1 files changed, 760 insertions, 0 deletions

diff --git a/src/main/packages.c b/src/main/packages.c
new file mode 100644
index 0000000..aba9ba7
--- /dev/null
+++ b/src/main/packages.c
@@ -0,0 +1,760 @@
+/*
+ * dpkg - main program for package management
+ * packages.c - common to actions that process packages
+ *
+ * Copyright © 1994,1995 Ian Jackson <ijackson@chiark.greenend.org.uk>
+ * Copyright © 2006-2014 Guillem Jover <guillem@debian.org>
+ * Copyright © 2011 Linaro Limited
+ * Copyright © 2011 Raphaël Hertzog <hertzog@debian.org>
+ *
+ * This 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This 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 <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <compat.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <string.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <dpkg/i18n.h>
+#include <dpkg/dpkg.h>
+#include <dpkg/dpkg-db.h>
+#include <dpkg/pkg-list.h>
+#include <dpkg/pkg-queue.h>
+#include <dpkg/string.h>
+#include <dpkg/options.h>
+#include <dpkg/db-ctrl.h>
+#include <dpkg/db-fsys.h>
+
+#include "main.h"
+
+static struct pkginfo *progress_bytrigproc;
+static struct pkg_queue queue = PKG_QUEUE_INIT;
+
+enum dependtry dependtry = DEPEND_TRY_NORMAL;
+int sincenothing = 0;
+
+void
+enqueue_package(struct pkginfo *pkg)
+{
+  ensure_package_clientdata(pkg);
+  if (pkg->clientdata->enqueued)
+    return;
+  pkg->clientdata->enqueued = true;
+  pkg_queue_push(&queue, pkg);
+}
+
+void
+enqueue_package_mark_seen(struct pkginfo *pkg)
+{
+  enqueue_package(pkg);
+  pkg->clientdata->cmdline_seen++;
+}
+
+static void
+enqueue_pending(void)
+{
+  struct pkg_hash_iter *iter;
+  struct pkginfo *pkg;
+
+  iter = pkg_hash_iter_new();
+  while ((pkg = pkg_hash_iter_next_pkg(iter)) != NULL) {
+    switch (cipaction->arg_int) {
+    case act_configure:
+      if (!(pkg->status == PKG_STAT_UNPACKED ||
+            pkg->status == PKG_STAT_HALFCONFIGURED ||
+            pkg->trigpend_head))
+        continue;
+      if (pkg->want != PKG_WANT_INSTALL &&
+          pkg->want != PKG_WANT_HOLD)
+        continue;
+      break;
+    case act_triggers:
+      if (!pkg->trigpend_head)
+        continue;
+      if (pkg->want != PKG_WANT_INSTALL &&
+          pkg->want != PKG_WANT_HOLD)
+        continue;
+      break;
+    case act_remove:
+    case act_purge:
+      if (pkg->want != PKG_WANT_PURGE) {
+        if (pkg->want != PKG_WANT_DEINSTALL)
+          continue;
+        if (pkg->status == PKG_STAT_CONFIGFILES)
+          continue;
+      }
+      if (pkg->status == PKG_STAT_NOTINSTALLED)
+        continue;
+      break;
+    default:
+      internerr("unknown action '%d'", cipaction->arg_int);
+    }
+    enqueue_package(pkg);
+  }
+  pkg_hash_iter_free(iter);
+}
+
+static void
+enqueue_specified(const char *const *argv)
+{
+  const char *thisarg;
+
+  while ((thisarg = *argv++) != NULL) {
+    struct pkginfo *pkg;
+
+    pkg = dpkg_options_parse_pkgname(cipaction, thisarg);
+    if (pkg->status == PKG_STAT_NOTINSTALLED &&
+        str_match_end(pkg->set->name, DEBEXT)) {
+      badusage(_("you must specify packages by their own names, "
+                 "not by quoting the names of the files they come in"));
+    }
+    enqueue_package_mark_seen(pkg);
+  }
+
+  if (cipaction->arg_int == act_configure)
+    trigproc_populate_deferred();
+}
+
+int
+packages(const char *const *argv)
+{
+  trigproc_install_hooks();
+
+  modstatdb_open(f_noact ?                  msdbrw_readonly :
+                 in_force(FORCE_NON_ROOT) ? msdbrw_write :
+                                            msdbrw_needsuperuser);
+  checkpath();
+  pkg_infodb_upgrade();
+
+  log_message("startup packages %s", cipaction->olong);
+
+  if (f_pending) {
+    if (*argv)
+      badusage(_("--%s --pending does not take any non-option arguments"),cipaction->olong);
