
+ * requirement by glib and it might crash otherwise. See: mc ticket 3449.
+ * Be careful: there might be embedded NULs in the strings. */
+static gboolean
+mc_search__g_regex_match_full_safe (const GRegex * regex,
+                                    const gchar * string,
+                                    gssize string_len,
+                                    gint start_position,
+                                    GRegexMatchFlags match_options,
+                                    GMatchInfo ** match_info, GError ** error)
+{
+    char *string_safe, *p, *end;
+    gboolean ret;
+
+    if (string_len < 0)
+        string_len = strlen (string);
+
+    if ((g_regex_get_compile_flags (regex) & G_REGEX_RAW)
+        || g_utf8_validate (string, string_len, NULL))
+    {
+        return g_regex_match_full (regex, string, string_len, start_position, match_options,
+                                   match_info, error);
+    }
+
+    /* Correctly handle embedded NULs while copying */
+    p = string_safe = g_malloc (string_len + 1);
+    memcpy (string_safe, string, string_len);
+    string_safe[string_len] = '\0';
+    end = p + string_len;
+
+    while (p < end)
+    {
+        gunichar c = g_utf8_get_char_validated (p, -1);
+        if (c != (gunichar) (-1) && c != (gunichar) (-2))
+        {
+            p = g_utf8_next_char (p);
+        }
+        else
+        {
+            /* U+FFFD would be the proper choice, but then we'd have to
+               maintain mapping between old and new offsets.
+               So rather do a byte by byte replacement. */
+            *p++ = '\0';
+        }
+    }
+
+    ret =
+        g_regex_match_full (regex, string_safe, string_len, start_position, match_options,
+                            match_info, error);
+    g_free (string_safe);
+    return ret;
+}
+#endif /* SEARCH_TYPE_GLIB */
+
+/* --------------------------------------------------------------------------------------------- */
+
+static mc_search__found_cond_t
+mc_search__regex_found_cond_one (mc_search_t * lc_mc_search, mc_search_regex_t * regex,
+                                 GString * search_str)
+{
+#ifdef SEARCH_TYPE_GLIB
+    GError *mcerror = NULL;
+
+    if (!mc_search__g_regex_match_full_safe
+        (regex, search_str->str, search_str->len, 0, G_REGEX_MATCH_NEWLINE_ANY,
+         &lc_mc_search->regex_match_info, &mcerror))
+    {
+        g_match_info_free (lc_mc_search->regex_match_info);
+        lc_mc_search->regex_match_info = NULL;
+        if (mcerror != NULL)
+        {
+            lc_mc_search->error = MC_SEARCH_E_REGEX;
+            g_free (lc_mc_search->error_str);
+            lc_mc_search->error_str =
+                str_conv_gerror_message (mcerror, _("Regular expression error"));
+            g_error_free (mcerror);
+            return COND__FOUND_ERROR;
+        }
+        return COND__NOT_FOUND;
+    }
+    lc_mc_search->num_results = g_match_info_get_match_count (lc_mc_search->regex_match_info);
+#else /* SEARCH_TYPE_GLIB */
+
+    lc_mc_search->num_results =
+#ifdef HAVE_PCRE2
+        pcre2_match (regex, (unsigned char *) search_str->str, search_str->len, 0, 0,
+                     lc_mc_search->regex_match_info, NULL);
+#else
+        pcre_exec (regex, lc_mc_search->regex_match_info, search_str->str, search_str->len, 0, 0,
+                   lc_mc_search->iovector, MC_SEARCH__NUM_REPLACE_ARGS);
+#endif
+    if (lc_mc_search->num_results < 0)
+    {
+        return COND__NOT_FOUND;
+    }
+#endif /* SEARCH_TYPE_GLIB */
+    return COND__FOUND_OK;
+
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static mc_search__found_cond_t
+mc_search__regex_found_cond (mc_search_t * lc_mc_search, GString * search_str)
+{
+    gsize loop1;
+
+    for (loop1 = 0; loop1 < lc_mc_search->prepared.conditions->len; loop1++)
+    {
+        mc_search_cond_t *mc_search_cond;
+        mc_search__found_cond_t ret;
+
+        mc_search_cond =
+            (mc_search_cond_t *) g_ptr_array_index (lc_mc_search->prepared.conditions, loop1);
+
+        if (!mc_search_cond->regex_handle)
+            continue;
+
+        ret =
+            mc_search__regex_found_cond_one (lc_mc_search, mc_search_cond->regex_handle,
+                                             search_str);
