Fix T3 Connect callback ownership detection

CHANGELOG.md

@@ -12,6 +12,9 @@ All notable user-visible changes are documented here. This project follows
   its complete license inventory.
 - Limited desktop callback registration to the active T3 Connect login window
   and restored the previous scheme owner before removing the hidden handler.
+- Made callback ownership use explicit user MIME associations, preventing an
+  `xdg-utils` cache fallback from opening T3 Code instead of completing login,
+  while preserving handler changes made during the login window.
 - Made approval-required the per-task default and added an explicit warning
   confirmation before a new task can use broader runtime access.
 - Made the marketplace SEA checkout-path-independent and added a CI-enforced

README.md

@@ -114,8 +114,11 @@ Clerk client token, pending callback secret, and DPoP private material in
 Secret Service, plus the selected environment under the user's XDG state
 directory. Choosing **Sign in with T3 Connect** explicitly creates a hidden
 desktop callback entry and temporarily claims `t3code://`; both the entry and
-the prior scheme-owner change are reversed when that login window closes.
-Installation requires no privilege escalation and runs no remote build.
+the prior scheme-owner change are reversed when that login window closes. The
+bridge does not edit T3 Code's desktop entry, and it only restores the prior
+owner if the plugin still owns the scheme. A later login replaces and removes
+any plugin callback entry left by an interrupted attempt. Installation requires
+no privilege escalation and runs no remote build.
 
 The root [LICENSE](LICENSE), [THIRD_PARTY_NOTICES.md](THIRD_PARTY_NOTICES.md),
 and [licenses](licenses/) inventory cover the plugin, embedded Node runtime,
@@ -219,9 +222,12 @@ The full real-account procedure is in [docs/ACCEPTANCE.md](docs/ACCEPTANCE.md).
 ## Troubleshooting
 
 - **Browser returns to the wrong T3 application:** retry from the panel and
-  verify `xdg-mime` can update the user's MIME associations. The bridge creates
-  its hidden desktop entry only for the active login window and restores any
-  previous `t3code` handler afterward.
+  verify `xdg-mime` can update the user's MIME associations. If `xdg-mime query
+  default x-scheme-handler/t3code` and `gio mime x-scheme-handler/t3code`
+  disagree, an older `xdg-utils` may be reporting a cache fallback. The bridge
+  uses the explicit user association for ownership checks, creates its hidden
+  desktop entry only for the active login window, and restores the prior owner
+  afterward.
 - **Secret store unavailable:** verify `secret-tool lookup application
   io.github.digitalpals.omarchy-t3code item t3-connect-clerk-client >/dev/null` can reach
   an unlocked Secret Service. Do not print its value or replace it with a

bridge/src/auth/protocolHandler.ts

@@ -23,6 +23,7 @@ export interface ProtocolHandlerOptions {
   desktopId?: string;
   registerDesktop?: () => Promise<() => Promise<void>>;
   clearDefault?: () => Promise<void>;
+  configuredOwners?: () => Promise<string[] | null>;
 }
 
 function runXdgMime(args: string[]): Promise<CommandResult> {
@@ -90,12 +91,13 @@ function xdgRoots(environment: NodeJS.ProcessEnv = process.env): {
       throw new BridgeError("AUTH_CALLBACK_REGISTRATION_FAILED", "Desktop callback paths must be absolute.");
     }
   }
+  const dataApplications = join(data, "applications");
   return {
-    applications: join(data, "applications"),
+    applications: dataApplications,
     mimeapps: [...new Set([
       join(config, "mimeapps.list"),
       join(config, "applications", "mimeapps.list"),
-      join(data, "applications", "mimeapps.list"),
+      join(dataApplications, "mimeapps.list"),
     ])],
   };
 }
@@ -154,29 +156,48 @@ export async function installT3CallbackDesktop(
   const { applications } = xdgRoots(environment);
   const desktopPath = join(applications, CALLBACK_DESKTOP_ID);
   await mkdir(applications, { recursive: true, mode: 0o700 });
-  let previous: Buffer | null = null;
-  let previousMode = 0o644;
-  try {
-    [previous, previousMode] = await Promise.all([
-      readFile(desktopPath),
-      stat(desktopPath).then((value) => value.mode & 0o777),
-    ]);
-  } catch (error) {
-    if ((error as NodeJS.ErrnoException).code !== "ENOENT") throw error;
-  }
   await atomicWrite(desktopPath, desktopEntry(command), 0o644);
   await refreshDesktopDatabase(applications);
 