+
+    enqueue_pending();
+  } else {
+    if (!*argv)
+      badusage(_("--%s (without --pending) needs at least one package name argument"),
+               cipaction->olong);
+
+    enqueue_specified(argv);
+  }
+
+  ensure_diversions();
+
+  process_queue();
+  trigproc_run_deferred();
+
+  modstatdb_shutdown();
+
+  return 0;
+}
+
+void process_queue(void) {
+  struct pkg_list *rundown;
+  volatile enum action action_todo;
+  jmp_buf ejbuf;
+  enum pkg_istobe istobe = PKG_ISTOBE_NORMAL;
+
+  if (abort_processing)
+    return;
+
+  clear_istobes();
+
+  switch (cipaction->arg_int) {
+  case act_triggers:
+  case act_configure:
+  case act_install:
+    istobe = PKG_ISTOBE_INSTALLNEW;
+    break;
+  case act_remove:
+  case act_purge:
+    istobe = PKG_ISTOBE_REMOVE;
+    break;
+  default:
+    internerr("unknown action '%d'", cipaction->arg_int);
+  }
+  for (rundown = queue.head; rundown; rundown = rundown->next) {
+    ensure_package_clientdata(rundown->pkg);
+
+    /* We have processed this package more than once. There are no duplicates
+     * as we make sure of that when enqueuing them. */
+    if (rundown->pkg->clientdata->cmdline_seen > 1) {
+      switch (cipaction->arg_int) {
+      case act_triggers:
+      case act_configure: case act_remove: case act_purge:
+        printf(_("Package %s listed more than once, only processing once.\n"),
+               pkg_name(rundown->pkg, pnaw_nonambig));
+        break;
+      case act_install:
+        printf(_("More than one copy of package %s has been unpacked\n"
+               " in this run !  Only configuring it once.\n"),
+               pkg_name(rundown->pkg, pnaw_nonambig));
+        break;
+      default:
+        internerr("unknown action '%d'", cipaction->arg_int);
+      }
+    }
+    rundown->pkg->clientdata->istobe = istobe;
+  }
+
+  while (!pkg_queue_is_empty(&queue)) {
+    struct pkginfo *volatile pkg;
+
+    pkg = pkg_queue_pop(&queue);
+    if (!pkg)
+      continue; /* Duplicate, which we removed earlier. */
+
+    ensure_package_clientdata(pkg);
+    pkg->clientdata->enqueued = false;
+
+    action_todo = cipaction->arg_int;
+
+    if (sincenothing++ > queue.length * 3 + 2) {
+      /* Make sure that even if we have exceeded the queue since not having
+       * made any progress, we are not getting stuck trying to progress by
+       * trigger processing, w/o jumping into the next dependtry. */
+      dependtry++;
+      sincenothing = 0;
+      if (dependtry >= DEPEND_TRY_LAST)
+        internerr("exceeded dependtry %d (sincenothing=%d; queue.length=%d)",
+                  dependtry, sincenothing, queue.length);
+    } else if (sincenothing > queue.length * 2 + 2) {
+      if (dependtry >= DEPEND_TRY_TRIGGERS &&
+          progress_bytrigproc && progress_bytrigproc->trigpend_head) {
+        enqueue_package(pkg);
+        pkg = progress_bytrigproc;
+        progress_bytrigproc = NULL;
+        action_todo = act_configure;
+      } else {
+        dependtry++;
+        sincenothing = 0;
+        if (dependtry >= DEPEND_TRY_LAST)
+          internerr("exceeded dependtry %d (sincenothing=%d, queue.length=%d)",
+                    dependtry, sincenothing, queue.length);
+      }
+    }
+
+    debug(dbg_general, "process queue pkg %s queue.len %d progress %d, try %d",
+          pkg_name(pkg, pnaw_always), queue.length, sincenothing, dependtry);
+
+    if (pkg->status > PKG_STAT_INSTALLED)
+      internerr("package %s status %d is out-of-bounds",
+                pkg_name(pkg, pnaw_always), pkg->status);
+
+    if (setjmp(ejbuf)) {
+      /* Give up on it from the point of view of other packages, i.e. reset
+       * istobe. */
+      pkg->clientdata->istobe = PKG_ISTOBE_NORMAL;
+
+      pop_error_context(ehflag_bombout);
