On 18/04/2017 22:08, Adam Jackson wrote:
On Tue, 2017-04-18 at 11:53 +0100, Jon Turney wrote:
This is possibly an actual bug in failing to check we successfully retrieved
the monitor size before using it to set the X screen size.
It is indeed.
@@ -261,6 +261,9 @@ winWindowProc(HWND hwnd, UINT message, WPARAM wParam,
LPARAM lParam)
ErrorF("Monitor number %d no longer exists!\n",
s_pScreenInfo->iMonitor);
}
+ ErrorF("QueryMonitor %d failed!\n",
+ s_pScreenInfo->iMonitor);
+
This is inside if (QueryMonitor()), which returns true most of the
time. It only returns false if the second argument is null (which it
won't ever be since it's on the stack), and also ignores the return
value from EnumDisplayMonitors. So basically you're now printing that
it fails on every call.
Oops!
But yes, even if I'd managed to correctly put this in an else clause,
this is pointless (and checking the return value of
EnumDisplayMonitors() turns out the be not very useful either, see
5940580f), so I'll drop that part, and maybe make a patch to make
QueryMonitor() less insane later...
Thanks for catching this.
Amended patch attached.
From 4df504fda1a4a913f803b50da8081fe39927f50a Mon Sep 17 00:00:00 2001
From: Jon Turney <[email protected]>
Date: Wed, 19 Apr 2017 13:30:27 +0100
Subject: [PATCH xserver 2/4] hw/xwin: Fix -Wmaybe-uninitialized warning in
winWindowProc
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
This is possibly an actual bug in failing to check we successfuly retrieved
the monitor size before using it to set the X screen size.
../hw/xwin/winwndproc.c: In function ‘winWindowProc’:
../hw/xwin/winwndproc.c:283:55: warning: ‘dwHeight’ may be used uninitialized
in this function [-Wmaybe-uninitialized]
../hw/xwin/winwndproc.c:240:32: note: ‘dwHeight’ was declared here
../hw/xwin/winwndproc.c:281:54: warning: ‘dwWidth’ may be used uninitialized in
this function [-Wmaybe-uninitialized]
../hw/xwin/winwndproc.c:240:23: note: ‘dwWidth’ was declared here
Signed-off-by: Jon Turney <[email protected]>
---
hw/xwin/winwndproc.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/hw/xwin/winwndproc.c b/hw/xwin/winwndproc.c
index 7236a95..ad9f1b3 100644
--- a/hw/xwin/winwndproc.c
+++ b/hw/xwin/winwndproc.c
@@ -237,7 +237,7 @@ winWindowProc(HWND hwnd, UINT message, WPARAM wParam,
LPARAM lParam)
fMultiWindow
#endif
)) {
- DWORD dwWidth, dwHeight;
+ DWORD dwWidth = 0, dwHeight = 0;
if (s_pScreenInfo->fMultipleMonitors) {
/* resize to new virtual desktop size */
@@ -273,8 +273,9 @@ winWindowProc(HWND hwnd, UINT message, WPARAM wParam,
LPARAM lParam)
*/
/* Set screen size to match new size, if it is different to
current */
- if ((s_pScreenInfo->dwWidth != dwWidth) ||
- (s_pScreenInfo->dwHeight != dwHeight)) {
+ if (((dwWidth != 0) && (dwHeight != 0)) &&
+ ((s_pScreenInfo->dwWidth != dwWidth) ||
+ (s_pScreenInfo->dwHeight != dwHeight))) {
winDoRandRScreenSetSize(s_pScreen,
dwWidth,
dwHeight,
--
2.8.3
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