*** empty log message ***

[gnulib.git] / lib / localcharset.c

diff --git a/lib/localcharset.c b/lib/localcharset.c
index 0005910..932473c 100644 (file)
--- a/lib/localcharset.c
+++ b/lib/localcharset.c
@@ -23,9 +23,16 @@
 # include <config.h>
 #endif
 
-#include <stddef.h>
+#if HAVE_STDDEF_H
+# include <stddef.h>
+#endif
+
 #include <stdio.h>
-#include <string.h>
+#if HAVE_STRING_H
+# include <string.h>
+#else
+# include <strings.h>
+#endif
 #if HAVE_STDLIB_H
 # include <stdlib.h>
 #endif
@@ -38,9 +45,20 @@
 # endif
 #endif
 
-char *xmalloc ();
-char *xrealloc ();
+#ifndef DIRECTORY_SEPARATOR
+# define DIRECTORY_SEPARATOR '/'
+#endif
 
+#ifndef ISSLASH
+# define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR)
+#endif
+
+/* The following static variable is declared 'volatile' to avoid a
+   possible multithread problem in the function get_charset_aliases. If we
+   are running in a threaded environment, and if two threads initialize
+   'charset_aliases' simultaneously, both will produce the same value,
+   and everything will be ok if the two assignments to 'charset_aliases'
+   are atomic. But I don't know what will happen if the two assignments mix.  */
 /* Pointer to the contents of the charset.alias file, if it has already been
    read, else NULL.  Its format is:
    ALIAS_1 '\0' CANONICAL_1 '\0' ... ALIAS_n '\0' CANONICAL_n '\0' '\0'  */
@@ -56,10 +74,27 @@ get_charset_aliases ()
   if (cp == NULL)
     {
       FILE *fp;
+      const char *dir = LIBDIR;
+      const char *base = "charset.alias";
+      char *file_name;
+
+      /* Concatenate dir and base into freshly allocated file_name.  */
+      {
+       size_t dir_len = strlen (dir);
+       size_t base_len = strlen (base);
+       int add_slash = (dir_len > 0 && !ISSLASH (dir[dir_len - 1]));
+       file_name = (char *) malloc (dir_len + add_slash + base_len + 1);
+       if (file_name != NULL)
+         {
+           memcpy (file_name, dir, dir_len);
+           if (add_slash)
+             file_name[dir_len] = DIRECTORY_SEPARATOR;
+           memcpy (file_name + dir_len + add_slash, base, base_len + 1);
+         }
+      }
 
-      fp = fopen (LIBDIR "/" "charset.alias", "r");
-      if (fp == NULL)
-       /* File not found, treat it as empty.  */
+      if (file_name == NULL || (fp = fopen (file_name, "r")) == NULL)
+       /* Out of memory or file not found, treat it as empty.  */
        cp = "";
       else
        {
@@ -96,12 +131,18 @@ get_charset_aliases ()
              if (res_size == 0)
                {
                  res_size = l1 + 1 + l2 + 1;
-                 res_ptr = xmalloc (res_size + 1);
+                 res_ptr = malloc (res_size + 1);
                }
              else
                {
                  res_size += l1 + 1 + l2 + 1;
-                 res_ptr = xrealloc (res_ptr, res_size + 1);
+                 res_ptr = realloc (res_ptr, res_size + 1);
+               }
+             if (res_ptr == NULL)
+               {
+                 /* Out of memory. */
+                 res_size = 0;
+                 break;
                }
              strcpy (res_ptr + res_size - (l2 + 1) - (l1 + 1), buf1);
              strcpy (res_ptr + res_size - (l2 + 1), buf2);
@@ -117,6 +158,8 @@ get_charset_aliases ()
        }
 
       charset_aliases = cp;
+      if (file_name != NULL)
+       free (file_name);
     }
 
   return cp;
@@ -150,13 +193,13 @@ locale_charset ()
 # if HAVE_SETLOCALE
   locale = setlocale (LC_CTYPE, NULL);
 # endif
-  if (locale == NULL)
+  if (locale == NULL || locale[0] == '\0')
     {
       locale = getenv ("LC_ALL");
-      if (locale == NULL)
+      if (locale == NULL || locale[0] == '\0')
        {
          locale = getenv ("LC_CTYPE");
-         if (locale == NULL)
+         if (locale == NULL || locale[0] == '\0')
            locale = getenv ("LANG");
        }
     }
@@ -168,7 +211,7 @@ locale_charset ()
 
 #endif
 
-  if (codeset != NULL)
+  if (codeset != NULL && codeset[0] != '\0')
     {
       /* Resolve alias. */
       for (aliases = get_charset_aliases ();