threads / patch / 24952

patchparse_object: pass on the original sha1, not the replaced one

Subject: [PATCH] parse_object: pass on the original sha1, not the replaced one

## tl;dr

3 messages between Sep 2, 2010 and Sep 3, 2010. Diffs are folded; open one to read it.

replies: 2people: 2as markdown or json

Christian Couder· Sep 2, 2010, 21:13 UTC · lore
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?= <pclouds@gmail.com>

Commit 0e87c36 (object: call "check_sha1_signature" with the replacement sha1) changed the first argument passed to parse_object_buffer() from "sha1" to "repl". With that change, the returned obj pointer has the replacement SHA1 in obj->sha1, not the original one.

But when using lookup_commit() and then parse_commit() on a commit, we get an object pointer with the original sha1, but the commit content comes from the replacement commit.

So the result we get from using parse_object() is different from the we get from using lookup_commit() followed by parse_commit().

It looks much simpler and safer to fix this inconsistency by passing "sha1" to parse_object_bufer() instead of "repl".

The commit comment should be used to tell the the replacement commit is replacing another commit and why. So it should be easy to see that we have a replacement commit instead of an original one.

And it is not a problem if the content of the commit is not consistent with the sha1 as cat-file piped to hash-object can be used to see the difference.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
Since no one resent the original patch with an improved commit
message, here is my try.
 object.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
Show changes to object.c +1 −1
diff --git a/object.c b/object.c
index 277b3dd..7adfda7 100644
--- a/object.c
+++ b/object.c
@@ -199,7 +199,7 @@ struct object *parse_object(const unsigned char *sha1)
 			return NULL;
 		}
 
-		obj = parse_object_buffer(repl, type, size, buffer, &eaten);
+		obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
 		if (!eaten)
 			free(buffer);
 		return obj;
-- 
1.7.2.2.417.g10a17
Nguyen Thai Ngoc Duy· Sep 2, 2010, 23:24 UTC · re: Christian Couder · lore

Re: [PATCH] parse_object: pass on the original sha1, not the replaced one

On Fri, Sep 3, 2010 at 7:13 AM, Christian Couder <chriscool@tuxfamily.org> wrote:

> Since no one resent the original patch with an improved commit
> message, here is my try.

My bad. I forgot something again. I will think of something to demonstrate this. By the way, it breaks t6050.14, bisect and replacements.

-- 
Duy
Christian Couder· Sep 3, 2010, 04:37 UTC · re: Nguyen Thai Ngoc Duy · lore

Re: [PATCH] parse_object: pass on the original sha1, not the replaced one

On Friday 03 September 2010 01:24:07 Nguyen Thai Ngoc Duy wrote:
Show 9 quoted lines
> On Fri, Sep 3, 2010 at 7:13 AM, Christian Couder
> 
> <chriscool@tuxfamily.org> wrote:
> > Since no one resent the original patch with an improved commit
> > message, here is my try.
> 
> My bad. I forgot something again. I will think of something to
> demonstrate this. By the way, it breaks t6050.14, bisect and
> replacements.
Ooops, yeah, I will have a look at this.

Thanks, Christian.

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