Issue 6774 - $document doesn't whitelist everything inside iframes in Edge

ext/background.js

Index: ext/background.js
diff --git a/ext/background.js b/ext/background.js
index e0242e545396f8e48fdbbfea961b8cf42e14a8b9..f9ad0b655064323285e0dd14b28444f724feb6cb 100644
--- a/ext/background.js
+++ b/ext/background.js
@@ -559,10 +559,36 @@
           if (!frames)
             return null;
 
-          let frame = frames.get(rawSender.frameId);
+          let frame;
+          // In Microsoft Edge (version 42.17134.1.0) we don't have frameId
+          // so we fall back to iterating over the tab's frames
+          // see https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/11716733
+          if (rawSender.frameId != undefined)
+            frame = frames.get(rawSender.frameId);
+          else
+          {
+            for (let [key, value] of frames)

[kzar, 2018/07/17 16:54:35]

Nit: Would be nice to use some more descriptive variable names, e.g. something
like `frameId` and `frame`. Oh, `frame` is already taken actually, but you get
the idea.

[geo, 2018/07/18 16:08:11]

Done.

+            {
+              let valueHref = value.url.href.replace(/#.*/, "");

[kzar, 2018/07/17 16:54:35]

Nit: I'd consider using `String.prototype.substring` to take the part of
`value.url.href` up to the first "#", instead of using
`String.prototype.replace` with a regular expression to mutate `value.url.href`.
I'm not sure that it matters in practice though.

[geo, 2018/07/18 16:08:10]

I'm not sure either, but for `String.prototype.substring` or
`String.prototype.substr` I would need to use `String.prototype.indexOf` and
that returns `-1` if no hash is found, so I need an extra check. That's why I
went with replace.

+
+              let rawSenderHref = rawSender.url ?

[kzar, 2018/07/17 16:54:35]

Can't we do this outside of the for loop?

[geo, 2018/07/18 16:08:10]

Done.

+                rawSender.url.replace(/#.*/, "") :
+                "";
+
+              // if we have two frames with the same URL

[kzar, 2018/07/17 16:54:35]

Nit: This is a good comment, but would you mind capitalising and adding a full
stop?

[geo, 2018/07/18 16:08:10]

Done.

+              // we are going to pick the first one we find
+              // as we have no other way of distinguishing between them
+              if (valueHref == rawSenderHref)
+              {
+                frame = value;
+                this.id = key;
+                break;
+              }
+            }
+          }
+
           if (frame)
             return frame.parent || null;
-
           return frames.get(0) || null;
         }
       };