fix(coding-agent): expand paste markers in Ctrl+Q follow-ups

InputController.handleFollowUp read raw editor text via getText(),
bypassing the paste-store expansion the Enter path applies through
Editor.getExpandedText(). A large paste collapsed into a [Paste #N, +X
lines] marker was therefore sent verbatim to the model when queued with
Ctrl+Q / Ctrl+Enter, silently dropping the pasted content.

Switch the follow-up path to getExpandedText() so queued submissions
match the Enter path. Image markers are untouched; pendingImages
forwarding is unchanged.

Updated existing input-controller stubs (skill-queue, followup-image,
keybindings) to implement getExpandedText, matching the production
CustomEditor surface.

Fixes #3737

packages/coding-agent/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed Ctrl+Q / Ctrl+Enter follow-up submissions sending the literal `[Paste #N]` marker instead of the expanded paste body ([#3737](https://github.com/can1357/oh-my-pi/issues/3737)).
+
 ## [16.2.3] - 2026-06-28
 
 ### Added

packages/coding-agent/src/modes/controllers/input-controller.ts

@@ -1145,7 +1145,7 @@ export class InputController {
 
 	/** Send editor text as a follow-up message (queued behind current stream). */
 	async handleFollowUp(): Promise<void> {
-		let text = this.ctx.editor.getText().trim();
+		let text = this.ctx.editor.getExpandedText().trim();
 		const images = this.ctx.editor.pendingImages.length > 0 ? [...this.ctx.editor.pendingImages] : undefined;
 		const imageLinks =
 			images && this.ctx.editor.pendingImageLinks.length > 0 ? [...this.ctx.editor.pendingImageLinks] : undefined;

packages/coding-agent/test/input-controller-followup-image.test.ts

@@ -13,6 +13,7 @@ import type { InteractiveModeContext } from "@oh-my-pi/pi-coding-agent/modes/typ
 interface StubEditor {
 	setText: (text: string) => void;
 	getText: () => string;
+	getExpandedText: () => string;
 	addToHistory: (text: string) => void;
 	imageLinks?: unknown;
 	pendingImages: ImageContent[];
@@ -37,6 +38,9 @@ function createContext(opts: {
 		getText() {
 			return editorText;
 		},
+		getExpandedText() {
+			return editorText;
+		},
 		addToHistory: vi.fn(),
 		pendingImages: opts.pendingImages,
 		pendingImageLinks: opts.pendingImageLinks ? [...opts.pendingImageLinks] : opts.pendingImages.map(() => undefined),

