Re: Better error messages for corrupt databases

From: Shawn O. Pearce <spearce@spearce.org>
Date: Jan 12, 2007, 00:40 UTC
Message-ID: <20070112004044.GA23864@spearce.org>
In-Reply-To: <Pine.LNX.4.64.0701111400031.3594@woody.osdl.org>

Linus Torvalds <torvalds@osdl.org> wrote:

Show 6 quoted lines

> So this just makes "xmmap()" return NULL for a zero-sized object (which is 
> a valid thing pointer, exactly the same way "malloc()" can return NULL for 
> a zero-sized allocation). That fixes the first problem (but we could have 
> fixed it in the caller too - I don't personally much care whichever way it 
> goes, but maybe somebody should check that the NO_MMAP case does 
> something sane in this case too?).

All calls to perform any sort of mmap go through xmmap(). If NO_MMAP was defined at compile time than the mmap() call within xmmap() is redefined to invoke git_mmap() via a preprocessor define slightly earlier in git-compat-util.h.

So your patch will also automatically do the right thing in the NO_MMAP case.

BTW, I like your solution of just fixing it here in xmmap().  Good idea.

-- 
Shawn.