From e99356a04bd277ee4fb8e85276365fef318ada1a Mon Sep 17 00:00:00 2001
From: webadderall <balls@balls.com>
Date: Sat, 6 Jun 2026 20:01:19 +1000
Subject: [PATCH] fix(linux): preserve portal screen source mapping

---
 electron/ipc/register/sourceMapping.test.ts | 50 +++++++++++++++++++++
 electron/ipc/register/sourceMapping.ts      | 35 +++++++++++++++
 electron/ipc/register/sources.ts            |  8 +++-
 3 files changed, 92 insertions(+), 1 deletion(-)
 create mode 100644 electron/ipc/register/sourceMapping.test.ts
 create mode 100644 electron/ipc/register/sourceMapping.ts

diff --git a/electron/ipc/register/sourceMapping.test.ts b/electron/ipc/register/sourceMapping.test.ts
new file mode 100644
index 00000000..d0b68e75
--- /dev/null
+++ b/electron/ipc/register/sourceMapping.test.ts
@@ -0,0 +1,50 @@
+import { describe, expect, it } from "vitest";
+
+import {
+	getScreenSourceIdForDisplay,
+	LINUX_PORTAL_SCREEN_SOURCE_ID,
+} from "./sourceMapping";
+
+describe("getScreenSourceIdForDisplay", () => {
+	it("keeps the live Electron screen source when one is available", () => {
+		expect(
+			getScreenSourceIdForDisplay({
+				displayId: "42",
+				matchedSourceId: "screen:42:0",
+				platform: "linux",
+			}),
+		).toBe("screen:42:0");
+	});
+
+	it("routes unmatched Linux Wayland screens through the portal sentinel", () => {
+		expect(
+			getScreenSourceIdForDisplay({
+				displayId: "42",
+				env: { XDG_SESSION_TYPE: "wayland", WAYLAND_DISPLAY: "wayland-0" },
+				matchedSourceId: null,
+				platform: "linux",
+			}),
+		).toBe(LINUX_PORTAL_SCREEN_SOURCE_ID);
+	});
+
+	it("keeps unmatched Linux X11 screens on the explicit fallback id", () => {
+		expect(
+			getScreenSourceIdForDisplay({
+				displayId: "42",
+				env: { XDG_SESSION_TYPE: "x11", DISPLAY: ":0" },
+				matchedSourceId: null,
+				platform: "linux",
+			}),
+		).toBe("screen:fallback:42");
+	});
+
+	it("keeps non-Linux unmatched screens on the explicit fallback id", () => {
+		expect(
+			getScreenSourceIdForDisplay({
+				displayId: "42",
+				matchedSourceId: undefined,
+				platform: "win32",
+			}),
+		).toBe("screen:fallback:42");
+	});
+});
\ No newline at end of file
diff --git a/electron/ipc/register/sourceMapping.ts b/electron/ipc/register/sourceMapping.ts
new file mode 100644
index 00000000..a61b4cf7
--- /dev/null
+++ b/electron/ipc/register/sourceMapping.ts
@@ -0,0 +1,35 @@
+export const LINUX_PORTAL_SCREEN_SOURCE_ID = "screen:linux-portal";
+
+export function isLikelyLinuxWaylandSession(env: NodeJS.ProcessEnv) {
+	const sessionType = env.XDG_SESSION_TYPE?.trim().toLowerCase();
+	if (sessionType === "wayland") {
+		return true;
+	}
+	if (sessionType === "x11") {
+		return false;
+	}
+
+	return Boolean(env.WAYLAND_DISPLAY);
+}
+
+export function getScreenSourceIdForDisplay({
+	displayId,
+	env = process.env,
+	matchedSourceId,
+	platform,
+}: {
+	displayId: string;
+	env?: NodeJS.ProcessEnv;
+	matchedSourceId?: string | null;
+	platform: NodeJS.Platform | string;
+}) {
+	if (matchedSourceId) {
+		return matchedSourceId;
+	}
+
+	if (platform === "linux" && isLikelyLinuxWaylandSession(env)) {
+		return LINUX_PORTAL_SCREEN_SOURCE_ID;
+	}
+
+	return `screen:fallback:${displayId}`;
+}
\ No newline at end of file
diff --git a/electron/ipc/register/sources.ts b/electron/ipc/register/sources.ts
index 4ba6b35a..33c9ee74 100644
--- a/electron/ipc/register/sources.ts
+++ b/electron/ipc/register/sources.ts
@@ -6,6 +6,7 @@ import { selectedSource, setSelectedSource } from "../state";
 import type { SelectedSource } from "../types";
 import { getScreen, parseWindowId } from "../utils";
 import { getDisplayBoundsForSource, getDisplayWorkAreaForSource } from "../recording/ffmpeg";
+import { getScreenSourceIdForDisplay } from "./sourceMapping";
 import {
 	getNativeMacWindowSources,
 	resolveMacWindowBounds,
@@ -125,7 +126,12 @@ export function registerSourceHandlers({
 					: `Screen ${index + 1}`;
 
 			return {
-				id: matchedSource?.id ?? `screen:fallback:${displayId}`,
+				id: getScreenSourceIdForDisplay({
+					displayId,
+					env: process.env,
+					matchedSourceId: matchedSource?.id,
+					platform: process.platform,
+				}),
 				name: displayName,
 				originalName: matchedSource?.name ?? displayName,
 				display_id: displayId,