[mutter] renderer-native: Fix page flip retry timeout calculation

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

commit 40e7e5d35646bbe2e79fd8bc0d32a3bd920e4673
Author: Jonas Ådahl <jadahl gmail com>
Date:   Fri Mar 22 18:54:20 2019 +0100

    renderer-native: Fix page flip retry timeout calculation
    
    It tried to add a (implicitly casted) float to a uint64_t, and due to
    floating point precision issues resulted in timestamps intended to be
    in the future to actually be in the past. Fix this by first casting the
    delay to an uint64_t, then add it to the time stamp.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/506

 src/backends/native/meta-renderer-native.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/backends/native/meta-renderer-native.c b/src/backends/native/meta-renderer-native.c
index e030e9518..d0de9d0d0 100644
--- a/src/backends/native/meta-renderer-native.c
+++ b/src/backends/native/meta-renderer-native.c
@@ -1576,7 +1576,7 @@ retry_page_flips (gpointer user_data)
           g_error_matches (error, G_IO_ERROR, G_IO_ERROR_BUSY))
         {
           retry_page_flip_data->retry_time_us +=
-            G_USEC_PER_SEC / crtc->current_mode->refresh_rate;
+            (uint64_t) (G_USEC_PER_SEC / crtc->current_mode->refresh_rate);
           l = l_next;
           continue;
         }
@@ -1660,7 +1660,7 @@ schedule_retry_page_flip (MetaOnscreenNative *onscreen_native,
 
   now_us = g_get_monotonic_time ();
   retry_time_us =
-    now_us + (G_USEC_PER_SEC / crtc->current_mode->refresh_rate);
+    now_us + (uint64_t) (G_USEC_PER_SEC / crtc->current_mode->refresh_rate);
 
   retry_page_flip_data = g_new0 (RetryPageFlipData, 1);
   retry_page_flip_data->crtc = crtc;