[mutter] screen-cast-stream-src: Don't throttle if max framerate is 1/0

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 96dd794fd18ac2650d6186de5c62da7051f0ce92
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue May 12 08:52:01 2020 +0200

    screen-cast-stream-src: Don't throttle if max framerate is 1/0
    
    The max framerate 1/0 means variable without any particular max, so
    don't throttle if that was set.
    
    Not doing this would end up with a floating point exception.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1251

 src/backends/meta-screen-cast-stream-src.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/src/backends/meta-screen-cast-stream-src.c b/src/backends/meta-screen-cast-stream-src.c
index e63f5ddbb..544ed27a3 100644
--- a/src/backends/meta-screen-cast-stream-src.c
+++ b/src/backends/meta-screen-cast-stream-src.c
@@ -445,7 +445,8 @@ meta_screen_cast_stream_src_maybe_record_frame (MetaScreenCastStreamSrc *src)
   uint64_t now_us;
 
   now_us = g_get_monotonic_time ();
-  if (priv->last_frame_timestamp_us != 0 &&
+  if (priv->video_format.max_framerate.num > 0 &&
+      priv->last_frame_timestamp_us != 0 &&
       (now_us - priv->last_frame_timestamp_us <
        ((1000000 * priv->video_format.max_framerate.denom) /
         priv->video_format.max_framerate.num)))