+      if (abort_processing)
+        return;
+      continue;
+    }
+    push_error_context_jump(&ejbuf, print_error_perpackage,
+                            pkg_name(pkg, pnaw_nonambig));
+
+    switch (action_todo) {
+    case act_triggers:
+      if (!pkg->trigpend_head)
+        ohshit(_("package %.250s is not ready for trigger processing\n"
+                 " (current status '%.250s' with no pending triggers)"),
+               pkg_name(pkg, pnaw_nonambig), pkg_status_name(pkg));
+      /* Fall through. */
+    case act_install:
+      /* Don't try to configure pkgs that we've just disappeared. */
+      if (pkg->status == PKG_STAT_NOTINSTALLED)
+        break;
+      /* Fall through. */
+    case act_configure:
+      /* Do whatever is most needed. */
+      if (pkg->trigpend_head)
+        trigproc(pkg, TRIGPROC_TRY_QUEUED);
+      else
+        deferred_configure(pkg);
+      break;
+    case act_remove: case act_purge:
+      deferred_remove(pkg);
+      break;
+    default:
+      internerr("unknown action '%d'", cipaction->arg_int);
+    }
+    m_output(stdout, _("<standard output>"));
+    m_output(stderr, _("<standard error>"));
+
+    pop_error_context(ehflag_normaltidy);
+  }
+
+  if (queue.length)
+    internerr("finished package processing with non-empty queue length %d",
+              queue.length);
+}
+
+/*** Dependency processing - common to --configure and --remove. ***/
+
+/*
+ * The algorithm for deciding what to configure or remove first is as
+ * follows:
+ *
+ * Loop through all packages doing a ‘try 1’ until we've been round and
+ * nothing has been done, then do ‘try 2’ and ‘try 3’ likewise.
+ *
+ * When configuring, in each try we check to see whether all
+ * dependencies of this package are done. If so we do it. If some of
+ * the dependencies aren't done yet but will be later we defer the
+ * package, otherwise it is an error.
+ *
+ * When removing, in each try we check to see whether there are any
+ * packages that would have dependencies missing if we removed this
+ * one. If not we remove it now. If some of these packages are
+ * themselves scheduled for removal we defer the package until they
+ * have been done.
+ *
+ * The criteria for satisfying a dependency vary with the various
+ * tries. In try 1 we treat the dependencies as absolute. In try 2 we
+ * check break any cycles in the dependency graph involving the package
+ * we are trying to process before trying to process the package
+ * normally. In try 3 (which should only be reached if
+ * --force-depends-version is set) we ignore version number clauses in
+ * Depends lines. In try 4 (only reached if --force-depends is set) we
+ * say "ok" regardless.
+ *
+ * If we are configuring and one of the packages we depend on is
+ * awaiting configuration but wasn't specified in the argument list we
+ * will add it to the argument list if --configure-any is specified.
+ * In this case we note this as having "done something" so that we
+ * don't needlessly escalate to higher levels of dependency checking
+ * and breaking.
+ */
+
+enum found_status {
+  FOUND_NONE = 0,
+  FOUND_DEFER = 1,
+  FOUND_FORCED = 2,
+  FOUND_OK = 3,
+};
+
+static enum found_status
+found_forced_on(enum dependtry dependtry_forced)
+{
+  if (dependtry >= dependtry_forced)
+    return FOUND_FORCED;
+  else
+    return FOUND_DEFER;
+}
+
+/*
+ * Return values:
+ *   0: cannot be satisfied.
+ *   1: defer: may be satisfied later, when other packages are better or
+ *      at higher dependtry due to --force
+ *      will set *fixbytrig to package whose trigger processing would help
+ *      if applicable (and leave it alone otherwise).
+ *   2: not satisfied but forcing
+ *      (*interestingwarnings >= 0 on exit? caller is to print oemsgs).
+ *   3: satisfied now.
