Issue 6493 - Ensure Firefox draws the "Block element" popup window

lib/filterComposer.js

Index: lib/filterComposer.js
diff --git a/lib/filterComposer.js b/lib/filterComposer.js
index fe5dcdf3071e1762e31cfb4e4bd461a67bbcac23..fbd3289b666f3d701455c64078e995693a1be1df 100644
--- a/lib/filterComposer.js
+++ b/lib/filterComposer.js
@@ -188,6 +188,11 @@ port.on("composer.openDialog", (message, sender) =>
         // we must check the response too.
         if (!response)
           throw new Error();
+
+        // Sometimes Firefox doesn't draw the window's contents initially, so we
+        // resize the window slightly as a workaround.
+        // https://issues.adblockplus.org/ticket/6493
+        browser.windows.update(window.id, {width: 422});

[kzar, 2018/10/04 15:30:37]

For some reason one pixel larger wasn't enough to have Firefox redraw the
window, so I had to go with 422px.

[Sebastian Noack, 2018/10/04 18:38:55]

Would it work if we remove the width from the browser.windows.create() call, and
then resize it to the correct width here? That way we would define the width
only in one place, and we don't have to set it to a weird number like 422.

[kzar, 2018/10/08 14:50:13]

Well, I tried that but initially the width of the popup was much larger, then it
shrunk down. It looked kind of janky! 

How about this instead? I avoid hard-coding the width again, instead just add
2px (the minimum required).

       }).catch(e =>
       {
         // Firefox sometimes sets the status for a window to "complete" before