make_and_run_test_nodes: avoid undefined behaviour

In code that looks like n[i] = v(&i), where v increments i, C leaves it
undefined whether the old or new value of i is used to locate n[i].
As it happens, gcc used the pre-increment value of i, but MSVC
used the post-increment value.

Fix this by inserting a sequence point to disambiguate the intended order.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=69924
Reviewed-by: Chengwei Yang <chengwei.yang@intel.com>
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
[wrote commit message, fixed whitespace -smcv]
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>

diff --git a/dbus/dbus-marshal-recursive-util.c b/dbus/dbus-marshal-recursive-util.c
index 9512414..a2aaaf9 100644 (file)
--- a/dbus/dbus-marshal-recursive-util.c
+++ b/dbus/dbus-marshal-recursive-util.c
@@ -1785,10 +1785,13 @@ make_and_run_test_nodes (void)
   start_next_test ("All values in one big toplevel %d iteration\n", 1);
   {
     TestTypeNode *nodes[N_VALUES];
+    TestTypeNode *node;
 
     i = 0;
-    while ((nodes[i] = value_generator (&i)))
-      ;
+    while ((node = value_generator (&i)))
+      {
+        nodes[i - 1] = node;
+      }
 
     run_test_nodes (nodes, N_VALUES);