Fix shortcuts double-emitting from browser on Mac

[kycutler]

No description provided.

[vs-code-engineering]

📬 CODENOTIFY

The following users are being notified based on files changed in this PR:

@jruales

Matched files:

• src/vs/platform/browserView/electron-browser/preload-browserView.ts

[Copilot]

Pull request overview

Adjusts keyboard event forwarding from the Integrated Browser (BrowserView) preload script to avoid shortcut handling being triggered both by the embedded page/browser and by VS Code—particularly on macOS.

Changes:

• Refines which keydown events are forwarded to the workbench (modifier-based + “non-editing” keys).
• Adds special-casing to keep common clipboard/editing shortcuts handled natively by the browser.
• Prevents/stops propagation for forwarded events to avoid native handling (and potential double-execution).

Comments suppressed due to low confidence (3)

src/vs/platform/browserView/electron-browser/preload-browserView.ts:61

• The Alt-key filtering only excludes altKey when ctrlKey/metaKey are false. On Windows/Linux keyboard layouts, AltGr is commonly reported as Ctrl+Alt; with the current logic those keydowns will be forwarded and preventDefault() will run, likely breaking typing of AltGr characters in page inputs. Consider detecting AltGraph via event.getModifierState?.('AltGraph') (or a similar AltGr heuristic) and treating it like plain character input (do not forward / do not preventDefault).

		// Alt+Key special character handling (Alt + Numpad keys on Windows/Linux, Alt + any key on Mac)
		if (event.altKey && !event.ctrlKey && !event.metaKey) {
			if (isMac || /^Numpad\d+$/.test(event.code)) {
				return;
			}
		}

src/vs/platform/browserView/electron-browser/preload-browserView.ts:77

• The allowlist for “native shortcuts” is currently limited to a/c/v/x/z (+shift variants) and redo on Win/Linux. This means common text-editing/navigation shortcuts like Cmd/Ctrl+Arrow (home/end/word navigation), Cmd/Ctrl+Backspace/Delete, etc. will now be forwarded and preventDefault()'d, which can break expected editing behavior in web page inputs/contenteditable elements. Consider skipping forwarding/preventDefault when the event target is editable, or expand the native-shortcut allowlist to include these editing/navigation combinations.

		// Allow native shortcuts (copy, paste, cut, undo, redo, select all) to be handled by the browser
		const ctrlCmd = isMac ? event.metaKey : event.ctrlKey;
		if (ctrlCmd && !event.altKey) {
			const key = event.key.toLowerCase();
			if (!event.shiftKey && (key === 'a' || key === 'c' || key === 'v' || key === 'x' || key === 'z')) {
				return;
			}
			if (event.shiftKey && (key === 'v' || key === 'z')) {
				return;
			}
			// Ctrl+Y is redo on Windows/Linux
			if (!event.shiftKey && key === 'y' && !isMac) {
				return;
			}
		}

src/vs/platform/browserView/electron-browser/preload-browserView.ts:55

• isMac detection uses navigator.platform, which is deprecated and can be influenced by the page environment. Since this preload already has Node/Electron access, prefer process.platform === 'darwin' for a stable platform check.

		const isMac = navigator.platform.indexOf('Mac') >= 0;