343508 - Calling setProperty on a rule in a resource: stylesheet asserts "container didn't take ownership: 'Not Reached'"

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect, P3)

Description

[Jason Barnabe (np)]

1. Open DOMI on any document.
2. Select the BODY element.
3. Switch the right side to the stylesheet view
4. Select the first rule (resource://gre/res/html.css)
5. Change margin-top to something else

Result:

WARNING: NS_ENSURE_TRUE(index != -1) failed: file /home/np/mozilla/layout/style/nsCSSStyleSheet.cpp, line 1082
###!!! ASSERTION: container didn't take ownership: 'Not Reached', file /home/np/mozilla/layout/style/nsCSSStyleRule.cpp, line 977
************************************************************
* Call to xpconnect wrapped JSObject produced this error:  *
[Exception... "Component returned failure code: 0x8000ffff (NS_ERROR_UNEXPECTED) [nsIDOMCSSStyleDeclaration.setProperty]"  nsresult: "0x8000ffff (NS_ERROR_UNEXPECTED)"  location: "JS frame :: chrome://inspector/content/viewers/styleRules/styleRules.js :: doTransaction :: line 596"  data: no]
************************************************************
JavaScript error: , line 0: uncaught exception: [Exception... "Component returned failure code: 0x8000ffff (NS_ERROR_UNEXPECTED) [nsIDOMCSSStyleDeclaration.setProperty]"  nsresult: "0x8000ffff (NS_ERROR_UNEXPECTED)"  location: "JS frame :: chrome://inspector/content/viewers/styleRules/styleRules.js :: doTransaction :: line 596"  data: no]

Comment 1

[Boris Zbarsky [:bzbarsky]]

The problem is that this is a child sheet of a sheet that gets cloned.  Editing those has Issues.

Comment 2

[Boris Zbarsky [:bzbarsky]]

This code still needs to call EnsureUniqueInner to actually work, even with bug 183348 fixed.

Comment 3

[Colby Russell :crussell (no longer Mozilla-ing)]

Is the platform for this bug really x86 Linux or All All?

Comment 4

[Boris Zbarsky [:bzbarsky]]

Fixing bug 536379 should fix this.

Comment 5

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

The UI for this now seems disabled, but I just verified very similar steps for bug 253354, so I think this is now fixed.

That said, the UA sheet, scrollbars sheet, user content sheet, user chrome sheet, forms sheet, and sheets from the style sheet service still aren't cloned in DocumentViewerImpl::CreateStyleSet, so editing them affects all documents.