From df66ebd82a1daa034823a05f58880049ea7e388d Mon Sep 17 00:00:00 2001
From: Demetrio Girardi <dgirardi@prebid.org>
Date: Thu, 3 Oct 2024 07:45:07 -0700
Subject: [PATCH] Fix exception on __pb_locator__ lookup (#236)

---
 src/messaging.js            |  6 ++++--
 test/spec/messaging_spec.js | 33 ++++++++++++++++++++++++---------
 2 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/src/messaging.js b/src/messaging.js
index c047fff..58a43c4 100644
--- a/src/messaging.js
+++ b/src/messaging.js
@@ -14,8 +14,10 @@ export function prebidMessenger(publisherURL, win = window) {
     }
 
     let target = win.parent;
-    while (target != null && target !== win.top && !isPrebidWindow(target)) target = target.parent;
-    if (!isPrebidWindow(target)) target = win.parent;
+    try {
+        while (target != null && target !== win.top && !isPrebidWindow(target)) target = target.parent;
+        if (!isPrebidWindow(target)) target = win.parent;
+    } catch (e) {}
 
     return function sendMessage(message, onResponse) {
         if (prebidDomain == null) {
diff --git a/test/spec/messaging_spec.js b/test/spec/messaging_spec.js
index 71b7879..a7dd94b 100644
--- a/test/spec/messaging_spec.js
+++ b/test/spec/messaging_spec.js
@@ -67,21 +67,36 @@ describe('prebidMessenger',() => {
                     }
                 };
             })
-            it('should post to first ancestor that has a __pb_locator__ child', () => {
-                [target, target.parent].forEach(win => {
-                    win.frames = {
-                        __pb_locator__: {}
-                    };
+            Object.entries({
+                throws() { throw new DOMException() },
+                'does not throw'() { return {} }
+            }).forEach(([t, getFrames]) => {
+                describe(`when ancestor ${t}`, () => {
+                    beforeEach(() => {
+                        Object.defineProperty(target.parent.parent, 'frames', {get: getFrames});
+                    })
+                    it('should post to first ancestor that has a __pb_locator__ child', () => {
+                        [target, target.parent].forEach(win => {
+                            win.frames = {
+                                __pb_locator__: {}
+                            };
+                        })
+                        sendMessage('test');
+                        sinon.assert.called(target.postMessage);
+                    });
                 })
-                sendMessage('test');
-                sinon.assert.calledWith(target.postMessage);
-            });
+            })
             it('should post to immediate parent when no ancestor has __pb_locator__', () => {
                 win.parent.postMessage = sinon.spy();
                 delete target.postMessage;
                 sendMessage('test');
-                sinon.assert.calledWith(win.parent.postMessage);
+                sinon.assert.called(win.parent.postMessage);
             });
+            it('should post to first restricted frame if no __pb_locator__ can be found', () => {
+                Object.defineProperty(target, 'frames', {get() { throw new DOMException() }});
+                sendMessage('test');
+                sinon.assert.called(target.postMessage)
+            })
         });
 
         it('should not run callback on response if origin does not mach', ()=> {