Bugfixes in NLS code.

* libmailutils/base/lcall.c (mu_lc_all_free): Use str->flags to
determine what fields need to be freed.
(mu_parse_lc_all): Force retrieving language and territory if charset
is requested.  Use this to provide a default value, in case charset cannot
be determined.  Deallocate the surplus data afterwards.
* libmailutils/base/locale.c (mu_charset_lookup): Bugfix.
* mail/util.c (util_rfc2047_decode): Avoid memory leak.

@@ -31,6 +31,8 @@ _parse_lc_all (const char *arg, struct mu_lc_all *str, int flags)
   char *s;
   size_t n;
   
+  str->flags = 0;
+  
   n = strcspn (arg, "_.@");
   if (flags & MU_LC_LANG)
     {
@@ -103,17 +105,22 @@ _parse_lc_all (const char *arg, struct mu_lc_all *str, int flags)
 void
 mu_lc_all_free (struct mu_lc_all *str)
 {
-  free (str->language);
-  free (str->territory);
-  free (str->charset);
-  free (str->modifier);
+  if (str->flags & MU_LC_LANG)
+    free (str->language);
+  if (str->flags & MU_LC_TERR)
+    free (str->territory);
+  if (str->flags & MU_LC_CSET)
+    free (str->charset);
+  if (str->flags & MU_LC_MOD)
+    free (str->modifier);
+  str->flags = 0;
 }
 
 int
 mu_parse_lc_all (const char *arg, struct mu_lc_all *str, int flags)
 {
   int rc;
-
+  
   memset (str, 0, sizeof (str[0]));
   if (!arg)
     {
@@ -125,18 +132,60 @@ mu_parse_lc_all (const char *arg, struct mu_lc_all *str, int flags)
 	}
       return 0;
     }
-  
-  rc = _parse_lc_all (arg, str, flags);
-  if (rc == 0 && !str->charset)
+
+  /* If charset is requested (MU_LC_CSET), request also language and
+     territory.  These will be used if ARG doesn't provide the charset
+     information.  In any case, the surplus data will be discarded before
+     returning. */
+  rc = _parse_lc_all (arg, str,
+		      (flags & MU_LC_CSET)
+		        ? (flags | MU_LC_LANG | MU_LC_TERR)
+		        : flags); 
+  if (rc == 0 && (flags & MU_LC_CSET))
     {
-      const char *charset = mu_charset_lookup (str->language, str->territory);
-      if (charset)
+      if (!str->charset)
+	{
+	  /* The caller requested charset, but we're unable to satisfy
+	     the request based on the ARG only.  Try the charset table
+	     lookup. */
+	  const char *charset =
+	    mu_charset_lookup (str->language, str->territory);
+	  if (charset)
+	    {
+	      /* Found it.  Fill in the charset field. */
+	      str->charset = strdup (charset);
+	      if (!str->charset)
+		{
+		  rc = ENOMEM;
+		  goto err;
+		}
+	      str->flags |= MU_LC_CSET;
+	    }
+	}
+
+      /* The STR struct most probably contains data not requested by
+	 the caller.  First, see what these are.  The following leaves
+	 in FLAGS only those bits that weren't requested, but were filled
+	 in just in case: */
+      flags = ~flags & str->flags;
+
+      /* Free the surplus data and clear the corresponding flag bits. */
+      if (flags & MU_LC_LANG)
 	{
-	  str->charset = strdup (charset);
-	  if (!str->charset)
-	    rc = ENOMEM;
+	  free (str->language);
+	  str->language = NULL;
+	  str->flags &= ~MU_LC_LANG;
+	}
+      
+      if (flags & MU_LC_TERR)
+	{
+	  free (str->territory);
+	  str->territory = NULL;
+	  str->flags &= ~MU_LC_TERR;
 	}
     }
+
+ err:
   if (rc)
     mu_lc_all_free (str);
   return rc;

@@ -235,7 +235,7 @@ mu_charset_lookup (char *lang, char *terr)
     if (mu_c_strcasecmp (p->lang, lang) == 0
 	&& (terr == NULL 
 	    || p->terr == NULL
-	    || !mu_c_strcasecmp (p->terr, terr) == 0))
+	    || mu_c_strcasecmp (p->terr, terr) == 0))
       return p->charset;
   return NULL;
 }

@@ -1051,31 +1051,19 @@ util_rfc2047_decode (char **value)
   char *charset = NULL;
   char *tmp;
   int rc;
+  struct mu_lc_all lc_all = { .flags = 0 };
 
   if (!*value || mailvar_get (&charset, "charset", mailvar_type_string, 0))
     return;
 
   if (mu_c_strcasecmp (charset, "auto") == 0)
     {
-      static char *saved_charset;
+      tmp = getenv ("LC_ALL");
+      if (!tmp)
+	tmp = getenv ("LANG");
 
-      if (!saved_charset)
-	{
-	  /* Try to deduce the charset from LC_ALL or LANG variables */
-
-	  tmp = getenv ("LC_ALL");
-	  if (!tmp)
-	    tmp = getenv ("LANG");
-
-	  if (tmp)
-	    {
-	      struct mu_lc_all lc_all;
-	      
-	      if (mu_parse_lc_all (tmp, &lc_all, MU_LC_CSET) == 0)
-		saved_charset = lc_all.charset;
-	    }
-	}
-      charset = saved_charset; /* NOTE: a minor memory leak */
+      if (tmp && mu_parse_lc_all (tmp, &lc_all, MU_LC_CSET) == 0)
+	charset = lc_all.charset;		  
     }
 
   if (!charset)
@@ -1092,6 +1080,8 @@ util_rfc2047_decode (char **value)
       free (*value);
       *value = tmp;
     }
+  if (lc_all.flags)
+    mu_lc_all_free (&lc_all);
 }
 
 const char *