Let $.cache report connection errors.

src/General/Build.Test.coffee

@@ -66,6 +66,7 @@ Build.Test =
   testOne: (post) ->
     Build.Test.postsRemaining++
     $.cache "#{location.protocol}//a.4cdn.org/#{post.board.ID}/thread/#{post.thread.ID}.json", ->
+      return unless @response
       {posts} = @response
       Build.spoilerRange[post.board.ID] = posts[0].custom_spoiler
       for postData in posts

src/Miscellaneous/ExpandComment.coffee

@@ -38,7 +38,7 @@ ExpandComment =
   parse: (req, a, post) ->
     {status} = req
     unless status in [200, 304]
-      a.textContent = "Error #{req.statusText} (#{status})"
+      a.textContent = if status then "Error #{req.statusText} (#{status})" else 'Connection Error'
       return
 
     posts = req.response.posts

src/Miscellaneous/ExpandThread.coffee

@@ -89,7 +89,7 @@ ExpandThread =
 
   parse: (req, thread, a) ->
     if req.status not in [200, 304]
-      a.textContent = "Error #{req.statusText} (#{req.status})"
+      a.textContent = if req.status then "Error #{req.statusText} (#{req.status})" else 'Connection Error'
       return
 
     Build.spoilerRange[thread.board] = req.response.posts[0].custom_spoiler

src/classes/Fetcher.coffee

@@ -61,12 +61,14 @@ class Fetcher
     {status} = req
     unless status is 200
       # The thread can die by the time we check a quote.
-      return if @archivedPost()
+      return if status and @archivedPost()
 
       $.addClass @root, 'warning'
       @root.textContent =
         if status is 404
           "Thread No.#{@threadID} 404'd."
+        else if !status
+          'Connection Error'
         else
           "Error #{req.statusText} (#{req.status})."
       return

src/platform/$.coffee

@@ -92,12 +92,11 @@ do ->
         $.queueTask -> cb.call req, {isCached: true}
       return req
     options.onloadend = ->
-      if @status
-        for cb in @callbacks
-          do (cb) => $.queueTask => cb.call @, {isCached: false}
-        delete @callbacks
-      else
+      unless @status
         delete reqs[url]
+      for cb in @callbacks
+        do (cb) => $.queueTask => cb.call @, {isCached: false}
+      delete @callbacks
     req = $.ajax url, options
     req.callbacks = [cb]
     reqs[url] = req

src/platform/CrossOrigin.coffee

@@ -70,7 +70,7 @@ CrossOrigin =
 
   # Attempts to fetch `url` in JSON format using cross-origin privileges, if available.
   # On success, calls `cb` with a `this` containing properties `status`, `statusText`, `response` and caches result.
-  # On error/abort, calls `cb` with a `this` of `{}`.
+  # On error/abort/timeout, calls `cb` with a `this` of `{}` or in some cases an XMLHttpRequest reflecting the error.
   # If `bypassCache` is true, ignores previously cached results.
   json: do ->
     callbacks = {}
@@ -90,10 +90,7 @@ CrossOrigin =
       unless GM?.xmlHttpRequest? or GM_xmlhttpRequest?
         if bypassCache
           $.cleanCache (url2) -> url2 is url
-        if (req = $.cache url, cb)
-          $.on req, 'abort error', -> cb.call({})
-        else
-          cb.call {}
+        req = $.cache url, cb
         return
       <% } %>