[PATCH] expandargv: fix check for dynamic allocation of argument vector

[Daniel van Gerpen <daniel at vangerpen dot de>]

When the code interpolates the contents of response files, the
argument vector is reallocated to the new size. This only works
if it was dynamically allocated once before -- we do not want to
mess with the argv memory given to us by the init code.

The code tried to detect this with a flag, but that was never
written to, leading to multiple dynamic allocations -- one
for each response file.
---
 libiberty/argv.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/libiberty/argv.c b/libiberty/argv.c
index bdd4ace4cb6..fa88e50e894 100644
--- a/libiberty/argv.c
+++ b/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;
-- 
2.11.0