From 65fca558848acd907483d3c85c7cd4db5560f1b4 Mon Sep 17 00:00:00 2001 From: Radek Doulik Date: Tue, 13 Aug 2013 08:45:47 +0200 Subject: xnest: Ignore GetImage() error in xnestGetImage() When an Xnest instance is not viewable it will crash when a client in that instance calls GetImage. This is because the Xnest server will itself receives a BadMatch error. This patch ignores the error. The application which has requested the image will receive garbage - this however is fully legal according to the specs as obscured areas will always contain garbage if there isn't some sort of backing store as discussed in https://bugs.freedesktop.org/show_bug.cgi?id=9488 The applied patch is a version from Dadek Doulik. v2: Call XSync() before changing error handlers as suggested by Daniel Stone . Reviewed-by: Daniel Stone Signed-off-by: Egbert Eich --- hw/xnest/GCOps.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/hw/xnest/GCOps.c b/hw/xnest/GCOps.c index e26a1363b..7b1956de0 100644 --- a/hw/xnest/GCOps.c +++ b/hw/xnest/GCOps.c @@ -94,15 +94,29 @@ xnestPutImage(DrawablePtr pDrawable, GCPtr pGC, int depth, int x, int y, } } +static int +xnestIgnoreErrorHandler (Display *display, + XErrorEvent *event) +{ + return False; /* return value is ignored */ +} + void xnestGetImage(DrawablePtr pDrawable, int x, int y, int w, int h, unsigned int format, unsigned long planeMask, char *pImage) { XImage *ximage; int length; + int (*old_handler)(Display*, XErrorEvent*); + + /* we may get BadMatch error when xnest window is minimized */ + XSync(xnestDisplay, False); + old_handler = XSetErrorHandler (xnestIgnoreErrorHandler); ximage = XGetImage(xnestDisplay, xnestDrawable(pDrawable), x, y, w, h, planeMask, format); + XSync(xnestDisplay, False); + XSetErrorHandler(old_handler); if (ximage) { length = ximage->bytes_per_line * ximage->height; -- cgit v1.2.3