Change reopen_exec_file to check result of stat

This seems to be a real bug found by -Wunused-but-set-variable.  If
"stat" fails for some reason, gdb would use the uninitialized "st".

2016-07-14  Tom Tromey  <tom@tromey.com>

	* corefile.c (reopen_exec_file): Only examine st.st_mtime if stat
	succeeded.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ba207ba949606565a6a0d0b1921b532b592e2f1f..cef090cc3dce267effa958c41b0cc97ece0fb1a2 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2016-07-14  Tom Tromey  <tom@tromey.com>
+
+       * corefile.c (reopen_exec_file): Only examine st.st_mtime if stat
+       succeeded.
+
 2016-07-13  Tom Tromey  <tom@tromey.com>
 
        PR python/15620, PR python/18620:

diff --git a/gdb/corefile.c b/gdb/corefile.c
index 6cc2afc49e816e2dbefe45266e2977df1a5e4176..64de931b167dbf59110a8a0970d1731e4325ee9a 100644 (file)
--- a/gdb/corefile.c
+++ b/gdb/corefile.c
@@ -144,7 +144,7 @@ reopen_exec_file (void)
   cleanups = make_cleanup (xfree, filename);
   res = stat (filename, &st);
 
-  if (exec_bfd_mtime && exec_bfd_mtime != st.st_mtime)
+  if (res == 0 && exec_bfd_mtime && exec_bfd_mtime != st.st_mtime)
     exec_file_attach (filename, 0);
   else
     /* If we accessed the file since last opening it, close it now;