[mutter] stack-tracker: Don't log warnings on race conditions

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

commit 53f61f3778a41bb2e316e55eb7e6dd864b3dd573
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue Jun 9 19:09:00 2020 +0200

    stack-tracker: Don't log warnings on race conditions
    
    X11 window stacking operations are by nature prone to race conditions.
    For example, we might queue a "raise above" operation, but before it
    actually takes place, the sibling the window was to be rased above, is
    withdrawn.
    
    In these cases we'd log warnings even though they are expected to
    happen. Downgrade these warnings to debug messages, only printed when
    MUTTER_VERBOSE is set.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1300

 src/core/stack-tracker.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)
---
diff --git a/src/core/stack-tracker.c b/src/core/stack-tracker.c
index 8d15b80c94..96ffabcee1 100644
--- a/src/core/stack-tracker.c
+++ b/src/core/stack-tracker.c
@@ -381,8 +381,9 @@ meta_stack_op_apply (MetaStackTracker *tracker,
         old_pos = find_window (stack, op->add.window);
         if (old_pos >= 0)
           {
-            g_warning ("STACK_OP_ADD: window %s already in stack",
-                       get_window_desc (tracker, op->add.window));
+            meta_topic (META_DEBUG_STACK,
+                        "STACK_OP_ADD: window %s already in stack",
+                        get_window_desc (tracker, op->add.window));
             return FALSE;
           }
 
@@ -400,8 +401,9 @@ meta_stack_op_apply (MetaStackTracker *tracker,
         old_pos = find_window (stack, op->remove.window);
         if (old_pos < 0)
           {
-            g_warning ("STACK_OP_REMOVE: window %s not in stack",
-                       get_window_desc (tracker, op->remove.window));
+            meta_topic (META_DEBUG_STACK,
+                        "STACK_OP_REMOVE: window %s not in stack",
+                        get_window_desc (tracker, op->remove.window));
             return FALSE;
           }
 
@@ -416,8 +418,9 @@ meta_stack_op_apply (MetaStackTracker *tracker,
         old_pos = find_window (stack, op->raise_above.window);
         if (old_pos < 0)
           {
-            g_warning ("STACK_OP_RAISE_ABOVE: window %s not in stack",
-                       get_window_desc (tracker, op->raise_above.window));
+            meta_topic (META_DEBUG_STACK,
+                        "STACK_OP_RAISE_ABOVE: window %s not in stack",
+                        get_window_desc (tracker, op->raise_above.window));
             return FALSE;
           }
 
@@ -426,8 +429,9 @@ meta_stack_op_apply (MetaStackTracker *tracker,
             above_pos = find_window (stack, op->raise_above.sibling);
             if (above_pos < 0)
               {
-                g_warning ("STACK_OP_RAISE_ABOVE: sibling window %s not in stack",
-                           get_window_desc (tracker, op->raise_above.sibling));
+                meta_topic (META_DEBUG_STACK,
+                            "STACK_OP_RAISE_ABOVE: sibling window %s not in stack",
+                            get_window_desc (tracker, op->raise_above.sibling));
                 return FALSE;
               }
           }
@@ -447,8 +451,9 @@ meta_stack_op_apply (MetaStackTracker *tracker,
         old_pos = find_window (stack, op->raise_above.window);
         if (old_pos < 0)
           {
-            g_warning ("STACK_OP_LOWER_BELOW: window %s not in stack",
-                       get_window_desc (tracker, op->lower_below.window));
+            meta_topic (META_DEBUG_STACK,
+                        "STACK_OP_LOWER_BELOW: window %s not in stack",
+                        get_window_desc (tracker, op->lower_below.window));
             return FALSE;
           }
 
@@ -459,8 +464,9 @@ meta_stack_op_apply (MetaStackTracker *tracker,
             below_pos = find_window (stack, op->lower_below.sibling);
             if (below_pos < 0)
               {
-                g_warning ("STACK_OP_LOWER_BELOW: sibling window %s not in stack",
-                           get_window_desc (tracker, op->lower_below.sibling));
+                meta_topic (META_DEBUG_STACK,
+                            "STACK_OP_LOWER_BELOW: sibling window %s not in stack",
+                            get_window_desc (tracker, op->lower_below.sibling));
                 return FALSE;
               }