Upgrade to CodeMirror 3.23.

Review Request #6156 — Created July 28, 2014 and submitted — Latest diff uploaded


Review Board


This release fixes some issues with Markdown and some issues with
editing JSON payloads (needed for the upcoming API token policy editor).

This is not the latest CodeMirror, but we had issues with the 4.x series
(4.2, specifically) last time we tried it. There's a 3.24 release, but
it's not on the online minifier yet.

The build of CodeMirror is also updated to support JSON/JavaScript
modes, and to support optional linting and brace matching.

Tested long text and several edits on the review request page. Didn't hit
any problems.

Tested with the new API token policy editor.