   let removed = false;
   return async (): Promise<void> => {
     if (removed) return;
     removed = true;
-    if (previous === null) await rm(desktopPath, { force: true });
-    else await atomicWrite(desktopPath, previous, previousMode);
+    await rm(desktopPath, { force: true });
     await refreshDesktopDatabase(applications);
   };
 }
 
+function configuredOwners(contents: string): string[] | null {
+  let defaults = false;
+  for (const line of contents.split(/\r?\n/u)) {
+    const section = line.trim();
+    if (section.startsWith("[") && section.endsWith("]")) {
+      defaults = section === "[Default Applications]";
+      continue;
+    }
+    if (!defaults) continue;
+    const match = line.match(/^\s*x-scheme-handler\/t3code\s*=\s*(.*)$/u);
+    if (!match) continue;
+    return (match[1] ?? "").split(";").map((owner) => owner.trim()).filter(Boolean);
+  }
+  return null;
+}
+
+export async function configuredT3ProtocolOwners(
+  environment: NodeJS.ProcessEnv = process.env,
+): Promise<string[] | null> {
+  for (const path of xdgRoots(environment).mimeapps) {
+    try {
+      const owners = configuredOwners(await readFile(path, "utf8"));
+      if (owners !== null) return owners;
+    } catch (error) {
+      if ((error as NodeJS.ErrnoException).code !== "ENOENT") throw error;
+    }
+  }
+  return null;
+}
+
 function withoutDesktopAssociation(contents: string, desktopId: string): string {
   const hadFinalNewline = contents.endsWith("\n");
   const lines = contents.split(/\r?\n/u);
@@ -219,19 +240,31 @@ export async function activateT3ProtocolHandler(
 ): Promise<() => Promise<void>> {
   const command = options.command ?? runXdgMime;
   const desktopId = options.desktopId ?? CALLBACK_DESKTOP_ID;
-  const removeDesktop = await (options.registerDesktop ?? installT3CallbackDesktop)();
+  const inspectConfiguredOwners = options.configuredOwners ?? configuredT3ProtocolOwners;
   const clearDefault = options.clearDefault ?? (() => clearT3ProtocolDefault(desktopId));
   let previous = "";
+  let removeDesktop = async (): Promise<void> => undefined;
+
+  const currentOwner = async (): Promise<string> => {
+    const owners = await inspectConfiguredOwners();
+    return owners?.[0] ?? await queryDefault(command);
+  };
   const restoreOwner = async (): Promise<void> => {
-    if (await queryDefault(command) !== desktopId) return;
+    if (await currentOwner() !== desktopId) return;
     if (previous.length > 0 && previous !== desktopId) await setDefault(command, previous);
     else await clearDefault();
   };
 
   try {
-    previous = await queryDefault(command);
-    if (previous !== desktopId) await setDefault(command, desktopId);
-    const active = await queryDefault(command);
+    const configured = await inspectConfiguredOwners();
+    previous = configured?.find((owner) => owner !== desktopId) ?? "";
+    if (previous.length === 0) {
+      const queried = await queryDefault(command);
+      if (queried !== desktopId) previous = queried;
+    }
+    removeDesktop = await (options.registerDesktop ?? installT3CallbackDesktop)();
+    await setDefault(command, desktopId);
+    const active = await currentOwner();
     if (active !== desktopId) {
       throw new BridgeError(
         "AUTH_CALLBACK_REGISTRATION_FAILED",