+ */
+static enum found_status
+deppossi_ok_found(struct pkginfo *possdependee, struct pkginfo *requiredby,
+                  struct pkginfo *removing, struct deppossi *provider,
+                  struct pkginfo **fixbytrig,
+                  bool *matched, struct deppossi *checkversion,
+                  int *interestingwarnings, struct varbuf *oemsgs)
+{
+  enum found_status thisf;
+
+  if (ignore_depends(possdependee)) {
+    debug(dbg_depcondetail,"      ignoring depended package so ok and found");
+    return FOUND_OK;
+  }
+  thisf = FOUND_NONE;
+  if (possdependee == removing) {
+    if (provider) {
+      varbuf_printf(oemsgs,
+                    _("  Package %s which provides %s is to be removed.\n"),
+                    pkg_name(possdependee, pnaw_nonambig),
+                    provider->ed->name);
+    } else {
+      varbuf_printf(oemsgs, _("  Package %s is to be removed.\n"),
+                    pkg_name(possdependee, pnaw_nonambig));
+    }
+
+    *matched = true;
+    debug(dbg_depcondetail,"      removing possdependee, returning %d",thisf);
+    return thisf;
+  }
+  switch (possdependee->status) {
+  case PKG_STAT_UNPACKED:
+  case PKG_STAT_HALFCONFIGURED:
+  case PKG_STAT_TRIGGERSAWAITED:
+  case PKG_STAT_TRIGGERSPENDING:
+  case PKG_STAT_INSTALLED:
+    if (checkversion) {
+      if (provider) {
+        debug(dbg_depcondetail, "      checking package %s provided by pkg %s",
+              checkversion->ed->name, pkg_name(possdependee, pnaw_always));
+        if (!pkg_virtual_deppossi_satisfied(checkversion, provider)) {
+          varbuf_printf(oemsgs,
+                        _("  Version of %s on system, provided by %s, is %s.\n"),
+                        checkversion->ed->name,
+                        pkg_name(possdependee, pnaw_always),
+                        versiondescribe(&provider->version, vdew_nonambig));
+          if (in_force(FORCE_DEPENDS_VERSION))
+            thisf = found_forced_on(DEPEND_TRY_FORCE_DEPENDS_VERSION);
+          debug(dbg_depcondetail, "      bad version");
+          goto unsuitable;
+        }
+      } else {
+        debug(dbg_depcondetail, "      checking non-provided pkg %s",
+              pkg_name(possdependee, pnaw_always));
+        if (!versionsatisfied(&possdependee->installed, checkversion)) {
+          varbuf_printf(oemsgs, _("  Version of %s on system is %s.\n"),
+                        pkg_name(possdependee, pnaw_nonambig),
+                        versiondescribe(&possdependee->installed.version,
+                                        vdew_nonambig));
+          if (in_force(FORCE_DEPENDS_VERSION))
+            thisf = found_forced_on(DEPEND_TRY_FORCE_DEPENDS_VERSION);
+          debug(dbg_depcondetail, "      bad version");
+          goto unsuitable;
+        }
+      }
+    }
+    if (possdependee->status == PKG_STAT_INSTALLED ||
+        possdependee->status == PKG_STAT_TRIGGERSPENDING) {
+      debug(dbg_depcondetail,"      is installed, ok and found");
+      return FOUND_OK;
+    }
+    if (possdependee->status == PKG_STAT_TRIGGERSAWAITED) {
+      if (possdependee->trigaw.head == NULL)
+        internerr("package %s in state %s, has no awaited triggers",
+                  pkg_name(possdependee, pnaw_always),
+                  pkg_status_name(possdependee));
+
+      if (removing ||
+          !(f_triggers ||
+            (possdependee->clientdata &&
+             possdependee->clientdata->istobe == PKG_ISTOBE_INSTALLNEW))) {
+        if (provider) {
+          varbuf_printf(oemsgs,
+                        _("  Package %s which provides %s awaits trigger processing.\n"),
+                        pkg_name(possdependee, pnaw_nonambig),
+                        provider->ed->name);
+        } else {
+          varbuf_printf(oemsgs,
+                        _("  Package %s awaits trigger processing.\n"),
+                        pkg_name(possdependee, pnaw_nonambig));
+        }
+        debug(dbg_depcondetail, "      triggers-awaited, no fixbytrig");
+        goto unsuitable;
+      }
+      /* We don't check the status of trigaw.head->pend here, just in case
+       * we get into the pathological situation where Triggers-Awaited but
+       * the named package doesn't actually have any pending triggers. In
+       * that case we queue the non-pending package for trigger processing
+       * anyway, and that trigger processing will be a noop except for
+       * sorting out all of the packages which name it in Triggers-Awaited.
