310569 - 64-bit unsafe cast in nsMsgIncomingServer.cpp

Status: RESOLVED FIXED

(Thunderbird :: Build Config, defect)

Description

[Benjamin Smedberg]

nsMsgIncomingService casts directly from void* to int32, which break on x86_84.

Comment 1

[Benjamin Smedberg]

Attachment: use NS_PTR_TO_INT32

Comment 2

[Benjamin Smedberg]

This means we don't build on linux x86_64

Comment 3

[Scott MacGregor]

Comment on attachment 197990 [details] [diff] [review]
use NS_PTR_TO_INT32

much better

Comment 4

[Scott MacGregor]

*** Bug 310495 has been marked as a duplicate of this bug. ***

Comment 5

[Benjamin Smedberg]

Fixed, trunk and branch

Comment 6

[Ilya Konstantinov]

+  PRInt32 hashValue = NS_PTR_TO_INT32(m_downloadedHdrs.Get(&hashKey));
   if (hashValue)

mscott, why cast it to int in the first place?

Comment 7

[Ilya Konstantinov]

Benjamin, please address my comment. I think you are introducing a bug in this
patch.

Comment 8

[Benjamin Smedberg]

Ilya, the extra cast is probably not necessary, but it's not a bug.

Comment 9

[Ilya Konstantinov]

Why is it a bug, you ask? The comparison would fail for every non-0 64bit
pointer value which evaluates to '0' when cast to 32bit integer. This would be
wrong, as this code intends to check whether the value exists in the hashtable.

I understand the chances of this are slim, but still, it's simply not legal to
lose data here.

Comment 10

[Benjamin Smedberg]

It's not a pointer, it's a PRInt32 cast to a pointer. There can be no dataloss.