Initialize extension with the right number of events.

If the server supports a lower XI version than the client, the Xlib-internal
event vector may be smashed. See libXext for more details.
http://cgit.freedesktop.org/xorg/lib/libXext/commit/?id=83fdb27df4ddc2fb088ddf2ec65f0db6b7c57287

This patch queries the server for the supported XI extension before
registering the extension with Xlib. The number of events registered depends
on the server version.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Julien Cristau <jcristau@debian.org>

1 files changed, 16 insertions, 8 deletions

diff --git a/src/XGetVers.c b/src/XGetVers.c
index 3b500ae..4718617 100644
--- a/src/XGetVers.c
+++ b/src/XGetVers.c
@@ -72,19 +72,15 @@ XGetExtensionVersion(register Display * dpy, _Xconst char *name)
     return (ext);
 }
 
-_X_HIDDEN XExtensionVersion *
-_XiGetExtensionVersion(register Display * dpy, _Xconst char *name,
-                       XExtDisplayInfo *info)
+_X_HIDDEN XExtensionVersion*
+_XiGetExtensionVersionRequest(Display *dpy, _Xconst char *name, int xi_opcode)
 {
     xGetExtensionVersionReq *req;
     xGetExtensionVersionReply rep;
     XExtensionVersion *ext;
 
-    if (_XiCheckExtInit(dpy, Dont_Check, info) == -1)
-	return ((XExtensionVersion *) NoSuchExtension);
-
     GetReq(GetExtensionVersion, req);
-    req->reqType = info->codes->major_opcode;
+    req->reqType = xi_opcode;
     req->ReqType = X_GetExtensionVersion;
     req->nbytes = strlen(name);
     req->length += (unsigned)(req->nbytes + 3) >> 2;
@@ -93,6 +89,7 @@ _XiGetExtensionVersion(register Display * dpy, _Xconst char *name,
     if (!_XReply(dpy, (xReply *) & rep, 0, xTrue)) {
 	return (XExtensionVersion *) NULL;
     }
+
     ext = (XExtensionVersion *) Xmalloc(sizeof(XExtensionVersion));
     if (ext) {
 	ext->present = rep.present;
@@ -101,5 +98,16 @@ _XiGetExtensionVersion(register Display * dpy, _Xconst char *name,
 	    ext->minor_version = rep.minor_version;
 	}
     }
-    return (ext);
+
+    return ext;
+}
+
+_X_HIDDEN XExtensionVersion *
+_XiGetExtensionVersion(register Display * dpy, _Xconst char *name,
+                       XExtDisplayInfo *info)
+{
+    if (_XiCheckExtInit(dpy, Dont_Check, info) == -1)
+	return ((XExtensionVersion *) NoSuchExtension);
+
+    return _XiGetExtensionVersionRequest(dpy, name, info->codes->major_opcode);
 }