[gnome-control-center/gnome-3-34] display: Fix the resolution going to be tested

[Robert Ancell <rancell src gnome org>]

commit 4cde93e076fa7d1bbfe6598f2fbe5a19825add41
Author: Jian-Hong Pan <jian-hong endlessm com>
Date:   Tue Mar 10 16:39:35 2020 +0800

    display: Fix the resolution going to be tested
    
    Gnome-control-center checks the display modes by
    cc_display_config_is_scaled_mode_valid()
      ...
      cc_display_config_dbus_is_scaled_mode_valid()
    to exclude unusable low resolutions.
    
    However, it is the current using resolution that going to be tested by
    is_scaled_mode_allowed() in is_scale_allowed_by_active_monitors(), if it
    is global scaled required or configured as cloning mode originally.
    Therefor, it will check current using resolution again and again,
    instead of the enumerated one. This leads gnome-control-center building
    wrong resolution list on the panel.
    
    This patch replaces the current mode with the enumerated mode to have
    the correct resolution to be tested by is_scaled_mode_allowed().
    
    Fixes #903

 panels/display/cc-display-config-dbus.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/panels/display/cc-display-config-dbus.c b/panels/display/cc-display-config-dbus.c
index 81b2c46f7..aa7c673be 100644
--- a/panels/display/cc-display-config-dbus.c
+++ b/panels/display/cc-display-config-dbus.c
@@ -1227,6 +1227,7 @@ is_scaled_mode_allowed (CcDisplayConfigDBus *self,
 
 static gboolean
 is_scale_allowed_by_active_monitors (CcDisplayConfigDBus *self,
+                                     CcDisplayMode       *mode,
                                      double               scale)
 {
   GList *l;
@@ -1238,7 +1239,7 @@ is_scale_allowed_by_active_monitors (CcDisplayConfigDBus *self,
       if (!cc_display_monitor_is_active (CC_DISPLAY_MONITOR (m)))
         continue;
 
-      if (!is_scaled_mode_allowed (self, m->current_mode, scale))
+      if (!is_scaled_mode_allowed (self, mode, scale))
         return FALSE;
     }
 
@@ -1266,7 +1267,7 @@ cc_display_config_dbus_is_scaled_mode_valid (CcDisplayConfig *pself,
   CcDisplayConfigDBus *self = CC_DISPLAY_CONFIG_DBUS (pself);
 
   if (self->global_scale_required || cc_display_config_is_cloning (pself))
-    return is_scale_allowed_by_active_monitors (self, scale);
+    return is_scale_allowed_by_active_monitors (self, mode, scale);
 
   return is_scaled_mode_allowed (self, mode, scale);
 }