argv.c (expandargv): Correct check for dynamically allocated argv.

2018-01-10  Daniel van Gerpen  <daniel@vangerpen.de>

	* argv.c (expandargv): Correct check for dynamically
	allocated argv.

From-SVN: r256460

libiberty/ChangeLog

+2018-01-10  Daniel van Gerpen  <daniel@vangerpen.de>
+
+	* argv.c (expandargv): Correct check for dynamically
+	allocated argv.
+
 2018-01-03  Jakub Jelinek  <jakub@redhat.com>
 
 	Update copyright years.

libiberty/argv.c

@@ -367,8 +367,8 @@ expandargv (int *argcp, char ***argvp)
 {
   /* The argument we are currently processing.  */
   int i = 0;
-  /* Non-zero if ***argvp has been dynamically allocated.  */
-  int argv_dynamic = 0;
+  /* To check if ***argvp has been dynamically allocated.  */
+  char ** const original_argv = *argvp;
   /* Limit the number of response files that we parse in order
      to prevent infinite recursion.  */
   unsigned int iteration_limit = 2000;
@@ -449,7 +449,7 @@ expandargv (int *argcp, char ***argvp)
 	/* Parse the string.  */
 	file_argv = buildargv (buffer);
       /* If *ARGVP is not already dynamically allocated, copy it.  */
-      if (!argv_dynamic)
+      if (*argvp == original_argv)
 	*argvp = dupargv (*argvp);
       /* Count the number of arguments.  */
       file_argc = 0;