[PATCH 1/2] helpers: Save a copy to the trapped error, not pointer

[Daniel Stone]

SetErrorTrap/ReleaseErrorTrap were storing a pointer to the error,
rather than a copy of it.  It was pretty liable to getting trashed, so
instead store a copy of our error.

Signed-off-by: Daniel Stone <daniel at fooishbar.org>
---
 tests/common/helpers.cpp |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/tests/common/helpers.cpp b/tests/common/helpers.cpp
index f48a134..3803d26 100644
--- a/tests/common/helpers.cpp
+++ b/tests/common/helpers.cpp
@@ -132,9 +132,9 @@ void DeviceSetEnabled(Display *dpy, int deviceid, bool enabled)
 /* Basic error trapping */
 static struct {
     bool is_trapping;
-    XErrorEvent *error;
+    XErrorEvent error;
     XErrorHandler prev_error_handler;
-} trap_state = { False, NULL, NULL };
+} trap_state;
 
 static int
 ErrorHandler(Display *dpy,
@@ -143,7 +143,7 @@ ErrorHandler(Display *dpy,
     if (!trap_state.is_trapping)
         ADD_FAILURE() << "Error trap received error while not trapping. WTF?";
 
-    trap_state.error = error;
+    trap_state.error = *error;
     return 0;
 }
 
@@ -154,6 +154,7 @@ void SetErrorTrap(Display *dpy) {
     XSync(dpy, False);
     trap_state.prev_error_handler = XSetErrorHandler(ErrorHandler);
     trap_state.is_trapping = True;
+    memset(&trap_state.error, 0, sizeof(trap_state.error));
 }
 
 XErrorEvent * ReleaseErrorTrap(Display *dpy) {
@@ -164,8 +165,7 @@ XErrorEvent * ReleaseErrorTrap(Display *dpy) {
     XSetErrorHandler(trap_state.prev_error_handler);
     trap_state.prev_error_handler = NULL;
 
-    XErrorEvent *error = trap_state.error;
-    trap_state.error = NULL;
+    XErrorEvent *error = &trap_state.error;
     trap_state.is_trapping = False;
     return error;
 }
-- 
1.7.10.4