Created attachment 672057 [details] [diff] [review] parsefix.patch I've been seeing occasional failures with json.parse in the frameworker ClientPort class, and couldn't figure out a repro for it. Then with reload, Pam started running into it and had to work around it. I finally chased it down to pending messages on the ports. fw_AbstractPort_onmessage first parses the json it receives, then if there is no handler it sticks that object in pending messages When the port connects, it grabs the pending messages and calls fw_AbstractPort_onmessage again, but passing an object rather than a string. with reload, content area's are more likely to create pending messages while the frameworker is reloading, thus easier to reproduce, and more likely to be a problem. The attachement looks like the correct fix to me, but the port stuff is pretty involved, will ask Mark to look.
Comment on attachment 672057 [details] [diff] [review] parsefix.patch I agree that looks correct but think we need a test :) So IIUC, to see this you will need to have a port which is connected but which has not yet set an onmessage handler when a message arrives? Our tests probably don't do that, but it shouldn't be too hard to arrange in browser_frameworker?
Created attachment 672100 [details] [diff] [review] parsefix.patch https://tbpl.mozilla.org/?tree=Try&rev=3e86045e2829
Comment on attachment 672100 [details] [diff] [review] parsefix.patch good catch
Comment on attachment 672100 [details] [diff] [review] parsefix.patch [Triage Comment] a+ for 17/18 given that it's a social-specific, simple fix
Please land to branches by EOD Pacific time on Monday so we're sure to get this into 17.0 Beta 3
Beta 3 and Aurora missed despite the approval!
(In reply to Scoobidiver from comment #8) > Beta 3 and Aurora missed despite the approval! It's ok - I checked with gavin in irc ahead of time, we can take this in Beta 4 - please land this asap though, since it does have approval.
Marking verified fixed since this landed with tests. Please add verifyme keyword if there's something you need QA to test.