Fix IDEA project open hang

CHANGELOG.md

@@ -7,6 +7,8 @@
 ### Removed
 
 ### Fixed
+- Silent failure when opening Flutter projects without `.idea` directory in IntelliJ IDEA, by removing `FlutterProjectOpenProcessor` and
+  migrating configuration logic to `FlutterInitializer`. (#8903)
 
 ## 91.0.0
 

resources/META-INF/plugin.xml

@@ -335,8 +335,6 @@
     <!-- See https://github.com/flutter/flutter-intellij/issues/8029 -->
     <projectService serviceImplementation="io.flutter.view.InspectorView" overrides="false"/>
 
-    <projectOpenProcessor id="flutter" implementation="io.flutter.project.FlutterProjectOpenProcessor" order="first"/>
-
     <editorNotificationProvider implementation="io.flutter.editor.FlutterPubspecNotificationProvider"/>
     <editorNotificationProvider implementation="io.flutter.inspections.SdkConfigurationNotificationProvider"/>
     <editorNotificationProvider implementation="io.flutter.editor.NativeEditorNotificationProvider"/>

src/io/flutter/FlutterInitializer.java

@@ -67,8 +67,6 @@
  * Runs actions after the project has started up and the index is up to date.
  *
  * @see ProjectOpenActivity for actions that run earlier.
- * @see io.flutter.project.FlutterProjectOpenProcessor for additional actions that
- * may run when a project is being imported.
  */
 public class FlutterInitializer extends FlutterProjectActivity {
   private boolean toolWindowsInitialized = false;
@@ -115,8 +113,19 @@ public void executeProjectStartup(@NotNull Project project) {
       }
 
       log().info("Flutter module has been found for project: " + project.getName());
-      // Ensure SDKs are configured; needed for clean module import.
-      FlutterModuleUtils.enableDartSDK(module);
+
+      // Ensure Flutter project configuration is applied for projects that may have been
+      // opened without a .idea directory. Previously this was handled by FlutterProjectOpenProcessor,
+      // but that processor silently failed when no delegate processor could open the project.
+      // Instead, we let the platform open the project normally and apply our configuration here.
+      // See https://github.com/flutter/flutter-intellij/issues/8661 (Android Studio equivalent)
+      if (!FlutterModuleUtils.isFlutterModule(module)) {
+        log().info("Fixing Flutter module configuration for " + module.getName());
+        FlutterModuleUtils.setFlutterModuleWithoutReload(module, project);
+      } else {
+        // Ensure SDKs are configured; needed for clean module import.
+        FlutterModuleUtils.enableDartSDK(module);
+      }
 
       for (PubRoot root : PubRoots.forModule(module)) {
         // Set Android SDK.

src/io/flutter/utils/FlutterModuleUtils.java

@@ -373,15 +373,14 @@ public static void setFlutterModuleType(@NotNull Module module) {
     module.setModuleType(getModuleTypeIDForFlutter());
   }
 
-  public static void setFlutterModuleAndReload(@NotNull Module module, @NotNull Project project) {
+  public static void setFlutterModuleWithoutReload(@NotNull Module module, @NotNull Project project) {
     if (project.isDisposed()) return;
     ApplicationManager.getApplication().invokeLater(() -> {
       ApplicationManager.getApplication().runWriteAction(() -> setFlutterModuleType(module));
       enableDartSDK(module);
       project.save();
 
       EditorNotifications.getInstance(project).updateAllNotifications();
-      ProjectManager.getInstance().reloadProject(project);
     });
   }