packages/coding-agent/test/input-controller-followup-paste-expansion.test.ts

@@ -0,0 +1,116 @@
+/**
+ * Regression: queuing a follow-up message (Ctrl+Q / Ctrl+Enter → `app.message.followUp`)
+ * with a collapsed `[Paste #N, +X lines]` marker must expand the marker to its stored text
+ * before dispatch, identical to the Enter path. Previously `handleFollowUp` read raw
+ * `getText()` so the model received the literal marker string and the paste was silently
+ * dropped (issue #3737).
+ */
+import { afterEach, describe, expect, it, vi } from "bun:test";
+import { InputController } from "@oh-my-pi/pi-coding-agent/modes/controllers/input-controller";
+import type { InteractiveModeContext } from "@oh-my-pi/pi-coding-agent/modes/types";
+
+interface PromptOptionsLike {
+	streamingBehavior?: "steer" | "followUp";
+}
+
+describe("InputController.handleFollowUp paste-marker expansion", () => {
+	afterEach(() => {
+		vi.restoreAllMocks();
+	});
+
+	it("expands [Paste #N] markers to their stored text before dispatch while streaming", async () => {
+		const expanded = "line1\nline2\nline3\nline4\nline5";
+		let editorText = "[Paste #1, +5 lines]";
+		const prompt = vi.fn(async (_text: string, _options?: PromptOptionsLike) => {});
+		const ctx = {
+			editor: {
+				setText(text: string) {
+					editorText = text;
+				},
+				getText: () => editorText,
+				getExpandedText: () =>
+					editorText.replace(/\[Paste #1(?:, (?:\+\d+ lines|\d+ chars))?\]/g, expanded),
+				addToHistory: vi.fn(),
+				pendingImages: [],
+				pendingImageLinks: [],
+				clearDraft(text?: string) {
+					if (text !== undefined) this.addToHistory(text);
+					this.setText("");
+				},
+			},
+			ui: { requestRender: vi.fn() },
+			skillCommands: new Map<string, string>(),
+			session: {
+				isStreaming: true,
+				isCompacting: false,
+				isBashRunning: false,
+				isEvalRunning: false,
+				extensionRunner: undefined,
+				prompt,
+			},
+			loopModeEnabled: false,
+			compactionQueuedMessages: [],
+			locallySubmittedUserSignatures: new Set<string>(),
+			updatePendingMessagesDisplay: vi.fn(),
+			showError: vi.fn(),
+			withLocalSubmission: async (_text: string, fn: () => unknown) => fn(),
+		} as unknown as InteractiveModeContext;
+
+		await new InputController(ctx).handleFollowUp();
+
+		expect(prompt).toHaveBeenCalledTimes(1);
+		const call = prompt.mock.calls[0];
+		if (!call) throw new Error("expected session.prompt to be called");
+		expect(call[0]).toBe(expanded);
+		expect(call[0]).not.toContain("[Paste #");
+		expect(call[1]?.streamingBehavior).toBe("followUp");
+	});
+
+	it("expands [Paste #N] markers when idle (not streaming)", async () => {
+		const expanded = "queued-paste-body\nspans multiple lines";
+		let editorText = "[Paste #2, +2 lines]";
+		const prompt = vi.fn(async (_text: string, _options?: PromptOptionsLike) => {});
+		const ctx = {
+			editor: {
+				setText(text: string) {
+					editorText = text;
+				},
+				getText: () => editorText,
+				getExpandedText: () =>
+					editorText.replace(/\[Paste #2(?:, (?:\+\d+ lines|\d+ chars))?\]/g, expanded),
+				addToHistory: vi.fn(),
+				pendingImages: [],
+				pendingImageLinks: [],
+				clearDraft(text?: string) {
+					if (text !== undefined) this.addToHistory(text);
+					this.setText("");
+				},
+			},
+			ui: { requestRender: vi.fn() },
+			skillCommands: new Map<string, string>(),
+			session: {
+				isStreaming: false,
+				isCompacting: false,
+				isBashRunning: false,
+				isEvalRunning: false,
+				extensionRunner: undefined,
+				prompt,
+			},
+			loopModeEnabled: false,
+			compactionQueuedMessages: [],
+			locallySubmittedUserSignatures: new Set<string>(),
+			updatePendingMessagesDisplay: vi.fn(),
+			showError: vi.fn(),
+			withLocalSubmission: async (_text: string, fn: () => unknown) => fn(),
+		} as unknown as InteractiveModeContext;
+
+		await new InputController(ctx).handleFollowUp();
+
+		expect(prompt).toHaveBeenCalledTimes(1);
+		const call = prompt.mock.calls[0];
+		if (!call) throw new Error("expected session.prompt to be called");
+		expect(call[0]).toBe(expanded);
+		expect(call[0]).not.toContain("[Paste #");
+		expect(call[1]?.streamingBehavior).toBeUndefined();
+	});
+});

packages/coding-agent/test/input-controller-keybindings.test.ts

@@ -26,6 +26,7 @@ type FakeEditor = {
 	onSubmit?: (text: string) => Promise<void>;
 	setText(text: string): void;
 	getText(): string;
+	getExpandedText(): string;
 	addToHistory(text: string): void;
 	setActionKeys(action: string, keys: string[]): void;
 	setCustomKeyHandler(key: string, handler: () => void): void;
@@ -105,6 +106,9 @@ async function createContext() {
 		getText() {
 			return editorText;
 		},
+		getExpandedText() {
+			return editorText;
+		},
 		addToHistory: vi.fn(),
 		pasteText(text: string) {
 			editorText += text;

packages/coding-agent/test/input-controller-skill-queue.test.ts

@@ -27,6 +27,7 @@ import { TempDir } from "@oh-my-pi/pi-utils";
 type StubEditor = {
 	setText: (text: string) => void;
 	getText: () => string;
+	getExpandedText: () => string;
 	clearDraft: (historyText?: string) => void;
 	addToHistory: Mock<(...args: unknown[]) => unknown>;
 	onSubmit?: (text: string) => Promise<void>;
@@ -67,6 +68,9 @@ function createStubInputControllerContext(opts: {
 		getText() {
 			return editorText;
 		},
+		getExpandedText() {
+			return editorText;
+		},
 		clearDraft(historyText?: string) {
 			if (historyText !== undefined) this.addToHistory(historyText);
 			this.setText("");