794323 - Remove the legacy JSON parsing mode once a Firefox release happens that doesn't support upgrading from a 3.6 profile

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jeff Walden [:Waldo]]

In bug 589664 I had to add a "legacy" parsing mode to the new JSON parser, so that we could parse "JSON" for Places data stored in Firefox 3.6 and earlier profiles.  (That data was sometimes incorrectly generated with a single trailing comma in its array syntax -- ["foo",] for example -- and at the time JSON.parse wrongly accepted this.)  This legacy mode is only used by Places data loading.  Once we no longer support upgrading from a Firefox 3.6 profile we can remove it.

Do we support loading data from a 3.6 profile any more?  If we do, how much longer until we'll stop doing so?  (And would 3.6 users actually get updated to the newest releases without being directed through some intermediate version first?  If they were updated to 10, say, profile loading then would fix the data so that, say, Firefox 18 could load it.)  I'm told if we're not there yet, we're really really close, so it seems worth actually filing a bug on this now.

Removing this mode is low priority, but good to do nonetheless as modes are kind of a pain to support, and it'd be nice to remove the JS_FRIEND_API we added so that legacy-mode parsing could be exposed, but not too exposed.

Comment 1

[Masatoshi Kimura [:emk]]

According to a SUMO article, we don't support direct update from Firefox 3.6 anymore.
https://support.mozilla.org/en-US/kb/firefox-just-updated-why-it-asking-me-update-again

Comment 2

[Jeff Walden [:Waldo]]

Attachment: Likely patch

Yeah, IRC conversation yesterday suggested that.  A prior attempt at a patch here failed on a few things:

https://tbpl.mozilla.org/?tree=Try&rev=0ede0a4affbd

...but I'm pretty sure I've fixed all the issues pointed out there in this patch:

https://tbpl.mozilla.org/?tree=Try&rev=0b9bc9bca2cf

Luke for the code changes and stuff, Marco for the places/bookmarks changes, jlebar for the nsJSON bits.  Or something.  Mostly this is straightforward code removal.  \o/

Comment 3

[Justin Lebar (not reading bugmail)]

Comment on attachment 753909 [details] [diff] [review]
Likely patch

Well, that's hard to argue with.

Comment 4

[Luke Wagner [:luke]]

Comment on attachment 753909 [details] [diff] [review]
Likely patch

and how!

Comment 5

[Jeff Walden [:Waldo]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/aefb412ae7f3

Comment 6

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/aefb412ae7f3