+        if (ret != COND__NOT_FOUND)
+            return ret;
+    }
+    return COND__NOT_ALL_FOUND;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static int
+mc_search_regex__get_max_num_of_replace_tokens (const gchar * str, gsize len)
+{
+    int max_token = 0;
+    gsize loop;
+    for (loop = 0; loop < len - 1; loop++)
+    {
+        if (str[loop] == '\\' && g_ascii_isdigit (str[loop + 1]))
+        {
+            if (strutils_is_char_escaped (str, &str[loop]))
+                continue;
+            if (max_token < str[loop + 1] - '0')
+                max_token = str[loop + 1] - '0';
+            continue;
+        }
+        if (str[loop] == '$' && str[loop + 1] == '{')
+        {
+            gsize tmp_len;
+
+            if (strutils_is_char_escaped (str, &str[loop]))
+                continue;
+
+            for (tmp_len = 0;
+                 loop + tmp_len + 2 < len && (str[loop + 2 + tmp_len] & (char) 0xf0) == 0x30;
+                 tmp_len++);
+
+            if (str[loop + 2 + tmp_len] == '}')
+            {
+                int tmp_token;
+                char *tmp_str;
+
+                tmp_str = g_strndup (&str[loop + 2], tmp_len);
+                tmp_token = atoi (tmp_str);
+                if (max_token < tmp_token)
+                    max_token = tmp_token;
+                g_free (tmp_str);
+            }
+        }
+    }
+    return max_token;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static char *
+mc_search_regex__get_token_by_num (const mc_search_t * lc_mc_search, gsize lc_index)
+{
+    int fnd_start = 0, fnd_end = 0;
+
+#ifdef SEARCH_TYPE_GLIB
+    g_match_info_fetch_pos (lc_mc_search->regex_match_info, lc_index, &fnd_start, &fnd_end);
+#else /* SEARCH_TYPE_GLIB */
+    fnd_start = lc_mc_search->iovector[lc_index * 2 + 0];
+    fnd_end = lc_mc_search->iovector[lc_index * 2 + 1];
+#endif /* SEARCH_TYPE_GLIB */
+
+    if (fnd_end == fnd_start)
+        return g_strdup ("");
+
+    return g_strndup (lc_mc_search->regex_buffer->str + fnd_start, fnd_end - fnd_start);
+
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static gboolean
+mc_search_regex__replace_handle_esc_seq (const GString * replace_str, const gsize current_pos,
+                                         gsize * skip_len, int *ret)
+{
+    char *curr_str = &(replace_str->str[current_pos]);
+    char c = curr_str[1];
+
+    if (replace_str->len > current_pos + 2)
+    {
+        if (c == '{')
+        {
+            for (*skip_len = 2; /* \{ */
+                 current_pos + *skip_len < replace_str->len && curr_str[*skip_len] >= '0'
+                 && curr_str[*skip_len] <= '7'; (*skip_len)++)
+                ;
+
+            if (current_pos + *skip_len < replace_str->len && curr_str[*skip_len] == '}')
+            {
+                (*skip_len)++;
+                *ret = REPLACE_PREPARE_T_ESCAPE_SEQ;
+                return FALSE;
+            }
+            else
+            {
+                *ret = REPLACE_PREPARE_T_NOTHING_SPECIAL;
+                return TRUE;
+            }
+        }
+
+        if (c == 'x')
+        {
+            *skip_len = 2;      /* \x */
+            c = curr_str[2];
+            if (c == '{')
+            {
+                for (*skip_len = 3;     /* \x{ */
+                     current_pos + *skip_len < replace_str->len
+                     && g_ascii_isxdigit ((guchar) curr_str[*skip_len]); (*skip_len)++)
+                    ;
+
+                if (current_pos + *skip_len < replace_str->len && curr_str[*skip_len] == '}')
+                {
+                    (*skip_len)++;
+                    *ret = REPLACE_PREPARE_T_ESCAPE_SEQ;
+                    return FALSE;
+                }
+                else
+                {
+                    *ret = REPLACE_PREPARE_T_NOTHING_SPECIAL;
+                    return TRUE;
+                }
+            }
+            else if (!g_ascii_isxdigit ((guchar) c))
+            {
+                *skip_len = 2;  /* \x without number behind */
+                *ret = REPLACE_PREPARE_T_NOTHING_SPECIAL;
+                return FALSE;
+            }
+            else
+            {
+                c = curr_str[3];
+                if (!g_ascii_isxdigit ((guchar) c))
