[PATCH] randr: unref the provider shared pixmap the appropriate number of times

[Aaron Plattner]

When an RandR shared pixmap is created in rrCreateSharedPixmap, it has a refcnt
of 1.  Then, PixmapShareToSlave bumps the refcnt to 2.  However, there's no
corresponding PixmapUnshareFromSlave where the refcnt can be decreased again,
and there's no convenient common place where the refcnt can be decremented when
the slave pixmap is destroyed.

Fix this by just unreffing the pixmap twice in RRCrtcDetachScanoutPixmap.

Signed-off-by: Aaron Plattner <aplattner at nvidia.com>
---
 randr/rrcrtc.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/randr/rrcrtc.c b/randr/rrcrtc.c
index e82d050..6e2eca5 100644
--- a/randr/rrcrtc.c
+++ b/randr/rrcrtc.c
@@ -372,6 +372,11 @@ RRCrtcDetachScanoutPixmap(RRCrtcPtr crtc)
     ret = pScrPriv->rrCrtcSetScanoutPixmap(crtc, NULL);
     if (crtc->scanout_pixmap) {
         master->StopPixmapTracking(mscreenpix, crtc->scanout_pixmap);
+        /*
+         * Unref the pixmap twice: once for the original reference, and once
+         * for the reference implicitly added by PixmapShareToSlave.
+         */
+        master->DestroyPixmap(crtc->scanout_pixmap->master_pixmap);
         master->DestroyPixmap(crtc->scanout_pixmap->master_pixmap);
         crtc->pScreen->DestroyPixmap(crtc->scanout_pixmap);
     }
-- 
1.8.1.1