Bug 1698526 - Ensure we call SubDialog close callbacks when closing a SubDialog that has not fully opened. r=Gijs

Differential Revision: https://phabricator.services.mozilla.com/D109063

browser/base/content/test/tabPrompts/browser_windowPrompt.js

@@ -200,3 +200,31 @@ add_task(async function test_check_multiple_prompts() {
     ok(!menu.disabled, `Menu ${menu.id} should not be disabled anymore.`);
   }
 });
+
+/**
+ * Tests that we get a closed callback even when closing the prompt before the
+ * underlying SubDialog has fully opened.
+ */
+add_task(async function test_closed_callback() {
+  await SpecialPowers.pushPrefEnv({
+    set: [["prompts.windowPromptSubDialog", true]],
+  });
+
+  let promptClosedPromise = Services.prompt.asyncAlert(
+    window.browsingContext,
+    Services.prompt.MODAL_TYPE_INTERNAL_WINDOW,
+    "Hello",
+    "Hello, World!"
+  );
+
+  let dialog = gDialogBox._dialog;
+  ok(dialog, "gDialogBox should have a dialog");
+
+  // Directly close the dialog without waiting for it to initialize.
+  dialog.close();
+
+  info("Waiting for prompt close");
+  await promptClosedPromise;
+
+  ok(!gDialogBox._dialog, "gDialogBox should no longer have a dialog");
+});

toolkit/modules/SubDialog.jsm

@@ -118,6 +118,21 @@ SubDialog.prototype = {
     });
     this._frame._dialogReady = this._dialogReady;
 
+    // Assign close callbacks sync to ensure we can always callback even if the
+    // SubDialog is closed directly after opening.
+    let dialog = null;
+
+    if (closingCallback) {
+      this._closingCallback = (...args) => {
+        closingCallback.apply(dialog, args);
+      };
+    }
+    if (closedCallback) {
+      this._closedCallback = (...args) => {
+        closedCallback.apply(dialog, args);
+      };
+    }
+
     // Wait until frame is ready to prevent browser crash in tests
     await this._frameCreated;
 
@@ -152,18 +167,12 @@ SubDialog.prototype = {
       dialogFeatures = `${features},${dialogFeatures}`;
     }
 
-    let dialog = this._window.openDialog(
+    dialog = this._window.openDialog(
       aURL,
       `dialogFrame-${this._id}`,
       dialogFeatures,
       ...aParams
     );
-    if (closingCallback) {
-      this._closingCallback = closingCallback.bind(dialog);
-    }
-    if (closedCallback) {
-      this._closedCallback = closedCallback.bind(dialog);
-    }
 
     this._closingEvent = null;
     this._isClosing = false;