Merge pull request #6391 from basecamp/bar-startup-churn

Load each bar widget's component once

shell/shell.qml

@@ -700,6 +700,12 @@ ShellRoot {
         source: "plugin"
       }
 
+      // A load already in flight for this URL registers itself when it
+      // finishes. Starting a second one produces a second Component for the
+      // same widget, and swapping a slot's component rebuilds its item —
+      // briefly running two of the widget, each registering its IPC handler.
+      if (existing && existing.url === url && !existing.component) continue
+
       // If the component URL is unchanged, just refresh the metadata in
       // place. We can't skip this even when the URL matches: manifests can
       // change schema, defaults, or sourceDir between rescans, and the
@@ -769,17 +775,29 @@ ShellRoot {
     }
   }
 
+  function setPluginWidgetComponent(registryKey, entry) {
+    var next = ({})
+    for (var k in pluginWidgetComponents) if (k !== registryKey) next[k] = pluginWidgetComponents[k]
+    if (entry) next[registryKey] = entry
+    pluginWidgetComponents = next
+  }
+
   function loadPluginWidget(registryKey, url, meta) {
+    // Claim the key before the component exists. Qt.createComponent is
+    // asynchronous and syncPluginWidgets runs several times while the shell
+    // starts, so without a marker the later passes cannot tell a load in
+    // flight from one that never happened.
+    setPluginWidgetComponent(registryKey, { url: url, component: null })
+
     var comp = Qt.createComponent(url, Component.Asynchronous)
     function finalize() {
       if (comp.status === Component.Ready) {
         shell.barWidgetRegistry.register(registryKey, comp, meta)
-        var next = ({})
-        for (var k in pluginWidgetComponents) next[k] = pluginWidgetComponents[k]
-        next[registryKey] = { url: url, component: comp }
-        pluginWidgetComponents = next
+        shell.setPluginWidgetComponent(registryKey, { url: url, component: comp })
       } else if (comp.status === Component.Error) {
         console.warn("Plugin widget " + registryKey + " failed: " + comp.errorString())
+        // Drop the claim so a later rescan can retry.
+        shell.setPluginWidgetComponent(registryKey, null)
         shell.pluginRegistry.pluginLoadFailed(registryKey, comp.errorString())
       }
     }

test/shell.d/runtime-smoke-test.sh

@@ -230,6 +230,24 @@ for panel_id in omarchy.audio omarchy.bluetooth omarchy.monitor omarchy.network
 done
 pass "direct panel IPC opens and closes default panels"
 
+# Each widget registers its IPC handler once per bar, and the bar is
+# instantiated once per screen, so Quickshell reports one collision per screen
+# past the first. Anything beyond that is two instances on the same screen —
+# the shape duplicate component loads produced, where a sync pass that ran
+# while a widget's asynchronous load was still in flight started a second one.
+# Checked before the reload below, which rebuilds widgets by design.
+screens=$(hyprctl -j monitors 2>/dev/null | jq 'length' 2>/dev/null || true)
+[[ $screens =~ ^[0-9]+$ ]] && (( screens > 0 )) || screens=1
+# No matches is the good case, and pipefail would otherwise abort the run.
+worst=$(grep -oE "another handler is registered for target [a-z.-]+" "$log" |
+  sort | uniq -c | sort -rn | head -1 | awk '{print $1}' || true)
+worst=${worst:-0}
+if (( worst > screens - 1 )); then
+  grep "another handler is registered for target" "$log" | sed 's/^/  /' | head -20 >&2
+  fail_with_log "each widget registers its IPC handler once per screen (saw $worst for $screens screen(s))"
+fi
+pass "each widget registers its IPC handler once per screen"
+
 HOME="$test_home" OMARCHY_PATH="$test_root" PATH="$ROOT/bin:$PATH" "$ROOT/bin/omarchy-bar-plugin" remove omarchy.audio
 
 for _ in {1..80}; do
@@ -257,3 +275,4 @@ jq -e 'all(.[]; .id != "omarchy.audio")' <<<"$geometry" >/dev/null || {
 }
 
 pass "bar remove reloads shell config and updates bar layout"
+