fix: preserve message history after condense and rewind operations

- Fixed bug where rewinding after condensing would lose intervening message history
- Updated handleDeleteMessageConfirm to check for condense_context in preserved messages
- Prevents incorrect API history truncation when condensed context exists
- Added comprehensive test coverage for condense-rewind scenarios

Fixes #8295

Author: roomote

.tmp/review/Roo-Code

@@ -0,0 +1 @@
+Subproject commit 8dbd8c4b1b72fb48be3990a8e78285a787a1828c

src/core/webview/__tests__/webviewMessageHandler.condense-rewind.spec.ts

@@ -0,0 +1,288 @@
+import { describe, it, expect, vi, beforeEach } from "vitest"
+import { webviewMessageHandler } from "../webviewMessageHandler"
+import { ClineProvider } from "../ClineProvider"
+import { Task } from "../../task/Task"
+import { ClineMessage } from "@roo-code/types"
+
+// Mock vscode module
+vi.mock("vscode", () => ({
+	window: {
+		showErrorMessage: vi.fn(),
+		showWarningMessage: vi.fn(),
+	},
+	workspace: {
+		workspaceFolders: [],
+		getConfiguration: vi.fn(() => ({
+			get: vi.fn(),
+		})),
+	},
+}))
+
+describe("webviewMessageHandler - Condense and Rewind", () => {
+	let mockProvider: any
+	let mockTask: any
+
+	beforeEach(() => {
+		// Create mock task
+		mockTask = {
+			taskId: "test-task-id",
+			clineMessages: [] as ClineMessage[],
+			apiConversationHistory: [],
+			overwriteClineMessages: vi.fn(),
+			overwriteApiConversationHistory: vi.fn(),
+			saveClineMessages: vi.fn(),
+			skipPrevResponseIdOnce: false,
+		}
+
+		// Create mock provider
+		mockProvider = {
+			getCurrentTask: vi.fn().mockReturnValue(mockTask),
+			postMessageToWebview: vi.fn(),
+			postStateToWebview: vi.fn(),
+			contextProxy: {
+				globalStorageUri: { fsPath: "/test/storage" },
+			},
+			log: vi.fn(),
+		}
+	})
+
+	describe("Bug #8295: Rewind after manual condense keeps only initial + new message", () => {
+		it("should preserve messages up to rewind point after condense", async () => {
+			// Setup: Create messages 1-11 with a condense_context message after message 10
+			const messages: ClineMessage[] = []
+
+			// Add initial message
+			messages.push({
+				ts: 1000,
+				type: "say",
+				say: "text",
+				text: "Initial message",
+			})
+
+			// Add messages 1-10 (jokes)
+			for (let i = 1; i <= 10; i++) {
+				messages.push({
+					ts: 1000 + i * 100,
+					type: "say",
+					say: "user_feedback",
+					text: `tell me a joke ${i}`,
+				})
+				messages.push({
+					ts: 1000 + i * 100 + 50,
+					type: "say",
+					say: "text",
+					text: `Here's joke ${i}...`,
+				})
+			}
+
+			// Add condense_context message after message 10
+			messages.push({
+				ts: 3000,
+				type: "say",
+				say: "condense_context",
+				contextCondense: {
+					summary: "Conversation condensed",
+					cost: 0.001,
+					prevContextTokens: 5000,
+					newContextTokens: 1000,
+				},
+			})
+
+			// Add message 11
+			messages.push({
+				ts: 3100,
+				type: "say",
+				say: "user_feedback",
+				text: "tell me a joke 11",
+			})
+			messages.push({
+				ts: 3150,
+				type: "say",
+				say: "text",
+				text: "Here's joke 11...",
+			})
+
+			mockTask.clineMessages = [...messages]
+
+			// Find the timestamp of message 8 (the user feedback for joke 8)
+			const message8Index = messages.findIndex(
+				(m) => m.type === "say" && m.say === "user_feedback" && m.text === "tell me a joke 8",
+			)
+			const message8Ts = messages[message8Index].ts
+
+			// Act: Delete message 8 and all subsequent messages
+			await webviewMessageHandler(mockProvider, {
+				type: "deleteMessageConfirm",
+				messageTs: message8Ts,
+			})
+
+			// Assert: Check that messages up to joke 7 are preserved
+			expect(mockTask.overwriteClineMessages).toHaveBeenCalled()
+			const preservedMessages = mockTask.overwriteClineMessages.mock.calls[0][0]
+
+			// Should have initial message + jokes 1-7 (each joke is 2 messages: user + assistant)
+			// That's 1 + (7 * 2) = 15 messages
+			expect(preservedMessages.length).toBe(15)
+
+			// Verify the last preserved message is the assistant response to joke 7
+			const lastPreserved = preservedMessages[preservedMessages.length - 1]
+			expect(lastPreserved.text).toBe("Here's joke 7...")
+
+			// Verify skipPrevResponseIdOnce is NOT set (since last message is not condense_context)
+			expect(mockTask.skipPrevResponseIdOnce).toBe(false)
+		})
+
