check if ext->name is null before strcmp()
diff --git a/src/mesa/drivers/x11/fakeglx.c b/src/mesa/drivers/x11/fakeglx.c
index 7f132eb..bc779a9 100644
--- a/src/mesa/drivers/x11/fakeglx.c
+++ b/src/mesa/drivers/x11/fakeglx.c
@@ -961,7 +961,7 @@
 {
    _XExtension *ext;
    for (ext = dpy->ext_procs; ext; ext = ext->next) {
-      if (strcmp(ext->name, extName) == 0) {
+      if (ext->name && strcmp(ext->name, extName) == 0) {
          return ext;
       }
    }