1548256 - Blank debugger when hovering variables

Status: RESOLVED FIXED

(DevTools :: Debugger, defect, P1)

Description

[Julian Descottes [:jdescottes]]

Could not reproduce with webcontent so far. Happens very often when debugging xpcshell or using the Browser Toolbox.

Spawned from Bug 1544820

STRs:

• open Firefox
• open and close DevTools (that's just to load toolbox.js which we will use to repro the issue)
• open Browser Toolbox
• in Browser Toolbox, open Debugger, open toolbox.js
• set a breakpoint in the Toolbox constructor
• back to Firefox
• open DevTools (should break in the browser toolbox)
• back to the Browser Toolbox
• try to hover "ChromeUtils" on L34

This leads to a blank debugger for me. Copy pasting additional info I posted in the other bug:

I get the following exception :

console.error: (new TypeError("item is undefined", "resource://devtools/client/shared/components/reps/reps.js", 1497))
JavaScript error: resource://devtools/client/shared/components/reps/reps.js, line 1497: TypeError: item is undefined

It seems to happen when hovering some variables in the debugger source editor. The stack is (removed everything not-devtools related):

nodeHasChildren@resource://devtools/client/shared/components/reps/reps.js:1497:15
nodeIsPrimitive@resource://devtools/client/shared/components/reps/reps.js:1560:33
[...]
setPreview/<@resource://devtools/client/debugger/src/actions/preview.js:68:11
[...]
updatePreview/<@resource://devtools/client/debugger/src/actions/preview.js:62:5
[...]
Preview/this.onTokenEnter@resource://devtools/client/debugger/src/components/Editor/Preview/index.js:57:9
[...]
dispatch@resource://devtools/client/debugger/src/utils/editor/token-events.js:46:26
onMouseOver/<@resource://devtools/client/debugger/src/utils/editor/token-events.js:88:7

It seems we are trying to render an object inspector without roots?

Comment 1

[Julian Descottes [:jdescottes]]

Regression from Bug 1536116

Comment 2

[Jason Laster [:jlast]]

Attachment: Bug 1548256 - Blank debugger when hovering variables. r=davidwalsh

Comment 3

[Jason Laster [:jlast]]

Attachment: Bug 1548256 - Blank debugger when hovering variables. r=davidwalsh

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/72f117346242
Blank debugger when hovering variables. r=davidwalsh

Comment 5

[Oana Pop-Rus]

https://hg.mozilla.org/mozilla-central/rev/72f117346242