[binutils-gdb] Fix possible bug when no args have been provided to the executable

[Sergio Durigan Junior <sergiodj at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=2f91880f3afb3cc521111dfcc99b214c77aa97a1

commit 2f91880f3afb3cc521111dfcc99b214c77aa97a1
Author: Sergio Durigan Junior <sergiodj@redhat.com>
Date:   Thu Jun 8 16:58:25 2017 -0400

    Fix possible bug when no args have been provided to the executable
    
    Hi,
    
    This bug is related to:
    
      <https://sourceware.org/ml/gdb-patches/2017-06/msg00216.html>
    
    On stringify_argv, we have to check if args[0] is not NULL before
    stringifying anything, otherwise we might do the wrong thing when
    trimming the "ret" string in the end.  args[0] will be NULL when no
    arguments are passed to the inferior that will be started.
    
    Checked in as obvious.
    
    gdb/ChangeLog:
    2017-06-08  Sergio Durigan Junior  <sergiodj@redhat.com>
    
    	* common/common-utils.c (stringify_argv): Check for "arg[0] !=
    	NULL".

Diff:
---
 gdb/ChangeLog             | 5 +++++
 gdb/common/common-utils.c | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 993fabe..5ebc7f8 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2017-06-08  Sergio Durigan Junior  <sergiodj@redhat.com>
+
+	* common/common-utils.c (stringify_argv): Check for "arg[0] !=
+	NULL".
+
 2017-06-08 Alan Hayward  <alan.hayward@arm.com>
 
 	* mn10300-tdep.c (MN10300_MAX_REGISTER_SIZE): Add.
diff --git a/gdb/common/common-utils.c b/gdb/common/common-utils.c
index 793ab3b..e75a1b9 100644
--- a/gdb/common/common-utils.c
+++ b/gdb/common/common-utils.c
@@ -337,7 +337,7 @@ stringify_argv (const std::vector<char *> &args)
 {
   std::string ret;
 
-  if (!args.empty ())
+  if (!args.empty () && args[0] != NULL)
     {
       for (auto s : args)
 	if (s != NULL)