+       *
+       * (This situation can only arise if modstatdb_note success in
+       * clearing the triggers-pending status of the pending package
+       * but then fails to go on to update the awaiters.) */
+      *fixbytrig = possdependee->trigaw.head->pend;
+      debug(dbg_depcondetail,
+            "      triggers-awaited, fixbytrig '%s', defer",
+            pkg_name(*fixbytrig, pnaw_always));
+      return FOUND_DEFER;
+    }
+    if (possdependee->clientdata &&
+        possdependee->clientdata->istobe == PKG_ISTOBE_INSTALLNEW) {
+      debug(dbg_depcondetail,"      unpacked/halfconfigured, defer");
+      return FOUND_DEFER;
+    } else if (!removing && in_force(FORCE_CONFIGURE_ANY) &&
+               !skip_due_to_hold(possdependee) &&
+               !(possdependee->status == PKG_STAT_HALFCONFIGURED)) {
+      notice(_("also configuring '%s' (required by '%s')"),
+             pkg_name(possdependee, pnaw_nonambig),
+             pkg_name(requiredby, pnaw_nonambig));
+      enqueue_package(possdependee);
+      sincenothing = 0;
+      return FOUND_DEFER;
+    } else {
+      if (provider) {
+        varbuf_printf(oemsgs,
+                      _("  Package %s which provides %s is not configured yet.\n"),
+                      pkg_name(possdependee, pnaw_nonambig),
+                      provider->ed->name);
+      } else {
+        varbuf_printf(oemsgs, _("  Package %s is not configured yet.\n"),
+                      pkg_name(possdependee, pnaw_nonambig));
+      }
+
+      debug(dbg_depcondetail, "      not configured/able");
+      goto unsuitable;
+    }
+
+  default:
+    if (provider) {
+      varbuf_printf(oemsgs,
+                    _("  Package %s which provides %s is not installed.\n"),
+                    pkg_name(possdependee, pnaw_nonambig),
+                    provider->ed->name);
+    } else {
+      varbuf_printf(oemsgs, _("  Package %s is not installed.\n"),
+                    pkg_name(possdependee, pnaw_nonambig));
+    }
+
+    debug(dbg_depcondetail, "      not installed");
+    goto unsuitable;
+  }
+
+unsuitable:
+  debug(dbg_depcondetail, "        returning %d", thisf);
+  (*interestingwarnings)++;
+
+  return thisf;
+}
+
+static void
+breaks_check_one(struct varbuf *aemsgs, enum dep_check *ok,
+                 struct deppossi *breaks, struct pkginfo *broken,
+                 struct pkginfo *breaker, struct deppossi *virtbroken)
+{
+  struct varbuf depmsg = VARBUF_INIT;
+
+  debug(dbg_depcondetail, "      checking breaker %s virtbroken %s",
+        pkg_name(breaker, pnaw_always),
+        virtbroken ? virtbroken->ed->name : "<none>");
+
+  if (breaker->status == PKG_STAT_NOTINSTALLED ||
+      breaker->status == PKG_STAT_CONFIGFILES)
+    return;
+  if (broken == breaker) return;
+  if (!versionsatisfied(&broken->installed, breaks)) return;
+  /* The test below can only trigger if dep_breaks start having
+   * arch qualifiers different from “any”. */
+  if (!archsatisfied(&broken->installed, breaks))
+    return;
+  if (ignore_depends(breaker)) return;
+  if (virtbroken && ignore_depends(&virtbroken->ed->pkg))
+    return;
+  if (virtbroken && !pkg_virtual_deppossi_satisfied(breaks, virtbroken))
+    return;
+
+  varbufdependency(&depmsg, breaks->up);
+  varbuf_end_str(&depmsg);
+  varbuf_printf(aemsgs, _(" %s (%s) breaks %s and is %s.\n"),
+                pkg_name(breaker, pnaw_nonambig),
+                versiondescribe(&breaker->installed.version, vdew_nonambig),
