Fix NULL filename handling

The previous commit introduced a regression as some Ada tests end up passing
NULL as the filename to remap_filename.  Handle this as before to fix them.

gcc/
	* file-prefix-map.cc (remap_filename): Handle NULL filenames.

diff --git a/gcc/file-prefix-map.cc b/gcc/file-prefix-map.cc
index 439586bd2b5527a6ab368b7d3d50d3cb3e5483ee..40b10edcf928cafdb93bd56f5e346a1beeba8397 100644 (file)
--- a/gcc/file-prefix-map.cc
+++ b/gcc/file-prefix-map.cc
@@ -73,7 +73,7 @@ remap_filename (file_prefix_map *maps, const char *filename)
   char *realname;
   size_t name_len;
 
-  if (lbasename (filename) == filename)
+  if (!filename || lbasename (filename) == filename)
     return filename;
 
   realname = lrealpath (filename);