1674968 - UniqueJSONStrings copy constructor doesn't copy anything

Status: RESOLVED FIXED

(Core :: Gecko Profiler, defect, P2)

Description

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

At the start of the copy constructor, we look if there are elements in the current object under construction, instead of the given object to copy! The local default-constructed hash table will always be empty, so we won't copy anything.

The previous code before bug 1520104 did the right thing by counting elements in the given aOther.

The likely effect is that some strings coming from a JITFrameInfo would be lost, and references to these strings would likely point at different strings added during the profile serialization.
But nobody noticed 🤔

Comment 1

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Attachment: Bug 1674968 - UniqueJSONStrings unit tests - r?gregtatum

Comment 2

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Attachment: Bug 1674968 - Fix UniqueJSONStrings copy constructor, to actually copy from the source - r?gregtatum

Depends on D95832

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/4e9b6333fa61
UniqueJSONStrings unit tests - r=gregtatum
https://hg.mozilla.org/integration/autoland/rev/a3ebf62f6368
Fix UniqueJSONStrings copy constructor, to actually copy from the source - r=gregtatum

Comment 4

[Razvan Maries]

https://hg.mozilla.org/mozilla-central/rev/4e9b6333fa61
https://hg.mozilla.org/mozilla-central/rev/a3ebf62f6368