+                    *skip_len = 3;      /* \xH */
+                else
+                    *skip_len = 4;      /* \xHH */
+                *ret = REPLACE_PREPARE_T_ESCAPE_SEQ;
+                return FALSE;
+            }
+        }
+    }
+
+    if (strchr ("ntvbrfa", c) != NULL)
+    {
+        *skip_len = 2;
+        *ret = REPLACE_PREPARE_T_ESCAPE_SEQ;
+        return FALSE;
+    }
+    return TRUE;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static int
+mc_search_regex__process_replace_str (const GString * replace_str, const gsize current_pos,
+                                      gsize * skip_len, replace_transform_type_t * replace_flags)
+{
+    int ret = -1;
+    const char *curr_str = &(replace_str->str[current_pos]);
+
+    if (current_pos > replace_str->len)
+        return REPLACE_PREPARE_T_NOTHING_SPECIAL;
+
+    *skip_len = 0;
+
+    if (replace_str->len > current_pos + 2 && curr_str[0] == '$' && curr_str[1] == '{'
+        && (curr_str[2] & (char) 0xf0) == 0x30)
+    {
+        char *tmp_str;
+
+        if (strutils_is_char_escaped (replace_str->str, curr_str))
+        {
+            *skip_len = 1;
+            return REPLACE_PREPARE_T_NOTHING_SPECIAL;
+        }
+
+        for (*skip_len = 0;
+             current_pos + *skip_len + 2 < replace_str->len
+             && (curr_str[2 + *skip_len] & (char) 0xf0) == 0x30; (*skip_len)++)
+            ;
+
+        if (curr_str[2 + *skip_len] != '}')
+            return REPLACE_PREPARE_T_NOTHING_SPECIAL;
+
+        tmp_str = g_strndup (curr_str + 2, *skip_len);
+        if (tmp_str == NULL)
+            return REPLACE_PREPARE_T_NOTHING_SPECIAL;
+
+        ret = atoi (tmp_str);
+        g_free (tmp_str);
+
+        *skip_len += 3;         /* ${} */
+        return ret;             /* capture buffer index >= 0 */
+    }
+
+    if (curr_str[0] == '\\' && replace_str->len > current_pos + 1)
+    {
+        if (strutils_is_char_escaped (replace_str->str, curr_str))
+        {
+            *skip_len = 1;
+            return REPLACE_PREPARE_T_NOTHING_SPECIAL;
+        }
+
+        if (g_ascii_isdigit (curr_str[1]))
+        {
+            ret = g_ascii_digit_value (curr_str[1]);    /* capture buffer index >= 0 */
+            *skip_len = 2;      /* \\ and one digit */
+            return ret;
+        }
+
+        if (!mc_search_regex__replace_handle_esc_seq (replace_str, current_pos, skip_len, &ret))
+            return ret;
+
+        ret = REPLACE_PREPARE_T_REPLACE_FLAG;
+        *skip_len += 2;
+
+        switch (curr_str[1])
+        {
+        case 'U':
+            *replace_flags |= REPLACE_T_UPP_TRANSFORM;
+            *replace_flags &= ~REPLACE_T_LOW_TRANSFORM;
+            break;
+        case 'u':
+            *replace_flags |= REPLACE_T_UPP_TRANSFORM_CHAR;
+            break;
+        case 'L':
+            *replace_flags |= REPLACE_T_LOW_TRANSFORM;
+            *replace_flags &= ~REPLACE_T_UPP_TRANSFORM;
+            break;
+        case 'l':
+            *replace_flags |= REPLACE_T_LOW_TRANSFORM_CHAR;
+            break;
+        case 'E':
+            *replace_flags = REPLACE_T_NO_TRANSFORM;
+            break;
+        default:
+            ret = REPLACE_PREPARE_T_NOTHING_SPECIAL;
+            break;
+        }
+    }
+    return ret;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static void
+mc_search_regex__process_append_str (GString * dest_str, const char *from, gsize len,
+                                     replace_transform_type_t * replace_flags)
+{
+    gsize loop;
+    gsize char_len;
+
+    if (len == (gsize) (-1))
+        len = strlen (from);
+
+    if (*replace_flags == REPLACE_T_NO_TRANSFORM)
+    {
+        g_string_append_len (dest_str, from, len);
+        return;
+    }
+
+    for (loop = 0; loop < len; loop += char_len)
+    {
+        GString *tmp_string = NULL;
+        GString *s;
+
+        s = mc_search__get_one_symbol (NULL, from + loop, len - loop, NULL);
+        char_len = s->len;
+
+        if ((*replace_flags & REPLACE_T_UPP_TRANSFORM_CHAR) != 0)
+        {
+            *replace_flags &= ~REPLACE_T_UPP_TRANSFORM_CHAR;
+            tmp_string = mc_search__toupper_case_str (NULL, s);
+            g_string_append_len (dest_str, tmp_string->str, tmp_string->len);
+        }
