re PR preprocessor/51061 (Deprecated -I- option causes segfault)

2011-11-09  Paolo Carlini  <paolo.carlini@oracle.com>

	PR preprocessor/51061
	* incpath.c (merge_include_chains): Make sure to not pass null
	pointers to free_path.

From-SVN: r181216

gcc/ChangeLog

 2011-11-09  Paolo Carlini  <paolo.carlini@oracle.com>
 
+	PR preprocessor/51061
+	* incpath.c (merge_include_chains): Make sure to not pass null
+	pointers to free_path.
+
+2011-11-09  Paolo Carlini  <paolo.carlini@oracle.com>
+
 	* doc/invoke.texi ([Option Summary, C++ Language Options]):
 	Add -Wzero-as-null-pointer-constant.
 

gcc/incpath.c

@@ -362,7 +362,9 @@ merge_include_chains (const char *sysroot, cpp_reader *pfile, int verbose)
 void
 split_quote_chain (void)
 {
+  if (heads[QUOTE])
     free_path (heads[QUOTE], REASON_QUIET);
+  if (tails[QUOTE])
     free_path (tails[QUOTE], REASON_QUIET);
   heads[QUOTE] = heads[BRACKET];
   tails[QUOTE] = tails[BRACKET];