1346662 - Changes made to source-mapped CSS are reverted on save

Status: RESOLVED FIXED

(DevTools :: Style Editor, defect, P3)

Description

[gandalf3]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0
Build ID: 20170307144106

Steps to reproduce:

1. Set up a directory with an html file + sass stylesheet, with main.css linked into index.html:

.
├── index.html
├── main.css
├── main.css.map
└── scss
    └── main.scss

2. Start sass (or similar) watching for changes to scss/main.scss and regenerating main.css and main.css.map accordingly.

3. View index.html in Firefox through the filesystem (file://)

4. Open up source-mapped sass file in the style editor

5. Make a change and save it


Actual results:

Firefox correctly live-reloaded the rendered page to reflect the changes, then after about a second, reverted the changes in the style editor without updating the page.

Leaving me with my changes reflected in the rendered page, but the unchanged scss in the style editor.

Undoing brought back my changes, putting the style editor back in sync with the page.


Expected results:

Firefox should not revert changes after saving.

Comment 1

[Patrick Brosset <:pbro>]

Inspector bug triage (filter on CLIMBING SHOES).

Comment 2

[Tom Tromey :tromey]

The style editor calls the sheet actor's update method:

https://dxr.mozilla.org/mozilla-central/rev/f9a5e9ed62103c84e4cde915f4d08f1ce71be83e/devtools/server/actors/stylesheets.js#715

However, this doesn't clear out the existing source map info,
so eventually the style editor gets stale text for the original source.

It's possible to clear the source maps in |update| but I wonder what effect
that will have when, say, as-authored editing a rule.
Though probably that is already kind of broken when source maps are present.

Comment 3

[Tom Tromey :tromey]

Not only did that not work, it's also too complicated - it seems to suffice to set _isUpdating
in updateLinkedStyleSheet

Comment 4

[Tom Tromey :tromey]

Attachment: Bug 1346662 - do not revert original text after saving;

When saving an original style sheet, arrange not to reload the text
from the OriginalSourceActor afterward.  The actor will serve stale
text, but the editor knows better already.

Review commit: https://reviewboard.mozilla.org/r/179420/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/179420/

Comment 5

[Gabriel Luong [:gl] (ΦωΦ)]

Comment on attachment 8907750 [details]
Bug 1346662 - do not revert original text after saving;

https://reviewboard.mozilla.org/r/179420/#review184636

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/270740992bc6
do not revert original text after saving; r=gl

Comment 7

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/mozilla-central/rev/270740992bc6