[geary/mjog/misc-criticals: 3/9] Geary.Util.Logging: Avoid logging any destroyed loggable objects

[Michael Gratton <mjog src gnome org>]

commit 16a25870f42928ab153016bb6be3bf82021a84ef
Author: Michael Gratton <mike vee net>
Date:   Thu Jun 25 21:00:44 2020 +1000

    Geary.Util.Logging: Avoid logging any destroyed loggable objects
    
    Extends the fix for commit 8c43288b to all logging parents as well. Use
    a weak ref so we don't try to ref loggable objects that are already
    destroyed.
    
    Fixes #875

 src/engine/util/util-logging.vala | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)
---
diff --git a/src/engine/util/util-logging.vala b/src/engine/util/util-logging.vala
index c4c517cde..acfdc97d3 100644
--- a/src/engine/util/util-logging.vala
+++ b/src/engine/util/util-logging.vala
@@ -538,12 +538,14 @@ public interface Geary.Logging.Source : GLib.Object {
                                        va_list args) {
         Context context = Context(this.logging_domain, levels, fmt, args);
 
-        // Don't attempt to this object if it is in the middle of
-        // being destructed, which can happen when logging from
-        // the destructor.
-        Source? decorated = (this.ref_count > 0) ? this : this.logging_parent;
+        weak Source? decorated = this;
         while (decorated != null) {
-            context.append_source(decorated);
+            // Check ref counts of logged objects and don't log them
+            // if they are or have been being destroyed, which can
+            // happen when e.g. logging from the destructor.
+            if (decorated.ref_count > 0) {
+                context.append_source(decorated);
+            }
             decorated = decorated.logging_parent;
         }