commit 43cea6d5652b6b9e61ac6ecc69419c909b504f47

Author: Siddhesh Poyarekar <siddhesh@sourceware.org>

Date:   Mon Sep 13 20:48:35 2021 +0530

    iconvconfig: Fix behaviour with --prefix [BZ #28199]

    The consolidation of configuration parsing broke behaviour with

    --prefix, where the prefix bled into the modules cache.  Accept a

    prefix which, when non-NULL, is prepended to the path when looking for

    configuration files but only the original directory is added to the

    modules cache.

    This has no effect on the codegen of gconv_conf since it passes NULL.

    Reported-by: Patrick McCarty <patrick.mccarty@intel.com>

    Reported-by: Michael Hudson-Doyle <michael.hudson@canonical.com>

    Reviewed-by: Andreas Schwab <schwab@linux-m68k.org>

diff --git a/iconv/gconv_conf.c b/iconv/gconv_conf.c

index ce64faa928dc1c52..3f5a692f1510157c 100644

--- a/iconv/gconv_conf.c

+++ b/iconv/gconv_conf.c

@@ -476,7 +476,7 @@ __gconv_read_conf (void)

     __gconv_get_path ();

   for (cnt = 0; __gconv_path_elem[cnt].name != NULL; ++cnt)

-    gconv_parseconfdir (__gconv_path_elem[cnt].name,

+    gconv_parseconfdir (NULL, __gconv_path_elem[cnt].name,

 			__gconv_path_elem[cnt].len);

 #endif

diff --git a/iconv/gconv_parseconfdir.h b/iconv/gconv_parseconfdir.h

index e4c3c16d1f96ce0c..433aa18bab5083b0 100644

--- a/iconv/gconv_parseconfdir.h

+++ b/iconv/gconv_parseconfdir.h

@@ -39,7 +39,6 @@

 /* Name of the file containing the module information in the directories

    along the path.  */

 static const char gconv_conf_filename[] = "gconv-modules";

-static const char gconv_conf_dirname[] = "gconv-modules.d";

 static void add_alias (char *);

 static void add_module (char *, const char *, size_t, int);

@@ -110,19 +109,28 @@ read_conf_file (const char *filename, const char *directory, size_t dir_len)

   return true;

 }

+/* Prefix DIR (with length DIR_LEN) with PREFIX if the latter is non-NULL and

+   parse configuration in it.  */

+

 static __always_inline bool

-gconv_parseconfdir (const char *dir, size_t dir_len)

+gconv_parseconfdir (const char *prefix, const char *dir, size_t dir_len)

 {

-  /* No slash needs to be inserted between dir and gconv_conf_filename;

-     dir already ends in a slash.  */

-  char *buf = malloc (dir_len + sizeof (gconv_conf_dirname));

+  /* No slash needs to be inserted between dir and gconv_conf_filename; dir

+     already ends in a slash.  The additional 2 is to accommodate the ".d"

+     when looking for configuration files in gconv-modules.d.  */

+  size_t buflen = dir_len + sizeof (gconv_conf_filename) + 2;

+  char *buf = malloc (buflen + (prefix != NULL ? strlen (prefix) : 0));

+  char *cp = buf;

   bool found = false;

   if (buf == NULL)

     return false;

-  char *cp = mempcpy (mempcpy (buf, dir, dir_len), gconv_conf_filename,

-		      sizeof (gconv_conf_filename));

+  if (prefix != NULL)

+    cp = stpcpy (cp, prefix);

+

+  cp = mempcpy (mempcpy (cp, dir, dir_len), gconv_conf_filename,

+		sizeof (gconv_conf_filename));

   /* Read the gconv-modules configuration file first.  */

   found = read_conf_file (buf, dir, dir_len);

diff --git a/iconv/iconvconfig.c b/iconv/iconvconfig.c

index 777da870d2f8e99a..b1fd4100b5cbc9d2 100644

--- a/iconv/iconvconfig.c

+++ b/iconv/iconvconfig.c

@@ -653,13 +653,21 @@ add_module (char *rp, const char *directory,

 static int

 handle_dir (const char *dir)

 {

+  char *newp = NULL;

   size_t dirlen = strlen (dir);

   bool found = false;

-  char *fulldir = xasprintf ("%s%s%s", dir[0] == '/' ? prefix : "",

-			     dir, dir[dirlen - 1] != '/' ? "/" : "");

+  /* End directory path with a '/' if it doesn't already.  */

+  if (dir[dirlen - 1] != '/')

+    {

+      newp = xmalloc (dirlen + 2);

+      memcpy (newp, dir, dirlen);

+      newp[dirlen++] = '/';

+      newp[dirlen] = '\0';

+      dir = newp;

+    }

-  found = gconv_parseconfdir (fulldir, strlen (fulldir));

+  found = gconv_parseconfdir (dir[0] == '/' ? prefix : NULL, dir, dirlen);

   if (!found)

     {

@@ -671,7 +679,7 @@ handle_dir (const char *dir)

 	     "configuration files with names ending in .conf.");

     }

-  free (fulldir);

+  free (newp);

   return found ? 0 : 1;

 }