409294 - valgrind: Conditional jump or move depends on uninitialised value(s) [@ nsProxyObjectCallInfo::CopyStrings]

Status: RESOLVED FIXED

(Core :: XPCOM, defect)

Description

[Mats Palmgren (inactive)]

valgrind: Conditional jump or move depends on uninitialised value(s) [@ nsProxyObjectCallInfo::CopyStrings]

The problem is the null-check here:
http://bonsai.mozilla.org/cvsblame.cgi?file=/mozilla/xpcom/proxy/src/nsProxyEvent.cpp&rev=1.98&root=/cvsroot&mark=229,231#219
because 'val.p' may not have been fully initialized if it's a shorter type:
http://bonsai.mozilla.org/cvsblame.cgi?file=/mozilla/xpcom/reflect/xptcall/public/xptcall.h&rev=1.31&root=/cvsroot&mark=126,128,157#118

There is no harm done in CopyStrings() because it checks the type_tag before
using the value. But it makes 'valgrind' noisy and suppressing this message
seems wrong, so I think it should be fixed.

Comment 1

[Mats Palmgren (inactive)]

Attachment: valgrind messages

Comment 2

[Mats Palmgren (inactive)]

Attachment: Like so?

Comment 3

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 294109 [details] [diff] [review]
Like so?

I can't review this; I'm no an XPCOM peer.  Please ask someone who is?

Comment 4

[Mats Palmgren (inactive)]

mozilla/xpcom/reflect/xptcall/public/xptcall.h 	1.32 

-> FIXED

Comment 6

[Jesse Ruderman]

Any reason to have "val.p = nsnull;" in both the if and else instead of above them?