+        else if ((*replace_flags & REPLACE_T_LOW_TRANSFORM_CHAR) != 0)
+        {
+            *replace_flags &= ~REPLACE_T_LOW_TRANSFORM_CHAR;
+            tmp_string = mc_search__tolower_case_str (NULL, s);
+            g_string_append_len (dest_str, tmp_string->str, tmp_string->len);
+        }
+        else if ((*replace_flags & REPLACE_T_UPP_TRANSFORM) != 0)
+        {
+            tmp_string = mc_search__toupper_case_str (NULL, s);
+            g_string_append_len (dest_str, tmp_string->str, tmp_string->len);
+        }
+        else if ((*replace_flags & REPLACE_T_LOW_TRANSFORM) != 0)
+        {
+            tmp_string = mc_search__tolower_case_str (NULL, s);
+            g_string_append_len (dest_str, tmp_string->str, tmp_string->len);
+        }
+
+        g_string_free (s, TRUE);
+        if (tmp_string != NULL)
+            g_string_free (tmp_string, TRUE);
+    }
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static void
+mc_search_regex__process_escape_sequence (GString * dest_str, const char *from, gsize len,
+                                          replace_transform_type_t * replace_flags,
+                                          gboolean is_utf8)
+{
+    gsize i = 0;
+    unsigned int c = 0;
+    char b;
+
+    if (len == (gsize) (-1))
+        len = strlen (from);
+    if (len == 0)
+        return;
+
+    if (from[i] == '{')
+        i++;
+    if (i >= len)
+        return;
+
+    if (from[i] == 'x')
+    {
+        i++;
+        if (i < len && from[i] == '{')
+            i++;
+        for (; i < len; i++)
+        {
+            if (from[i] >= '0' && from[i] <= '9')
+                c = c * 16 + from[i] - '0';
+            else if (from[i] >= 'a' && from[i] <= 'f')
+                c = c * 16 + 10 + from[i] - 'a';
+            else if (from[i] >= 'A' && from[i] <= 'F')
+                c = c * 16 + 10 + from[i] - 'A';
+            else
+                break;
+        }
+    }
+    else if (from[i] >= '0' && from[i] <= '7')
+        for (; i < len && from[i] >= '0' && from[i] <= '7'; i++)
+            c = c * 8 + from[i] - '0';
+    else
+    {
+        switch (from[i])
+        {
+        case 'n':
+            c = '\n';
+            break;
+        case 't':
+            c = '\t';
+            break;
+        case 'v':
+            c = '\v';
+            break;
+        case 'b':
+            c = '\b';
+            break;
+        case 'r':
+            c = '\r';
+            break;
+        case 'f':
+            c = '\f';
+            break;
+        case 'a':
+            c = '\a';
+            break;
+        default:
+            mc_search_regex__process_append_str (dest_str, from, len, replace_flags);
+            return;
+        }
+    }
+
+    if (c < 0x80 || !is_utf8)
+        g_string_append_c (dest_str, (char) c);
+    else if (c < 0x800)
+    {
+        b = 0xC0 | (c >> 6);
+        g_string_append_c (dest_str, b);
+        b = 0x80 | (c & 0x3F);
+        g_string_append_c (dest_str, b);
+    }
+    else if (c < 0x10000)
+    {
+        b = 0xE0 | (c >> 12);
+        g_string_append_c (dest_str, b);
+        b = 0x80 | ((c >> 6) & 0x3F);
+        g_string_append_c (dest_str, b);
+        b = 0x80 | (c & 0x3F);
+        g_string_append_c (dest_str, b);
+    }
+    else if (c < 0x10FFFF)
+    {
+        b = 0xF0 | (c >> 16);
+        g_string_append_c (dest_str, b);
+        b = 0x80 | ((c >> 12) & 0x3F);
+        g_string_append_c (dest_str, b);
+        b = 0x80 | ((c >> 6) & 0x3F);
+        g_string_append_c (dest_str, b);
+        b = 0x80 | (c & 0x3F);
+        g_string_append_c (dest_str, b);
+    }
+}
+
+/* --------------------------------------------------------------------------------------------- */
+/*** public functions ****************************************************************************/
+/* --------------------------------------------------------------------------------------------- */
+
+void
+mc_search__cond_struct_new_init_regex (const char *charset, mc_search_t * lc_mc_search,
+                                       mc_search_cond_t * mc_search_cond)
+{
+    if (lc_mc_search->whole_words && !lc_mc_search->is_entire_line)
+    {
+        /* NOTE: \b as word boundary doesn't allow search
+         * whole words with non-ASCII symbols.
