Issue 6035 - Only use openResource API when it's supported

devtools-panel.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 79 matching lines @@
   if (request.url)
   {
     urlElement.textContent = request.url;
     urlElement.setAttribute("href", request.url);
 
     // Firefox 57 doesn't support the openResource API.
     if (request.type != "POPUP" && "openResource" in ext.devtools.panels)
     {
       urlElement.addEventListener("click", event =>
       {
-        ext.devtools.panels.openResource(request.url);
-        event.preventDefault();

[Wladimir Palant, 2017/11/14 15:22:40]

Wait, won't this handle middle-clicks as well in Chrome? I guess we should only
handle `event.button == 0` and keep the default action for other buttons.

[kzar, 2017/11/14 15:33:43]

Well I just tested that and our event only fires for left clicks, but it seems
silly to assume that'll always be the case. Done.

+        if (event.button == 0)
+        {
+          ext.devtools.panels.openResource(request.url);
+          event.preventDefault();
+        }
       }, false);
     }
   }
 
   if (filter)
   {
     let filterElement = row.querySelector(".filter");
     let originElement = row.querySelector(".origin");
 
     filterElement.textContent = filter.text;
@@ skipping 140 matching lines @@
         break;
     }
   });
 
   // Since Chrome 54 the themeName is accessible, for earlier versions we must
   // assume the default theme is being used.
   // https://bugs.chromium.org/p/chromium/issues/detail?id=608869
   let theme = browser.devtools.panels.themeName || "default";
   document.body.classList.add(theme);
 }, false);