+                depmsg.buf, gettext(statusstrings[breaker->status]));
+  varbuf_destroy(&depmsg);
+
+  if (virtbroken) {
+    varbuf_printf(aemsgs, _("  %s (%s) provides %s.\n"),
+                  pkg_name(broken, pnaw_nonambig),
+                  versiondescribe(&broken->installed.version, vdew_nonambig),
+                  virtbroken->ed->name);
+  } else if (breaks->verrel != DPKG_RELATION_NONE) {
+    varbuf_printf(aemsgs, _("  Version of %s to be configured is %s.\n"),
+                  pkg_name(broken, pnaw_nonambig),
+                  versiondescribe(&broken->installed.version, vdew_nonambig));
+    if (in_force(FORCE_DEPENDS_VERSION))
+      return;
+  }
+  if (force_breaks(breaks)) return;
+  *ok = DEP_CHECK_HALT;
+}
+
+static void
+breaks_check_target(struct varbuf *aemsgs, enum dep_check *ok,
+                    struct pkginfo *broken, struct pkgset *target,
+                    struct deppossi *virtbroken)
+{
+  struct deppossi *possi;
+
+  for (possi = target->depended.installed; possi; possi = possi->rev_next) {
+    if (possi->up->type != dep_breaks) continue;
+    breaks_check_one(aemsgs, ok, possi, broken, possi->up->up, virtbroken);
+  }
+}
+
+enum dep_check
+breakses_ok(struct pkginfo *pkg, struct varbuf *aemsgs)
+{
+  struct dependency *dep;
+  struct deppossi *virtbroken;
+  enum dep_check ok = DEP_CHECK_OK;
+
+  debug(dbg_depcon, "    checking Breaks");
+
+  breaks_check_target(aemsgs, &ok, pkg, pkg->set, NULL);
+
+  for (dep= pkg->installed.depends; dep; dep= dep->next) {
+    if (dep->type != dep_provides) continue;
+    virtbroken = dep->list;
+    debug(dbg_depcondetail, "     checking virtbroken %s", virtbroken->ed->name);
+    breaks_check_target(aemsgs, &ok, pkg, virtbroken->ed, virtbroken);
+  }
+  return ok;
+}
+
+/*
+ * Checks [Pre]-Depends only.
+ */
+enum dep_check
+dependencies_ok(struct pkginfo *pkg, struct pkginfo *removing,
+                struct varbuf *aemsgs)
+{
+  /* Valid values: 2 = ok, 1 = defer, 0 = halt. */
+  enum dep_check ok;
+  /* Valid values: 0 = none, 1 = defer, 2 = withwarning, 3 = ok. */
+  enum found_status found, thisf;
+  int interestingwarnings;
+  bool matched, anycannotfixbytrig;
+  struct varbuf oemsgs = VARBUF_INIT;
+  struct dependency *dep;
+  struct deppossi *possi, *provider;
+  struct pkginfo *possfixbytrig, *canfixbytrig;
+
+  ok = DEP_CHECK_OK;
+  debug(dbg_depcon,"checking dependencies of %s (- %s)",
+        pkg_name(pkg, pnaw_always),
+        removing ? pkg_name(removing, pnaw_always) : "<none>");
+
+  anycannotfixbytrig = false;
+  canfixbytrig = NULL;
+  for (dep= pkg->installed.depends; dep; dep= dep->next) {
+    if (dep->type != dep_depends && dep->type != dep_predepends) continue;
+    debug(dbg_depcondetail,"  checking group ...");
+    matched = false;
+    interestingwarnings = 0;
+    varbuf_reset(&oemsgs);
+    found = FOUND_NONE;
+    possfixbytrig = NULL;
+    for (possi = dep->list; found != FOUND_OK && possi; possi = possi->next) {
+      struct deppossi_pkg_iterator *possi_iter;
+      struct pkginfo *pkg_pos;
+
+      debug(dbg_depcondetail,"    checking possibility  -> %s",possi->ed->name);
+      if (possi->cyclebreak) {
+        debug(dbg_depcondetail,"      break cycle so ok and found");
+        found = FOUND_OK;
+        break;
+      }
+
+      thisf = FOUND_NONE;
+      possi_iter = deppossi_pkg_iter_new(possi, wpb_installed);
+      while ((pkg_pos = deppossi_pkg_iter_next(possi_iter))) {