+         * Update: Is it still true nowadays? Probably not. #2396, #3524 */
+        g_string_prepend (mc_search_cond->str, "(?<![\\p{L}\\p{N}_])");
+        g_string_append (mc_search_cond->str, "(?![\\p{L}\\p{N}_])");
+    }
+
+    {
+#ifdef SEARCH_TYPE_GLIB
+        GError *mcerror = NULL;
+        GRegexCompileFlags g_regex_options = G_REGEX_OPTIMIZE | G_REGEX_DOTALL;
+
+        if (str_isutf8 (charset) && mc_global.utf8_display)
+        {
+            if (!lc_mc_search->is_case_sensitive)
+                g_regex_options |= G_REGEX_CASELESS;
+        }
+        else
+        {
+            g_regex_options |= G_REGEX_RAW;
+
+            if (!lc_mc_search->is_case_sensitive)
+            {
+                GString *tmp;
+
+                tmp = mc_search_cond->str;
+                mc_search_cond->str = mc_search__cond_struct_new_regex_ci_str (charset, tmp);
+                g_string_free (tmp, TRUE);
+            }
+        }
+
+        mc_search_cond->regex_handle =
+            g_regex_new (mc_search_cond->str->str, g_regex_options, 0, &mcerror);
+
+        if (mcerror != NULL)
+        {
+            lc_mc_search->error = MC_SEARCH_E_REGEX_COMPILE;
+            g_free (lc_mc_search->error_str);
+            lc_mc_search->error_str =
+                str_conv_gerror_message (mcerror, _("Regular expression error"));
+            g_error_free (mcerror);
+            return;
+        }
+#else /* SEARCH_TYPE_GLIB */
+
+#ifdef HAVE_PCRE2
+        int errcode;
+        char error[BUF_SMALL];
+        size_t erroffset;
+        int pcre_options = PCRE2_MULTILINE;
+#else
+        const char *error;
+        int erroffset;
+        int pcre_options = PCRE_EXTRA | PCRE_MULTILINE;
+#endif
+
+        if (str_isutf8 (charset) && mc_global.utf8_display)
+        {
+#ifdef HAVE_PCRE2
+            pcre_options |= PCRE2_UTF;
+            if (!lc_mc_search->is_case_sensitive)
+                pcre_options |= PCRE2_CASELESS;
+#else
+            pcre_options |= PCRE_UTF8;
+            if (!lc_mc_search->is_case_sensitive)
+                pcre_options |= PCRE_CASELESS;
+#endif
+        }
+        else if (!lc_mc_search->is_case_sensitive)
+        {
+            GString *tmp;
+
+            tmp = mc_search_cond->str;
+            mc_search_cond->str = mc_search__cond_struct_new_regex_ci_str (charset, tmp);
+            g_string_free (tmp, TRUE);
+        }
+
+        mc_search_cond->regex_handle =
+#ifdef HAVE_PCRE2
+            pcre2_compile ((unsigned char *) mc_search_cond->str->str, PCRE2_ZERO_TERMINATED,
+                           pcre_options, &errcode, &erroffset, NULL);
+#else
+            pcre_compile (mc_search_cond->str->str, pcre_options, &error, &erroffset, NULL);
+#endif
+        if (mc_search_cond->regex_handle == NULL)
+        {
+#ifdef HAVE_PCRE2
+            pcre2_get_error_message (errcode, (unsigned char *) error, sizeof (error));
+#endif
+            mc_search_set_error (lc_mc_search, MC_SEARCH_E_REGEX_COMPILE, "%s", error);
+            return;
+        }
+#ifdef HAVE_PCRE2
+        if (pcre2_jit_compile (mc_search_cond->regex_handle, PCRE2_JIT_COMPLETE) && *error != '\0')
+#else
+        lc_mc_search->regex_match_info = pcre_study (mc_search_cond->regex_handle, 0, &error);
+        if (lc_mc_search->regex_match_info == NULL && error != NULL)
+#endif
+        {
+            mc_search_set_error (lc_mc_search, MC_SEARCH_E_REGEX_COMPILE, "%s", error);
+            MC_PTR_FREE (mc_search_cond->regex_handle);
+            return;
+        }
+#endif /* SEARCH_TYPE_GLIB */
+    }
+
+    lc_mc_search->is_utf8 = str_isutf8 (charset);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+gboolean
+mc_search__run_regex (mc_search_t * lc_mc_search, const void *user_data,
