503166 - XPCStringConvert::ReadableToJSString shouldn't allocate for empty string

Status: RESOLVED FIXED

(Core :: XPConnect, defect)

Description

[Peter Van der Beken [:peterv]]

Attachment: v1

Every time XPCStringConvert::ReadableToJSString is passed an empty string, it'll try to get the nsStringBuffer without getting one, and it'll actually allocate a new buffer and JS string object. I think we should return a cached JSString in that case, and the JS engine seems to already have one in |cx->runtime->atomState.emptyAtom|. I've also made ReadableToJSString return a jsval, all callers want a jsval (and do STRING_TO_JSVAL), and we already have a jsval for emptyAtom anyway.

Comment 1

[Johnny Stenback (:jst)]

Comment on attachment 387521 [details] [diff] [review]
v1

r+sr=jst, but should we rename ReadableToJSString() to ReadableToJSVal() now that it returns a jsval, which actually may not be a string (if it returns JSVAL_NULL)?

Comment 2

[Peter Van der Beken [:peterv]]

http://hg.mozilla.org/mozilla-central/rev/790e9b3af32b