fix(android): fall back to per-user package listing when output is empty

`executeShellCommand` never rejects on a non-zero exit code, so catching
an error around `pm list packages` could not detect the SecurityException
some Samsung devices raise for the Secure Folder user (150). Detect the
failure from the empty package output instead, list packages per user,
deduplicate the result, and keep using the per-user path for the rest of
the session since the installed-apps check is polled frequently.

Author: rigor789

lib/common/mobile/android/android-application-manager.ts

@@ -23,6 +23,7 @@ import {
 export class AndroidApplicationManager extends ApplicationManagerBase {
 	public PID_CHECK_INTERVAL = 100;
 	public PID_CHECK_TIMEOUT = 10000; // 10 secs
+	private listPackagesPerUser = false;
 
 	constructor(
 		private adb: Mobile.IDeviceAndroidDebugBridge,
@@ -42,61 +43,55 @@ export class AndroidApplicationManager extends ApplicationManagerBase {
 	}
 
 	public async getInstalledApplications(): Promise<string[]> {
-		let result = "";
-		try {
-			result = await this.adb.executeShellCommand(["pm", "list", "packages"]);
-		} catch (err) {
-			/**
-			 * on some devices (Samsung) listing packages is prevented by a permission error
-			 * notably, some system apps (bloatware) is installed under user 150
-			 * and listing these packages results in a permission error.
-			 * if this happens, we have to first list all the users, and then loop through
-			 * all the users and trying to list packages for that specific user, ignoring
-			 * any errors. These are all then concatenated together and parsed normally.
-			 * This is a slower operation, so we only do it in case listing failed in the first place.
-			 */
-			const userIDs: string[] = [];
-			const users = await this.adb.executeShellCommand(["pm", "list", "users"]);
-			/**
-			 * Users:
-			 *   UserInfo{0:Owner:c13} running
-			 */
-
-			const userIDRegex = /UserInfo{(\d+)[:}]/;
-			users.split(EOL).forEach((line: string) => {
-				const [, userID] = line.match(userIDRegex) ?? [];
-
-				if (userID) {
-					userIDs.push(userID);
-				}
-			});
-
-			for (let id of userIDs) {
-				try {
-					result +=
-						EOL +
-						(await this.adb.executeShellCommand([
-							"pm",
-							"list",
-							"packages",
-							"--user",
-							id,
-						]));
-				} catch (err) {
-					// ignore - likely permission denied.
-				}
+		if (!this.listPackagesPerUser) {
+			const packages = this.parsePackageList(
+				await this.adb.executeShellCommand(["pm", "list", "packages"]),
+			);
+			if (packages.length) {
+				return packages;
 			}
 		}
+
+		// Listing without `--user` walks every user and prints nothing when shell
+		// is denied access to one of them (e.g. Samsung's Secure Folder, user 150)
+		// without rejecting. Listing per user only loses the inaccessible ones.
+		this.listPackagesPerUser = true;
+		const packages: string[] = [];
+		for (const userId of await this.getUserIds()) {
+			packages.push(
+				...this.parsePackageList(
+					await this.adb.executeShellCommand([
+						"pm",
+						"list",
+						"packages",
+						"--user",
+						userId,
+					]),
+				),
+			);
+		}
+
+		return _.uniq(packages);
+	}
+
+	private parsePackageList(output: string): string[] {
 		const regex = /package:(.+)/;
-		return result
+		return (output || "")
 			.split(EOL)
-			.map((packageString: string) => {
-				const match = packageString.match(regex);
+			.map((line: string) => {
+				const match = line.match(regex);
 				return match ? match[1] : null;
 			})
 			.filter((parsedPackage: string) => parsedPackage !== null);
 	}
 
+	private async getUserIds(): Promise<string[]> {
+		const output: string =
+			(await this.adb.executeShellCommand(["pm", "list", "users"])) || "";
+		const regex = /UserInfo\{(\d+):/g;
+		return Array.from(output.matchAll(regex), (match) => match[1]);
+	}
+
 	@hook("install")
 	public async installApplication(
 		packageFilePath: string,