[PATCH v2] dix: don't XWarpPointer through the last slave anymore (#38313)

[Peter Hutterer]

This line was introduced pre-1.6 to fix Bug 19297. The effect of warping
through the VCP then was that if a device had custom valuator ranges, the
warp position would be wrong. The better device for this effect is the the
XTest device.

This fixes a server crash where the lastSlave is a pointer device without
valuators (Bug 38313#0).

And while we're at it, make sure the Xinerama code-path does the same.

X.Org Bug 38313 <http://bugs.freedesktop.org/show_bug.cgi?id=38313>

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
changes to v1:
- use the XTest device, not the VCP directly
- fix up xinerama to do the same

 dix/events.c |   21 ++++++++++++++-------
 1 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/dix/events.c b/dix/events.c
index d78989d..9596481 100644
--- a/dix/events.c
+++ b/dix/events.c
@@ -3377,16 +3377,21 @@ XineramaWarpPointer(ClientPtr client)
 {
     WindowPtr	dest = NULL;
     int		x, y, rc;
-    SpritePtr   pSprite = PickPointer(client)->spriteInfo->sprite;
+    DeviceIntPtr dev;
+    SpritePtr   pSprite;
 
     REQUEST(xWarpPointerReq);
 
-
     if (stuff->dstWid != None) {
 	rc = dixLookupWindow(&dest, stuff->dstWid, client, DixReadAccess);
 	if (rc != Success)
 	    return rc;
     }
+
+    /* Post through the XTest device */
+    dev = PickPointer(client);
+    dev = GetXTestDevice(dev);
+    pSprite = dev->spriteInfo->sprite;
     x = pSprite->hotPhys.x;
     y = pSprite->hotPhys.y;
 
@@ -3436,9 +3441,9 @@ XineramaWarpPointer(ClientPtr client)
     else if (y >= pSprite->physLimits.y2)
 	y = pSprite->physLimits.y2 - 1;
     if (pSprite->hotShape)
-	ConfineToShape(PickPointer(client), pSprite->hotShape, &x, &y);
+	ConfineToShape(dev, pSprite->hotShape, &x, &y);
 
-    XineramaSetCursorPosition(PickPointer(client), x, y, TRUE);
+    XineramaSetCursorPosition(dev, x, y, TRUE);
 
     return Success;
 }
@@ -3456,7 +3461,7 @@ ProcWarpPointer(ClientPtr client)
     WindowPtr	dest = NULL;
     int		x, y, rc;
     ScreenPtr	newScreen;
-    DeviceIntPtr dev, tmp;
+    DeviceIntPtr dev, tmp, xtest_dev = NULL;
     SpritePtr   pSprite;
 
     REQUEST(xWarpPointerReq);
@@ -3469,11 +3474,13 @@ ProcWarpPointer(ClientPtr client)
 	    rc = XaceHook(XACE_DEVICE_ACCESS, client, dev, DixWriteAccess);
 	    if (rc != Success)
 		return rc;
+            if (IsXTestDevice(tmp, dev))
+                xtest_dev = tmp;
 	}
     }
 
-    if (dev->lastSlave)
-        dev = dev->lastSlave;
+    /* Use the XTest device to actually move the pointer */
+    dev = xtest_dev;
     pSprite = dev->spriteInfo->sprite;
 
 #ifdef PANORAMIX
-- 
1.7.6