FF - Fix updates from the exclusions popup

This stops |Exclusions| from holding a reference to the |value|
parameter passed to |Settings.set|. In Firefox, this object is garbage
collected when the owning context (the exclusions popup) is closed.

The fix for all such cases in the future is to switch to using
|Settings.get|, which implicitly does |JSON.parse JSON.stringify value|
and thus returns an object in the same context as |Settings|.

We could fix this generally by doing this for the
|Settings.performPostUpdateHook| call in |Settings.set| instead.
However, I'm not convinced that it warrants the overhead of a
|JSON.parse| for every |Settings.set| call.

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/settings.coffee b/lib/settings.coffee
index 9fa27c5f..08986723 100644
--- a/lib/settings.coffee
+++ b/lib/settings.coffee
@@ -89,6 +89,9 @@ Settings =
         # Remove options installed by the "copyNonDefaultsToChromeStorage-20150717" migration; see below.
         @log "   chrome.storage.local.remove(#{key})"
         chrome.storage.local.remove key
+    # NOTE(mrmr1993): In FF, |value| will be garbage collected when the page owning it is unloaded.
+    # Any postUpdateHooks that can be called from the options page/exclusions popup should be careful not to
+    # use |value| asynchronously, or else it may refer to a |DeadObject| and accesses will throw an error.
     @performPostUpdateHook key, value
 
   clear: (key) ->