I get an assertion failure in xcb_xlib_lock when calling XGetExtensionVersion 
in libXi (happens when starting any Qt application). Patch below fixes it.

diff --git a/src/XGetVers.c b/src/XGetVers.c
index 1f4fd7a..18dd6d8 100644
--- a/src/XGetVers.c
+++ b/src/XGetVers.c
@@ -67,10 +67,8 @@ XGetExtensionVersion(register Display *

     LockDisplay(dpy);
     ext = _XiGetExtensionVersion(dpy, name);
-    if (ext != (XExtensionVersion *) NoSuchExtension) {
-       UnlockDisplay(dpy);
-       SyncHandle();
-    }
+    UnlockDisplay(dpy);
+    SyncHandle();
     return (ext);
 }

@@ -80,7 +78,11 @@ _XiGetExtensionVersion(register Display
     xGetExtensionVersionReq *req;
     xGetExtensionVersionReply rep;
     XExtensionVersion *ext;
-    XExtDisplayInfo *info = XInput_find_display(dpy);
+    XExtDisplayInfo *info;
+
+    UnlockDisplay(dpy);
+    info = XInput_find_display(dpy);
+    LockDisplay(dpy);

     if (_XiCheckExtInit(dpy, Dont_Check) == -1)
        return ((XExtensionVersion *) NoSuchExtension);


Ok to commit?

Lars