+                      gsize start_search, gsize end_search, gsize * found_len)
+{
+    mc_search_cbret_t ret = MC_SEARCH_CB_NOTFOUND;
+    gsize current_pos, virtual_pos;
+    gint start_pos;
+    gint end_pos;
+
+    if (lc_mc_search->regex_buffer != NULL)
+        g_string_set_size (lc_mc_search->regex_buffer, 0);
+    else
+        lc_mc_search->regex_buffer = g_string_sized_new (64);
+
+    virtual_pos = current_pos = start_search;
+    while (virtual_pos <= end_search)
+    {
+        g_string_set_size (lc_mc_search->regex_buffer, 0);
+        lc_mc_search->start_buffer = current_pos;
+
+        if (lc_mc_search->search_fn != NULL)
+        {
+            while (TRUE)
+            {
+                int current_chr = '\n'; /* stop search symbol */
+
+                ret = lc_mc_search->search_fn (user_data, current_pos, &current_chr);
+
+                if (ret == MC_SEARCH_CB_ABORT)
+                    break;
+
+                if (ret == MC_SEARCH_CB_INVALID)
+                    continue;
+
+                current_pos++;
+
+                if (ret == MC_SEARCH_CB_SKIP)
+                    continue;
+
+                virtual_pos++;
+
+                g_string_append_c (lc_mc_search->regex_buffer, (char) current_chr);
+
+                if ((char) current_chr == '\n' || virtual_pos > end_search)
+                    break;
+            }
+        }
+        else
+        {
+            /* optimization for standard case (for search from file manager)
+             *  where there is no MC_SEARCH_CB_INVALID or MC_SEARCH_CB_SKIP
+             *  return codes, so we can copy line at regex buffer all at once
+             */
+            while (TRUE)
+            {
+                const char current_chr = ((const char *) user_data)[current_pos];
+
+                if (current_chr == '\0')
+                    break;
+
+                current_pos++;
+
+                if (current_chr == '\n' || current_pos > end_search)
+                    break;
+            }
+
+            /* use virtual_pos as index of start of current chunk */
+            g_string_append_len (lc_mc_search->regex_buffer, (const char *) user_data + virtual_pos,
+                                 current_pos - virtual_pos);
+            virtual_pos = current_pos;
+        }
+
+        switch (mc_search__regex_found_cond (lc_mc_search, lc_mc_search->regex_buffer))
+        {
+        case COND__FOUND_OK:
+#ifdef SEARCH_TYPE_GLIB
+            g_match_info_fetch_pos (lc_mc_search->regex_match_info, 0, &start_pos, &end_pos);
+#else /* SEARCH_TYPE_GLIB */
+            start_pos = lc_mc_search->iovector[0];
+            end_pos = lc_mc_search->iovector[1];
+#endif /* SEARCH_TYPE_GLIB */
+            if (found_len != NULL)
+                *found_len = end_pos - start_pos;
+            lc_mc_search->normal_offset = lc_mc_search->start_buffer + start_pos;
+            return TRUE;
+        case COND__NOT_ALL_FOUND:
+            break;
+        default:
+            g_string_free (lc_mc_search->regex_buffer, TRUE);
+            lc_mc_search->regex_buffer = NULL;
+            return FALSE;
+        }
+
+        if ((lc_mc_search->update_fn != NULL) &&
+            ((lc_mc_search->update_fn) (user_data, current_pos) == MC_SEARCH_CB_ABORT))
+            ret = MC_SEARCH_CB_ABORT;
+
+        if (ret == MC_SEARCH_CB_ABORT || ret == MC_SEARCH_CB_NOTFOUND)
+            break;
+    }
+
+    g_string_free (lc_mc_search->regex_buffer, TRUE);
+    lc_mc_search->regex_buffer = NULL;
+
+    MC_PTR_FREE (lc_mc_search->error_str);
+    lc_mc_search->error = ret == MC_SEARCH_CB_ABORT ? MC_SEARCH_E_ABORT : MC_SEARCH_E_NOTFOUND;
+