+		it("should set skipPrevResponseIdOnce when deletion leaves condense_context as last message", async () => {
+			// Setup: Create a simpler scenario with condense_context as the last message after deletion
+			const messages: ClineMessage[] = [
+				{
+					ts: 1000,
+					type: "say",
+					say: "text",
+					text: "Initial message",
+				},
+				{
+					ts: 1100,
+					type: "say",
+					say: "user_feedback",
+					text: "First request",
+				},
+				{
+					ts: 1200,
+					type: "say",
+					say: "text",
+					text: "First response",
+				},
+				{
+					ts: 1300,
+					type: "say",
+					say: "condense_context",
+					contextCondense: {
+						summary: "Condensed",
+						cost: 0.001,
+						prevContextTokens: 1000,
+						newContextTokens: 200,
+					},
+				},
+				{
+					ts: 1400,
+					type: "say",
+					say: "user_feedback",
+					text: "Second request",
+				},
+				{
+					ts: 1500,
+					type: "say",
+					say: "text",
+					text: "Second response",
+				},
+			]
+
+			mockTask.clineMessages = [...messages]
+
+			// Act: Delete the message after condense_context
+			await webviewMessageHandler(mockProvider, {
+				type: "deleteMessageConfirm",
+				messageTs: 1400, // Delete "Second request" and everything after
+			})
+
+			// Assert: Verify the preserved messages
+			expect(mockTask.overwriteClineMessages).toHaveBeenCalled()
+			const preservedMessages = mockTask.overwriteClineMessages.mock.calls[0][0]
+
+			// Should preserve up to and including the condense_context message
+			expect(preservedMessages.length).toBe(4)
+			expect(preservedMessages[preservedMessages.length - 1].say).toBe("condense_context")
+		})
+
+		it("should handle rewind to specific message correctly after condense", async () => {
+			// This test specifically reproduces the bug scenario from issue #8295
+			// Setup: Messages 1-11 with condense after 10, then rewind to 8
+			const messages: ClineMessage[] = []
+
+			// Initial message
+			messages.push({
+				ts: 1000,
+				type: "say",
+				say: "text",
+				text: "Initial task",
+			})
+
+			// Messages 1-10
+			for (let i = 1; i <= 10; i++) {
+				messages.push({
+					ts: 1000 + i * 200,
+					type: "say",
+					say: "user_feedback",
+					text: `tell me a joke ${i}`,
+				})
+				messages.push({
+					ts: 1000 + i * 200 + 100,
+					type: "say",
+					say: "text",
+					text: `Joke ${i}: Why did the ${i} cross the road?`,
+				})
+			}
+
+			// Condense after message 10
+			messages.push({
+				ts: 4000,
+				type: "say",
+				say: "condense_context",
+				contextCondense: {
+					summary: "User asked for 10 jokes, all delivered successfully",
+					cost: 0.002,
+					prevContextTokens: 3000,
+					newContextTokens: 500,
+				},
+			})
+
+			// Message 11
+			messages.push({
+				ts: 4100,
+				type: "say",
+				say: "user_feedback",
+				text: "tell me a joke 11",
+			})
+			messages.push({
+				ts: 4200,
+				type: "say",
+				say: "text",
+				text: "Joke 11: Why did the 11 cross the road?",
+			})
+
+			mockTask.clineMessages = [...messages]
+
+			// Find message 8's timestamp
+			const joke8UserIndex = messages.findIndex(
+				(m) => m.type === "say" && m.say === "user_feedback" && m.text === "tell me a joke 8",
+			)
+			const joke8UserTs = messages[joke8UserIndex].ts
+
+			// Act: Rewind to message 8 (delete this and after)
+			await webviewMessageHandler(mockProvider, {
+				type: "deleteMessageConfirm",
+				messageTs: joke8UserTs,
+			})
+
+			// Assert: Messages 1-7 should be preserved
+			expect(mockTask.overwriteClineMessages).toHaveBeenCalled()
+			const preservedMessages = mockTask.overwriteClineMessages.mock.calls[0][0]
+
+			// Expected: initial + 7 jokes (each joke = 2 messages) = 1 + 14 = 15 messages
+			expect(preservedMessages.length).toBe(15)
+
+			// Verify we have jokes 1-7 but not 8-11
+			const joke7Present = preservedMessages.some((m: ClineMessage) => m.text?.includes("Joke 7:"))
+			const joke8Present = preservedMessages.some((m: ClineMessage) => m.text?.includes("Joke 8:"))
+			const condensePresent = preservedMessages.some((m: ClineMessage) => m.say === "condense_context")
+
+			expect(joke7Present).toBe(true)
+			expect(joke8Present).toBe(false)
+			expect(condensePresent).toBe(false)
+
+			// The last message should be the response to joke 7
+			expect(preservedMessages[preservedMessages.length - 1].text).toContain("Joke 7:")
+		})
+	})
+})

