fix: prevent system messages from being ignored in multi-channel search (#3875)

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## Unversioned
 
-- Major: Added multi-channel searching to search dialog via keyboard shortcut. (Ctrl+Shift+F by default) (#3694)
+- Major: Added multi-channel searching to search dialog via keyboard shortcut. (Ctrl+Shift+F by default) (#3694, #3875)
 - Minor: Added option to display tabs on the right and bottom. (#3847)
 - Minor: Added `is:first-msg` search option. (#3700)
 - Minor: Added quotation marks in the permitted/blocked Automod messages for clarity. (#3654)

src/widgets/helper/SearchPopup.cpp

@@ -188,7 +188,8 @@ LimitedQueueSnapshot<MessagePtr> SearchPopup::buildSnapshot()
     auto uniqueIterator =
         std::unique(combinedSnapshot.begin(), combinedSnapshot.end(),
                     [](MessagePtr &a, MessagePtr &b) {
-                        return a->id == b->id;
+                        // nullptr check prevents system messages from being dropped
+                        return (a->id != nullptr) && a->id == b->id;
                     });
 
     combinedSnapshot.erase(uniqueIterator, combinedSnapshot.end());