+    return FALSE;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+GString *
+mc_search_regex_prepare_replace_str (mc_search_t * lc_mc_search, GString * replace_str)
+{
+    GString *ret;
+
+    int num_replace_tokens;
+    gsize loop;
+    gsize prev = 0;
+    replace_transform_type_t replace_flags = REPLACE_T_NO_TRANSFORM;
+
+    num_replace_tokens =
+        mc_search_regex__get_max_num_of_replace_tokens (replace_str->str, replace_str->len);
+
+    if (lc_mc_search->num_results < 0)
+        return mc_g_string_dup (replace_str);
+
+    if (num_replace_tokens > lc_mc_search->num_results - 1
+        || num_replace_tokens > MC_SEARCH__NUM_REPLACE_ARGS)
+    {
+        mc_search_set_error (lc_mc_search, MC_SEARCH_E_REGEX_REPLACE, "%s",
+                             _(STR_E_RPL_NOT_EQ_TO_FOUND));
+        return NULL;
+    }
+
+    ret = g_string_sized_new (64);
+
+    for (loop = 0; loop < replace_str->len - 1; loop++)
+    {
+        int lc_index;
+        gchar *tmp_str;
+        gsize len = 0;
+
+        lc_index = mc_search_regex__process_replace_str (replace_str, loop, &len, &replace_flags);
+
+        if (lc_index == REPLACE_PREPARE_T_NOTHING_SPECIAL)
+        {
+            if (len != 0)
+            {
+                mc_search_regex__process_append_str (ret, replace_str->str + prev, loop - prev,
+                                                     &replace_flags);
+                mc_search_regex__process_append_str (ret, replace_str->str + loop + 1, len - 1,
+                                                     &replace_flags);
+                prev = loop + len;
+                loop = prev - 1;        /* prepare to loop++ */
+            }
+
+            continue;
+        }
+
+        if (lc_index == REPLACE_PREPARE_T_REPLACE_FLAG)
+        {
+            if (loop != 0)
+                mc_search_regex__process_append_str (ret, replace_str->str + prev, loop - prev,
+                                                     &replace_flags);
+            prev = loop + len;
+            loop = prev - 1;    /* prepare to loop++ */
+            continue;
+        }
+
+        /* escape sequence */
+        if (lc_index == REPLACE_PREPARE_T_ESCAPE_SEQ)
+        {
+            mc_search_regex__process_append_str (ret, replace_str->str + prev, loop - prev,
+                                                 &replace_flags);
+            /* call process_escape_sequence without starting '\\' */
+            mc_search_regex__process_escape_sequence (ret, replace_str->str + loop + 1, len - 1,
+                                                      &replace_flags, lc_mc_search->is_utf8);
+            prev = loop + len;
+            loop = prev - 1;    /* prepare to loop++ */
+            continue;
+        }
+
+        /* invalid capture buffer number */
+        if (lc_index > lc_mc_search->num_results)
+        {
+            g_string_free (ret, TRUE);
+            mc_search_set_error (lc_mc_search, MC_SEARCH_E_REGEX_REPLACE,
+                                 _(STR_E_RPL_INVALID_TOKEN), lc_index);
+            return NULL;
+        }
+
+        tmp_str = mc_search_regex__get_token_by_num (lc_mc_search, lc_index);
+
+        if (loop != 0)
+            mc_search_regex__process_append_str (ret, replace_str->str + prev, loop - prev,
+                                                 &replace_flags);
+
+        mc_search_regex__process_append_str (ret, tmp_str, -1, &replace_flags);
+        g_free (tmp_str);
+
+        prev = loop + len;
+        loop = prev - 1;        /* prepare to loop++ */
+    }
+
+    mc_search_regex__process_append_str (ret, replace_str->str + prev, replace_str->len - prev,
+                                         &replace_flags);
+
+    return ret;
+}