glx: Optimize out no-op make current calls

This make a lot more sense now that we might have to recreate the
glx drawables for legacy code paths.

diff --git a/src/glx/glxcurrent.c b/src/glx/glxcurrent.c
index 0d359f72b4adb6aca0519abe7ccd49bb53d77b44..36317383544240ce1cbad2a423473dd126d30cd4 100644 (file)
--- a/src/glx/glxcurrent.c
+++ b/src/glx/glxcurrent.c
@@ -242,6 +242,10 @@ MakeContextCurrent(Display * dpy, GLXDrawable draw,
       return False;
    }
 
+   if (oldGC == gc &&
+       gc->currentDrawable == draw && gc->currentReadable == read)
+      return True;
+
    if (oldGC != &dummyContext) {
       oldGC->vtable->unbind(oldGC, gc);
       oldGC->currentDpy = 0;