From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Sat, 08 Oct 2005 19:04:44 GMT
Subject: Re: First cut at git port to Cygwin
Message-ID: <Pine.LNX.4.63.0510082100020.26626@wbgn013.biozentrum.uni-wuerzburg.de>
In-Reply-To: <7vr7avrgr2.fsf@assigned-by-dhcp.cox.net>

Hi,

On Sat, 8 Oct 2005, Junio C Hamano wrote:

> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
> 
> > Am I missing something? I don't see where the changes are written back to 
> > the fd. After all, mmap() is called with PROT_WRITE...
> 
> PROT_WRITE is true, but we do MAP_PRIVATE, and if I recall
> correctly we do not write file via mmap -- at least we do not
> intend to.

Ahh! Reading the man page helps!

> Yes.  It might have been overkill that you supported writing
> changes back, though.

Sure. Something like this?

diff --git a/compat/mmap.c b/compat/mmap.c
index fca6321..fda39fc 100644
--- a/compat/mmap.c
+++ b/compat/mmap.c
@@ -49,7 +49,7 @@ void *gitfakemmap(void *start, size_t le
 		n += count;
 	}
 
-	if(prot & PROT_WRITE) {
+	if((prot & PROT_WRITE) && !(flags & MAP_PRIVATE)) {
 		fakemmapwritable *next = xmalloc(sizeof(fakemmapwritable));
 		next->start = start;
 		next->length = length;