fix: resolve orchestrator subtask cancellation during API streaming error (#4896)

- Add setTimeout to prevent race condition when aborting streams
- Enhance error logging with parent task ID for better debugging
- Improve error handling to ensure parent task resumption
- Make resumePausedTask more resilient to aborted states

Fixes #4896

Author: hannesrudolph

src/core/task/Task.ts

@@ -758,6 +758,14 @@ export class Task extends EventEmitter<ClineEvents> {
 		// this is the result of what it has done  add the message to the chat
 		// history and to the webview ui.
 		try {
+			// Check if the task is aborted or abandoned before trying to add messages
+			if (this.abort || this.abandoned) {
+				this.providerRef
+					.deref()
+					?.log(`[subtasks] Parent task ${this.taskId} is aborted/abandoned, skipping resume message`)
+				return
+			}
+
 			await this.say("subtask_result", lastMessage)
 
 			await this.addToApiConversationHistory({
@@ -769,7 +777,8 @@ export class Task extends EventEmitter<ClineEvents> {
 				.deref()
 				?.log(`Error failed to add reply from subtask into conversation of parent task, error: ${error}`)
 
-			throw error
+			// Don't throw the error - we still want the parent task to be unpaused
+			// even if we couldn't add the message
 		}
 	}
 

src/core/webview/webviewMessageHandler.ts

@@ -204,7 +204,21 @@ export const webviewMessageHandler = async (
 			// Check if the current task actually has a parent task
 			const currentTask = provider.getCurrentCline()
 			if (currentTask && currentTask.parentTask) {
-				await provider.finishSubTask(t("common:tasks.canceled"))
+				// For subtasks, we need to ensure the parent task is resumed even if the subtask is in an error state
+				try {
+					// First abort the current subtask if it's still running
+					if (currentTask.isStreaming || !currentTask.didFinishAbortingStream) {
+						currentTask.abortTask()
+						// Small delay to ensure abort signal is processed before cleanup
+						// This prevents race conditions where the stream might still be processing
+						await new Promise((resolve) => setTimeout(resolve, 100))
+					}
+					await provider.finishSubTask(t("common:tasks.canceled"))
+				} catch (error) {
+					// If there's an error, still try to resume the parent task
+					provider.log(`Error during subtask cancellation: ${error}`)
+					await provider.finishSubTask(t("common:tasks.canceled"))
+				}
 			} else {
 				// Regular task - just clear it
 				await provider.clearTask()