1759573 - Some spurious wasm:// source appear when opening the debugger on a page with asm.js

Status: NEW

(DevTools :: Debugger, defect, P3)

Description

[Alexandre Poirot [:ochameau]]

The test added in bug 1757937 highlights that the debugger shows a spurious source.
This source has a wasm:// URL and is sorted independently in the SourceTree.
This only happens when opening the page on an already loaded page and when this page has an ASM.js source.
When we try opening this source, we can't fetch its content and CodeMirror shows an error instead.

Comment 1

[Alexandre Poirot [:ochameau]]

The issue boils down to ThreadActor.addAllSources, which calls DebuggerAPI.findSources:
https://searchfox.org/mozilla-central/rev/b0779bcc485dc1c04334dfb9ea024cbfff7b961a/devtools/server/actors/thread.js#1458
And findSources should probably not return this buggy WASM source, whereas it returns a correct entry for the ASM.js source.

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:bomsy, could you have a look please?

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