[PATCH v2 04/29] Core events: invert check for permission to copy key states

[Alan Coopersmith]

Always initialize to zero, and then if permission is granted, copy
the current key state maps.   Use memcpy instead of memmove for the
copy, since we're always copying to a newly allocated event on the
stack, so guaranteed not to overlap with the device map structure.

Signed-off-by: Alan Coopersmith <alan.coopersmith at oracle.com>
---
 dix/events.c |   18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/dix/events.c b/dix/events.c
index 7933749..6e4385a 100644
--- a/dix/events.c
+++ b/dix/events.c
@@ -4512,11 +4512,12 @@ CoreEnterLeaveEvent(DeviceIntPtr mouse,
     if ((type == EnterNotify) && (mask & KeymapStateMask)) {
         xKeymapEvent ke;
         ClientPtr client = grab ? rClient(grab) : wClient(pWin);
+        int rc;
 
-        if (XaceHook(XACE_DEVICE_ACCESS, client, keybd, DixReadAccess))
-            memset((char *) &ke.map[0], 0, 31);
-        else
-            memmove((char *) &ke.map[0], (char *) &keybd->key->down[1], 31);
+        memset((char *) &ke.map[0], 0, 31);
+        rc = XaceHook(XACE_DEVICE_ACCESS, client, keybd, DixReadAccess);
+        if (rc == Success)
+            memcpy((char *) &ke.map[0], (char *) &keybd->key->down[1], 31);
 
         ke.type = KeymapNotify;
         if (grab)
@@ -4617,11 +4618,12 @@ CoreFocusEvent(DeviceIntPtr dev, int type, int mode, int detail, WindowPtr pWin)
         ((pWin->eventMask | wOtherEventMasks(pWin)) & KeymapStateMask)) {
         xKeymapEvent ke;
         ClientPtr client = wClient(pWin);
+        int rc;
 
-        if (XaceHook(XACE_DEVICE_ACCESS, client, dev, DixReadAccess))
-            memset((char *) &ke.map[0], 0, 31);
-        else
-            memmove((char *) &ke.map[0], (char *) &dev->key->down[1], 31);
+        memset((char *) &ke.map[0], 0, 31);
+        rc = XaceHook(XACE_DEVICE_ACCESS, client, dev, DixReadAccess);
+        if (rc == Success)
+            memcpy((char *) &ke.map[0], (char *) &dev->key->down[1], 31);
 
         ke.type = KeymapNotify;
         DeliverEventsToWindow(dev, pWin, (xEvent *) &ke, 1,
-- 
1.7.9.2