src/core/webview/webviewMessageHandler.ts

@@ -156,10 +156,20 @@ export const webviewMessageHandler = async (
 		}
 
 		const { messageIndex, apiConversationHistoryIndex } = findMessageIndices(messageTs, currentCline)
-		// Determine API truncation index with timestamp fallback if exact match not found
+
+		// Check if there's a condense_context message in the preserved messages
+		const hasCondenseInPreservedMessages =
+			messageIndex > 0 &&
+			currentCline.clineMessages.slice(0, messageIndex).some((msg) => msg.say === "condense_context")
+
+		// Determine API truncation index with special handling for post-condense scenarios
 		let apiIndexToUse = apiConversationHistoryIndex
 		const tsThreshold = currentCline.clineMessages[messageIndex]?.ts
-		if (apiIndexToUse === -1 && typeof tsThreshold === "number") {
+
+		// After condensing, the API conversation history is already condensed
+		// We should not use findFirstApiIndexAtOrAfter when there's a condense in preserved messages
+		// as it would incorrectly truncate the condensed context
+		if (apiIndexToUse === -1 && typeof tsThreshold === "number" && !hasCondenseInPreservedMessages) {
 			apiIndexToUse = findFirstApiIndexAtOrAfter(tsThreshold, currentCline)
 		}
 
@@ -206,6 +216,7 @@ export const webviewMessageHandler = async (
 				}
 
 				// Delete this message and all subsequent messages
+				// The overwriteClineMessages method in Task will handle setting skipPrevResponseIdOnce if needed
 				await removeMessagesThisAndSubsequent(currentCline, messageIndex, apiIndexToUse)
 
 				// Restore checkpoint associations for preserved messages