lib/t3-mini-bridge-linux-x64.sha256

@@ -1 +1 @@
-cc00a3e17f4c90ab70a01768f97288941f5370371e1fc232dc167b6daebb7378  t3-mini-bridge
+16c5402d30713506e185289a5440936d45d7b89a66ab98ea4301a873587ea4bf  t3-mini-bridge

tests/auth.test.ts

@@ -12,7 +12,9 @@ import { NativeClerkProvider } from "../bridge/src/auth/nativeProvider.ts";
 import { makePkceRequest, stateMatches } from "../bridge/src/auth/pkce.ts";
 import {
   activateT3ProtocolHandler,
+  CALLBACK_DESKTOP_ID,
   clearT3ProtocolDefault,
+  configuredT3ProtocolOwners,
   installT3CallbackDesktop,
   type MimeCommand,
 } from "../bridge/src/auth/protocolHandler.ts";
@@ -318,70 +320,97 @@ test("native callback forwarding rejects unexpected schemes and missing pending
   );
 });
 
-test("T3 callback handler temporarily preserves an existing desktop owner", async () => {
-  let current = "t3code-nightly.desktop";
+test("T3 callback handler ignores a misleading xdg fallback and restores the explicit owner", async () => {
+  let configured = ["t3code-nightly.desktop"];
   const calls: string[][] = [];
   const command: MimeCommand = async (args) => {
     calls.push(args);
-    if (args[0] === "query") return { code: 0, stdout: `${current}\n`, stderr: "" };
+    if (args[0] === "query") return { code: 0, stdout: `${CALLBACK_DESKTOP_ID}\n`, stderr: "" };
     assert.equal(args[0], "default");
-    current = args[1] ?? "";
+    configured = args[1] ? [args[1]] : [];
     return { code: 0, stdout: "", stderr: "" };
   };
   let desktopRemoved = false;
   const restore = await activateT3ProtocolHandler({
     command,
+    configuredOwners: async () => configured,
     registerDesktop: async () => async () => { desktopRemoved = true; },
   });
-  assert.equal(current, "io.github.digitalpals.omarchy-t3code-callback.desktop");
+  assert.deepEqual(configured, [CALLBACK_DESKTOP_ID]);
   await restore();
-  assert.equal(current, "t3code-nightly.desktop");
+  assert.deepEqual(configured, ["t3code-nightly.desktop"]);
   assert.equal(desktopRemoved, true);
-  assert(calls.some((args) => args.join(" ").includes("x-scheme-handler/t3code")));
+  assert.deepEqual(calls, [
+    ["default", CALLBACK_DESKTOP_ID, "x-scheme-handler/t3code"],
+    ["default", "t3code-nightly.desktop", "x-scheme-handler/t3code"],
+  ]);
 });
 
 test("legacy callback ownership is restored after the login window", async () => {
-  let current = "io.github.omarchy-t3code-callback.desktop";
+  let configured = ["io.github.omarchy-t3code-callback.desktop"];
   const command: MimeCommand = async (args) => {
-    if (args[0] === "query") return { code: 0, stdout: `${current}\n`, stderr: "" };
-    current = args[1] ?? "";
+    if (args[0] === "query") return { code: 0, stdout: `${configured[0] ?? ""}\n`, stderr: "" };
+    configured = args[1] ? [args[1]] : [];
     return { code: 0, stdout: "", stderr: "" };
   };
   const restore = await activateT3ProtocolHandler({
     command,
+    configuredOwners: async () => configured,
     registerDesktop: async () => async () => undefined,
   });
-  assert.equal(current, "io.github.digitalpals.omarchy-t3code-callback.desktop");
+  assert.deepEqual(configured, [CALLBACK_DESKTOP_ID]);
   await restore();
-  assert.equal(current, "io.github.omarchy-t3code-callback.desktop");
+  assert.deepEqual(configured, ["io.github.omarchy-t3code-callback.desktop"]);
 });
 
