fix(ui): show effective runtime model in dropdown after fallback/drift

mmyzwl · claude · mmyzwl · commit fb453e7da1cc · 2026-06-15T23:57:19.000+08:00
When the runtime silently falls back to the default model, the chat model dropdown showed the stale user-selected model instead of the effective model. The cached override always won, even when the session's actual model had changed. Fix: compare the cached override with the session's effective server model. When they differ (fallback/default drift), show the effective model so the dropdown reflects reality. Closes #93346 Co-Authored-By: Claude <noreply@anthropic.com>
diff --git a/ui/src/ui/chat-model-select-state.ts b/ui/src/ui/chat-model-select-state.ts
@@ -34,11 +34,24 @@ function resolveActiveSessionRow(state: ChatModelSelectStateInput) {
 
 export function resolveChatModelOverrideValue(state: ChatModelSelectStateInput): string {
   const catalog = state.chatModelCatalog ?? [];
-
-  // Prefer the local cache — it reflects in-flight patches before sessionsResult refreshes.
   const cached = state.chatModelOverrides[state.sessionKey];
+
+  // When a local override is cached, also resolve the effective server model
+  // so the dropdown reflects the actual runtime model after fallback/default drift.
   if (cached) {
-    return normalizeChatModelOverrideValue(cached, catalog);
+    const cachedValue = normalizeChatModelOverrideValue(cached, catalog);
+    const activeRow = resolveActiveSessionRow(state);
+    const serverValue = resolvePreferredServerChatModelValue(
+      activeRow?.model,
+      activeRow?.modelProvider,
+      catalog,
+    );
+    // If the effective session model differs from the cached override, the
+    // runtime has fallen back or drifted — show the effective model instead.
+    if (serverValue && cachedValue !== serverValue) {
+      return serverValue;
+    }
+    return cachedValue;
   }
   if (cached === null) {
     return "";
