[Emacs-diffs] /srv/bzr/emacs/trunk r107337: Protect fileio.c primitives against invalid file handler return values.

[Chong Yidong]

------------------------------------------------------------
revno: 107337
fixes bug(s): http://debbugs.gnu.org/10845
committer: Chong Yidong <address@hidden>
branch nick: trunk
timestamp: Sun 2012-02-19 17:58:23 +0800
message:
  Protect fileio.c primitives against invalid file handler return values.
  
  * src/fileio.c (Ffile_name_directory, Ffile_name_nondirectory)
  (Funhandled_file_name_directory, Ffile_name_as_directory)
  (Fdirectory_file_name, Fexpand_file_name)
  (Fsubstitute_in_file_name): Protect against invalid file
  handler return values.
modified:
  src/ChangeLog
  src/fileio.c

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2012-02-18 16:54:12 +0000
+++ b/src/ChangeLog     2012-02-19 09:58:23 +0000
@@ -1,3 +1,11 @@
+2012-02-19  Chong Yidong  <address@hidden>
+
+       * fileio.c (Ffile_name_directory, Ffile_name_nondirectory)
+       (Funhandled_file_name_directory, Ffile_name_as_directory)
+       (Fdirectory_file_name, Fexpand_file_name)
+       (Fsubstitute_in_file_name): Protect against invalid file handler
+       return values (Bug#10845).
+
 2012-02-18  Eli Zaretskii  <address@hidden>
 
        * .gdbinit (pitx): Fix incorrect references to fields of the

=== modified file 'src/fileio.c'
--- a/src/fileio.c      2012-01-19 07:21:25 +0000
+++ b/src/fileio.c      2012-02-19 09:58:23 +0000
@@ -328,7 +328,11 @@
      call the corresponding file handler.  */
   handler = Ffind_file_name_handler (filename, Qfile_name_directory);
   if (!NILP (handler))
-    return call2 (handler, Qfile_name_directory, filename);
+    {
+      Lisp_Object handled_name = call2 (handler, Qfile_name_directory,
+                                       filename);
+      return STRINGP (handled_name) ? handled_name : Qnil;
+    }
 
   filename = FILE_SYSTEM_CASE (filename);
 #ifdef DOS_NT
@@ -397,7 +401,13 @@
      call the corresponding file handler.  */
   handler = Ffind_file_name_handler (filename, Qfile_name_nondirectory);
   if (!NILP (handler))
-    return call2 (handler, Qfile_name_nondirectory, filename);
+    {
+      Lisp_Object handled_name = call2 (handler, Qfile_name_nondirectory,
+                                       filename);
+      if (STRINGP (handled_name))
+       return handled_name;
+      error ("Invalid handler in `file-name-handler-alist'");
+    }
 
   beg = SSDATA (filename);
   end = p = beg + SBYTES (filename);
@@ -434,7 +444,11 @@
      call the corresponding file handler.  */
   handler = Ffind_file_name_handler (filename, Qunhandled_file_name_directory);
   if (!NILP (handler))
-    return call2 (handler, Qunhandled_file_name_directory, filename);
+    {
+      Lisp_Object handled_name = call2 (handler, 
Qunhandled_file_name_directory,
+                                       filename);
+      return STRINGP (handled_name) ? handled_name : Qnil;
+    }
 
   return Ffile_name_directory (filename);
 }
@@ -488,7 +502,13 @@
      call the corresponding file handler.  */
   handler = Ffind_file_name_handler (file, Qfile_name_as_directory);
   if (!NILP (handler))
-    return call2 (handler, Qfile_name_as_directory, file);
+    {
+      Lisp_Object handled_name = call2 (handler, Qfile_name_as_directory,
+                                       file);
+      if (STRINGP (handled_name))
+       return handled_name;
+      error ("Invalid handler in `file-name-handler-alist'");
+    }
 
   buf = (char *) alloca (SBYTES (file) + 10);
   file_name_as_directory (buf, SSDATA (file));
@@ -547,7 +567,13 @@
      call the corresponding file handler.  */
   handler = Ffind_file_name_handler (directory, Qdirectory_file_name);
   if (!NILP (handler))
-    return call2 (handler, Qdirectory_file_name, directory);
+    {
+      Lisp_Object handled_name = call2 (handler, Qdirectory_file_name,
+                                       directory);
+      if (STRINGP (handled_name))
+       return handled_name;
+      error ("Invalid handler in `file-name-handler-alist'");
+    }
 
   buf = (char *) alloca (SBYTES (directory) + 20);
   directory_file_name (SSDATA (directory), buf);
@@ -747,7 +773,7 @@
   int is_escaped = 0;
 #endif /* DOS_NT */
   ptrdiff_t length;
-  Lisp_Object handler, result;
+  Lisp_Object handler, result, handled_name;
   int multibyte;
   Lisp_Object hdir;
 
@@ -757,7 +783,14 @@
      call the corresponding file handler.  */
   handler = Ffind_file_name_handler (name, Qexpand_file_name);
   if (!NILP (handler))
-    return call3 (handler, Qexpand_file_name, name, default_directory);
+    {
+      handled_name = call3 (handler, Qexpand_file_name,
+                           name, default_directory);
+      if (STRINGP (handled_name))
+       return handled_name;
+      error ("Invalid handler in `file-name-handler-alist'");
+    }
+
 
   /* Use the buffer's default-directory if DEFAULT_DIRECTORY is omitted.  */
   if (NILP (default_directory))
@@ -783,7 +816,13 @@
     {
       handler = Ffind_file_name_handler (default_directory, Qexpand_file_name);
       if (!NILP (handler))
-       return call3 (handler, Qexpand_file_name, name, default_directory);
+       {
+         handled_name = call3 (handler, Qexpand_file_name,
+                               name, default_directory);
+         if (STRINGP (handled_name))
+           return handled_name;
+         error ("Invalid handler in `file-name-handler-alist'");
+       }
     }
 
   {
@@ -1284,7 +1323,13 @@
      to be expanded again. */
   handler = Ffind_file_name_handler (result, Qexpand_file_name);
   if (!NILP (handler))
-    return call3 (handler, Qexpand_file_name, result, default_directory);
+    {
+      handled_name = call3 (handler, Qexpand_file_name,
+                           result, default_directory);
+      if (STRINGP (handled_name))
+       return handled_name;
+      error ("Invalid handler in `file-name-handler-alist'");
+    }
 
   return result;
 }
@@ -1537,7 +1582,13 @@
      call the corresponding file handler.  */
   handler = Ffind_file_name_handler (filename, Qsubstitute_in_file_name);
   if (!NILP (handler))
-    return call2 (handler, Qsubstitute_in_file_name, filename);
+    {
+      Lisp_Object handled_name = call2 (handler, Qsubstitute_in_file_name,
+                                       filename);
+      if (STRINGP (handled_name))
+       return handled_name;
+      error ("Invalid handler in `file-name-handler-alist'");
+    }
 
   /* Always work on a copy of the string, in case GC happens during
      decode of environment variables, causing the original Lisp_String