glx: Make glXGetScreenDriver() work for DRI2

src/glx/x11/dri_glx.c

@@ -40,6 +40,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include "glxclient.h"
 #include "glcontextmodes.h"
 #include "xf86dri.h"
+#include "dri2.h"
 #include "sarea.h"
 #include <dlfcn.h>
 #include <sys/types.h>
@@ -77,10 +78,12 @@ static Bool driGetDriverName(Display *dpy, int scrNum, char **driverName)
 {
     int directCapable;
     Bool b;
+    int event, error;
     int driverMajor, driverMinor, driverPatch;
 
     *driverName = NULL;
 
+    if (XF86DRIQueryExtension(dpy, &event, &error)) { /* DRI1 */
 	if (!XF86DRIQueryDirectRenderingCapable(dpy, scrNum, &directCapable)) {
 	    ErrorMessageF("XF86DRIQueryDirectRenderingCapable failed\n");
 	    return False;
@@ -101,6 +104,17 @@ static Bool driGetDriverName(Display *dpy, int scrNum, char **driverName)
 		driverMajor, driverMinor, driverPatch, *driverName, scrNum);
 
 	return True;
+    } else if (DRI2QueryExtension(dpy, &event, &error)) { /* DRI2 */
+	char *dev;
+	Bool ret = DRI2Connect(dpy, RootWindow(dpy, scrNum), driverName, &dev);
+
+	if (ret)
+	    Xfree(dev);
+
+	return ret;
+    }
+
+    return False;
 }
 
 /*