mapi: Return NULL function pointers for GL_EXT_debug_marker

Mesa returns a stub function pointer to glAnything for years.
Android framework till API level 30 just uses function pointers
returned from eglGetProcAddress without checking if the underlying
extension is supported. If we return stub pointers for functions
in GL_EXT_debug_marker, Android just uses our stub functions instead
of its own stubs and then fail the dEQP. In the past, the issue
didn't show up because mesa only has limited slots and run out of slots
before Android calls eglGetProcAddress on functions inside
GL_EXT_debug_marker.

Signed-off-by: Lepton Wu <lepton@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5652>
diff --git a/src/mapi/mapi_glapi.c b/src/mapi/mapi_glapi.c
index 1cee148..21ca0a0 100644
--- a/src/mapi/mapi_glapi.c
+++ b/src/mapi/mapi_glapi.c
@@ -169,6 +169,15 @@
    return (alias) ? stub_get_slot(alias) : -1;
 }
 
+#if defined(ANDROID) && ANDROID_API_LEVEL <= 30
+static int is_debug_marker_func(const char *name)
+{
+   return (!strcmp(name, "InsertEventMarkerEXT") ||
+           !strcmp(name, "PushGroupMarkerEXT") ||
+           !strcmp(name, "PopGroupMarkerEXT"));
+}
+#endif
+
 static const struct mapi_stub *
 _glapi_get_stub(const char *name, int generate)
 {
@@ -179,7 +188,15 @@
    name += 2;
 
    stub = stub_find_public(name);
+#if defined(ANDROID) && ANDROID_API_LEVEL <= 30
+   /* Android framework till API Level 30 uses function pointers from
+    * eglGetProcAddress without checking GL_EXT_debug_marker.
+    * Make sure we don't return stub function pointers if we don't
+    * support GL_EXT_debug_marker */
+   if (!stub && !is_debug_marker_func(name))
+#else
    if (!stub)
+#endif
       stub = stub_find_dynamic(name, generate);
 
    return stub;