+        thisf = deppossi_ok_found(pkg_pos, pkg, removing, NULL,
+                                  &possfixbytrig, &matched, possi,
+                                  &interestingwarnings, &oemsgs);
+        if (thisf > found)
+          found = thisf;
+        if (found == FOUND_OK)
+          break;
+      }
+      deppossi_pkg_iter_free(possi_iter);
+
+      if (found != FOUND_OK) {
+        for (provider = possi->ed->depended.installed;
+             found != FOUND_OK && provider;
+             provider = provider->rev_next) {
+          if (provider->up->type != dep_provides)
+            continue;
+          debug(dbg_depcondetail, "     checking provider %s",
+                pkg_name(provider->up->up, pnaw_always));
+          if (!deparchsatisfied(&provider->up->up->installed, provider->arch,
+                                possi)) {
+            debug(dbg_depcondetail, "       provider does not satisfy arch");
+            continue;
+          }
+          thisf = deppossi_ok_found(provider->up->up, pkg, removing, provider,
+                                    &possfixbytrig, &matched, possi,
+                                    &interestingwarnings, &oemsgs);
+          if (thisf == FOUND_DEFER && provider->up->up == pkg && !removing) {
+            /* IOW, if the pkg satisfies its own dep (via a provide), then
+             * we let it pass, even if it isn't configured yet (as we're
+             * installing it). */
+             thisf = FOUND_OK;
+          }
+          if (thisf > found)
+            found = thisf;
+        }
+      }
+      debug(dbg_depcondetail,"    found %d",found);
+      if (thisf > found) found= thisf;
+    }
+    if (in_force(FORCE_DEPENDS)) {
+      thisf = found_forced_on(DEPEND_TRY_FORCE_DEPENDS);
+      if (thisf > found) {
+        found = thisf;
+        debug(dbg_depcondetail, "  rescued by force-depends, found %d", found);
+      }
+    }
+    debug(dbg_depcondetail, "  found %d matched %d possfixbytrig %s",
+          found, matched,
+          possfixbytrig ? pkg_name(possfixbytrig, pnaw_always) : "-");
+    if (removing && !matched) continue;
+    switch (found) {
+    case FOUND_NONE:
+      anycannotfixbytrig = true;
+      ok = DEP_CHECK_HALT;
+      /* Fall through. */
+    case FOUND_FORCED:
+      varbuf_add_str(aemsgs, " ");
+      varbuf_add_pkgbin_name(aemsgs, pkg, &pkg->installed, pnaw_nonambig);
+      varbuf_add_str(aemsgs, _(" depends on "));
+      varbufdependency(aemsgs, dep);
+      if (interestingwarnings) {
+        /* Don't print the line about the package to be removed if
+         * that's the only line. */
+        varbuf_end_str(&oemsgs);
+        varbuf_add_str(aemsgs, _("; however:\n"));
+        varbuf_add_varbuf(aemsgs, &oemsgs);
+      } else {
+        varbuf_add_str(aemsgs, ".\n");
+      }
+      break;
+    case FOUND_DEFER:
+      if (possfixbytrig)
+        canfixbytrig = possfixbytrig;
+      else
+        anycannotfixbytrig = true;
+      if (ok > DEP_CHECK_DEFER)
+        ok = DEP_CHECK_DEFER;
+      break;
+    case FOUND_OK:
+      break;
+    default:
+      internerr("unknown value for found '%d'", found);
+    }
+  }
+  if (ok == DEP_CHECK_HALT &&
+      (pkg->clientdata && pkg->clientdata->istobe == PKG_ISTOBE_REMOVE))
+    ok = DEP_CHECK_DEFER;
+  if (!anycannotfixbytrig && canfixbytrig)
+    progress_bytrigproc = canfixbytrig;
+
+  varbuf_destroy(&oemsgs);
+  debug(dbg_depcon,"ok %d msgs >>%.*s<<", ok, (int)aemsgs->used, aemsgs->buf);
+  return ok;
+}