IJPL-171566 Invalidate allParents on plugin unload as much late as possible to avoid leaked unloaded class loaders via allParents property

GitOrigin-RevId: 11dda096063fbcad479ada2517a8b84f1fa9134c

platform/platform-impl/src/com/intellij/ide/plugins/DynamicPlugins.kt

@@ -542,8 +542,6 @@ object DynamicPlugins {
           unloadDependencyDescriptors(pluginDescriptor, pluginSet, classLoaders)
           unloadModuleDescriptorNotRecursively(pluginDescriptor)
 
-          clearPluginClassLoaderParentListCache(pluginSet)
-
           app.extensionArea.clearUserCache()
           for (project in ProjectUtil.getOpenProjects()) {
             (project.extensionArea as ExtensionsAreaImpl).clearUserCache()
@@ -576,12 +574,17 @@ object DynamicPlugins {
           @Suppress("TestOnlyProblems")
           (ProjectManager.getInstanceIfCreated() as? ProjectManagerImpl)?.disposeDefaultProjectAndCleanupComponentsForDynamicPluginTests()
 
+          // clear parents as much late as possible because allParents are a lazy list and calculated on demand
+          // it may happen that too early invalidation may lead to unloaded loaders appear in allParents again (IJPL-171566)
+          clearPluginClassLoaderParentListCache(pluginSet)
           val newPluginSet = pluginSet.withoutModule(
             module = pluginDescriptor,
             disable = options.disable,
           ).createPluginSetWithEnabledModulesMap()
 
           PluginManagerCore.setPluginSet(newPluginSet)
+          // clear parents cache for newPluginSet just for a case
+          clearPluginClassLoaderParentListCache(newPluginSet)
         }
         finally {
           try {
@@ -1411,8 +1414,9 @@ private fun setClassLoaderState(pluginDescriptor: IdeaPluginDescriptorImpl, stat
 }
 
 private fun clearPluginClassLoaderParentListCache(pluginSet: PluginSet) {
-  // yes, clear not only enabled plugins, but all, just to be sure; it's a cheap operation
-  for (descriptor in pluginSet.allPlugins) {
+  // yes, clear not only enabled plugins, but (all + enabledModules) because enabledModules is a superset of enabledPlugins
+  // it's a cheap operation and even if some modules may repeat due to concatenation, it should be not a problem (making a set is probably even slower)
+  for (descriptor in pluginSet.allPlugins + pluginSet.getEnabledModules()) {
     (descriptor.pluginClassLoader as? PluginClassLoader)?.clearParentListCache()
   }
 }