 test("callback handler clears a newly created default before removing its desktop entry", async () => {
-  let current = "";
+  let configured: string[] | null = null;
   let cleared = false;
   let removed = false;
   const command: MimeCommand = async (args) => {
-    if (args[0] === "query") return { code: 0, stdout: `${current}\n`, stderr: "" };
-    current = args[1] ?? "";
+    if (args[0] === "query") return { code: 0, stdout: "", stderr: "" };
+    configured = args[1] ? [args[1]] : [];
     return { code: 0, stdout: "", stderr: "" };
   };
   const restore = await activateT3ProtocolHandler({
     command,
-    clearDefault: async () => { current = ""; cleared = true; },
+    clearDefault: async () => { configured = null; cleared = true; },
+    configuredOwners: async () => configured,
     registerDesktop: async () => async () => { removed = true; },
   });
-  assert.equal(current, "io.github.digitalpals.omarchy-t3code-callback.desktop");
+  assert.deepEqual(configured, [CALLBACK_DESKTOP_ID]);
   await restore();
-  assert.equal(current, "");
+  assert.equal(configured, null);
   assert.equal(cleared, true);
   assert.equal(removed, true);
 });
 
+test("callback cleanup does not overwrite a handler changed during login", async () => {
+  let configured = ["t3code-nightly.desktop"];
+  let removed = false;
+  const command: MimeCommand = async (args) => {
+    if (args[0] === "query") return { code: 0, stdout: `${configured[0] ?? ""}\n`, stderr: "" };
+    configured = args[1] ? [args[1]] : [];
+    return { code: 0, stdout: "", stderr: "" };
+  };
+  const restore = await activateT3ProtocolHandler({
+    command,
+    configuredOwners: async () => configured,
+    registerDesktop: async () => async () => { removed = true; },
+  });
+  configured = ["other-t3-client.desktop"];
+  await restore();
+  assert.deepEqual(configured, ["other-t3-client.desktop"]);
+  assert.equal(removed, true);
+});
+
 test("callback desktop registration is hidden, quoted, and removed after login", async () => {
   const root = await mkdtemp(join(tmpdir(), "t3-callback-desktop-"));
   const data = join(root, "data");
   const desktop = join(data, "applications", "io.github.digitalpals.omarchy-t3code-callback.desktop");
   try {
+    await mkdir(join(data, "applications"), { recursive: true });
+    await writeFile(desktop, "stale callback entry\n");
     const removeDesktop = await installT3CallbackDesktop(
       { HOME: root, XDG_CONFIG_HOME: join(root, "config"), XDG_DATA_HOME: data },
       ["/opt/T3 Mini/t3-mini-bridge"],
@@ -397,6 +426,29 @@ test("callback desktop registration is hidden, quoted, and removed after login",
   }
 });
 
+test("configured T3 owner comes from the explicit user MIME association", async () => {
+  const root = await mkdtemp(join(tmpdir(), "t3-configured-owner-"));
+  const config = join(root, "config");
+  try {
+    await mkdir(config, { recursive: true });
+    await writeFile(join(config, "mimeapps.list"), [
+      "[Default Applications]",
+      "x-scheme-handler/t3code=t3code-url-handler.desktop;",
+      "",
+    ].join("\n"));
+    assert.deepEqual(
+      await configuredT3ProtocolOwners({
+        HOME: root,
+        XDG_CONFIG_HOME: config,
+        XDG_DATA_HOME: join(root, "data"),
+      }),
+      ["t3code-url-handler.desktop"],
+    );
+  } finally {
+    await rm(root, { recursive: true, force: true });
+  }
+});
+
 test("clearing an ephemeral callback default preserves other MIME owners", async () => {
   const root = await mkdtemp(join(tmpdir(), "t3-callback-mimeapps-"));
   const config = join(root, "config");