56206 - superglobal-based JS embeddings burned by fun_resolve

Status: VERIFIED FIXED

(Core :: JavaScript Engine, defect, P1)

Description

[Brendan Eich [:brendan]]

because fun_resolve uses js_NewObject(cx, &js_ObjectClass, proto, NULL) where
proto is the "parent proto" or superglobal's function.prototype property value,
and NULL as the 4th arg causes js_NewObject to default the new object's parent
from proto.constructor.__parent__ (which is the superglobal).

You end up with cloned function objects have .prototypes that are proto-clones
of the original function object's .prototype, but the child .prototypes have as
their __parent__ the superglobal!  Bad parenting here can lead to other bugs and
confusion later.

Patch coming up.

/be

Comment 1

[Brendan Eich [:brendan]]

Attachment: proposed fix

Comment 2

[Brendan Eich [:brendan]]

I can't write today to save my ass.  Sorry for the mangled syntax there!  Gimme
r= and a= love, ok?

/be

Comment 3

[Brendan Eich [:brendan]]

Better patch coming up.  No need for separate JS_SetPrototype given non-null
parent arg to js_NewObject.

/be

Comment 4

[Brendan Eich [:brendan]]

Attachment: better proposed fix

Comment 5

[Brendan Eich [:brendan]]

Anyone have time to study this patch?  Ask me questions!

/be

Comment 6

[Brendan Eich [:brendan]]

Adding r= buddies, soliciting r= and a=.

/be

Comment 7

[Brendan Eich [:brendan]]

High priority for me, want to get this patch in soon.

/be

Comment 8

[Brendan Eich [:brendan]]

Meow?

/be

Comment 9

[Mike McCabe]

Wow, I want to use 'ad perniciem' in my comments.

Is there an essay somewhere on just how superglobals work?

r=mccabe.

Comment 10

[Brendan Eich [:brendan]]

Superglobals are mainly documented by newsgroup postings, such as
http://x53.deja.com/%5BST_rn=ps%5D/getdoc.xp?AN=541478652&CONTEXT=975966602.402128927&hitnum=8

(That flagrant latinism was from shaver. ;-)  Thanks for the r= -- on to jband.

/be

Comment 11

[John Bandhauer]

sr=jband

Comment 12

[Brendan Eich [:brendan]]

Fixed.

/be

Comment 13

[Phil Schwartau]

Marking Verified -