fix(webview): omit originalContent from webview messages and fetch on demand

packages/types/src/vscode-extension-host.ts

@@ -106,11 +106,14 @@ export interface ExtensionMessage {
 		| "skills"
 		| "rules"
 		| "fileContent"
+		| "originalContent"
 		| "rooHistoryImportProgress"
 		| "themeFixtureProbeRequest"
 	text?: string
 	/** For fileContent: { path, content, error? } */
 	fileContent?: { path: string; content: string | null; error?: string }
+	/** For originalContent: the pre-edit file content of the requested tool message (null when unavailable) */
+	originalContentInfo?: { ts: number; messageId?: string; taskId?: string; content: string | null }
 	payload?: any // eslint-disable-line @typescript-eslint/no-explicit-any
 	checkpointWarning?: {
 		type: "WAIT_TIMEOUT" | "INIT_TIMEOUT"
@@ -499,6 +502,7 @@ export interface WebviewMessage {
 		| "saveImage"
 		| "openFile"
 		| "readFileContent"
+		| "readOriginalContent"
 		| "openMention"
 		| "cancelTask"
 		| "cancelAutoApproval"
@@ -697,6 +701,7 @@ export interface WebviewMessage {
 	ids?: string[]
 	terminalOperation?: "continue" | "abort"
 	messageTs?: number
+	messageId?: string
 	restoreCheckpoint?: boolean
 	historyPreviewCollapsed?: boolean
 	filters?: { type?: string; search?: string; tags?: string[] }
@@ -859,6 +864,8 @@ export interface ClineSayTool {
 	content?: string
 	// Original file content before first edit (for merged diff display in FileChangesPanel)
 	originalContent?: string
+	// Length of the originalContent the extension left out of the webview state (request it with readOriginalContent)
+	originalContentLength?: number
 	// Unified diff statistics computed by the extension
 	diffStats?: { added: number; removed: number }
 	regex?: string

src/core/webview/ClineProvider.ts

@@ -131,6 +131,7 @@ import {
 import { readTaskMessages } from "../task-persistence/taskMessages"
 import { getNonce } from "./getNonce"
 import { getUri } from "./getUri"
+import { omitOriginalContentFromExtensionMessage } from "./stripOriginalContent"
 import { REQUESTY_BASE_URL } from "../../shared/utils/requesty"
 import { validateAndFixToolResultIds } from "../task/validateToolResultIds"
 import { PendingEditOperationStore, type PendingEditOperationInput } from "./PendingEditOperationStore"
@@ -1466,7 +1467,7 @@ export class ClineProvider
 		}
 
 		try {
-			await this.view?.webview.postMessage(message)
+			await this.view?.webview.postMessage(omitOriginalContentFromExtensionMessage(message))
 		} catch {
 			// View disposed, drop message silently
 		}

src/core/webview/__tests__/ClineProvider.spec.ts

@@ -841,6 +841,60 @@ describe("ClineProvider", () => {
 		await expect(provider.postMessageToWebview(message)).resolves.toBeUndefined()
 	})
 
+	test("postMessageToWebview leaves originalContent of file-edit tool messages out of the state it posts", async () => {
+		await provider.resolveWebviewView(mockWebviewView)
+
+		const originalFile = "line of the original file\n".repeat(500)
+		const toolText = JSON.stringify({
+			tool: "appliedDiff",
+			path: "a.ts",
+			diff: "@@ d",
+			originalContent: originalFile,
+		})
+		// Only the field under test is populated; the rest of ExtensionState is irrelevant here.
+		const message = {
+			type: "state",
+			state: { clineMessages: [{ ts: 1, type: "ask", ask: "tool", text: toolText }] },
+		} as unknown as ExtensionMessage
+
+		await provider.postMessageToWebview(message)
+
+		const posted = mockPostMessage.mock.calls.at(-1)![0] as ExtensionMessage
+		const postedText = posted.state!.clineMessages![0]!.text!
+
+		expect(JSON.parse(postedText)).toEqual({
+			tool: "appliedDiff",
+			path: "a.ts",
+			diff: "@@ d",
+			originalContentLength: originalFile.length,
+		})
+		// the extension's own message (and so the persisted task) keeps the full content
+		expect(message.state!.clineMessages![0]!.text).toBe(toolText)
+	})
+
+	test("postMessageToWebview leaves originalContent out of messageUpdated", async () => {
+		await provider.resolveWebviewView(mockWebviewView)
+
+		const toolText = JSON.stringify({
+			tool: "appliedDiff",
+			path: "a.ts",
+			originalContent: "original file\n".repeat(100),
+		})
+
+		await provider.postMessageToWebview({
+			type: "messageUpdated",
+			clineMessage: { ts: 2, type: "ask", ask: "tool", text: toolText },
+		})
+
+		const posted = mockPostMessage.mock.calls.at(-1)![0] as ExtensionMessage
+
+		expect(JSON.parse(posted.clineMessage!.text!)).toEqual({
+			tool: "appliedDiff",
+			path: "a.ts",
+			originalContentLength: "original file\n".length * 100,
+		})
+	})
+
 	describe("theme fixture probes", () => {
 		const fixture = {
 			themeId: "Default Dark Modern",