[PATCH v2 01/10] Do not pass NULL to memcpy

[Tom Tromey]

-fsanitize=undefined pointed out a spot that passes NULL to memcpy,
which is undefined behavior according to the C standard.

gdb/ChangeLog
2018-08-29  Tom Tromey  <tom@tromey.com>

	* namespace.c (add_using_directive): Don't pass NULL to memcpy.
---
 gdb/ChangeLog   | 4 ++++
 gdb/namespace.c | 5 +++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/gdb/namespace.c b/gdb/namespace.c
index be998d9d491..85c0c4b14d7 100644
--- a/gdb/namespace.c
+++ b/gdb/namespace.c
@@ -111,8 +111,9 @@ add_using_directive (struct using_direct **using_directives,
   else
     newobj->declaration = declaration;
 
-  memcpy (newobj->excludes, excludes.data (),
-	  excludes.size () * sizeof (*newobj->excludes));
+  if (!excludes.empty ())
+    memcpy (newobj->excludes, excludes.data (),
+	    excludes.size () * sizeof (*newobj->excludes));
   newobj->excludes[excludes.size ()] = NULL;
 
   newobj->next = *using_directives;
-- 
2.13.6