Re: Bug in "git rev-parse --verify"

On 03/28/2013 02:48 PM, Junio C Hamano wrote:

I think it has always been about "is this well formed and we can turn it
into a raw 20-byte object name?" and never about"does it exist?"

That's surprising.  The man page says

    --verify
        The parameter given must be usable as a single, valid object name.
        Otherwise barf and abort.

"Valid", to me, implies that the parameter should be the name of an
actual object, and this also seems a more useful concept to me and more
consistent with the command's behavior when passed other arguments.


Is there a simple way to verify an object name more strictly and convert
it to an SHA1?  I can only think of solutions that require two commands,
like

    git cat-file -e $ARG && git rev-parse --verify $ARG

I suppose in most contexts where one wants to know whether an object
name is valid, one should also verify that the object has the type that
you expect:

    test X$(git cat-file -t $ARG) = Xcommit &&
        git rev-parse --verify $ARG

or (allowing tag dereferencing)

    git cat-file -e $ARG^{commit} &&
        git rev-parse --verify $ARG^{commit}

Michael

-- 
Michael Haggerty
mhagger@alum.mit.edu
http://softwareswirl.blogspot.com/

On Thu, Mar 28, 2013 at 04:34:19PM +0100, Michael Haggerty wrote:

Is there a simple way to verify an object name more strictly and convert
it to an SHA1?  I can only think of solutions that require two commands,
like

    git cat-file -e $ARG && git rev-parse --verify $ARG

Is the rev-parse line doing anything there? If $ARG does not resolve to
a sha1, then wouldn't cat-file have failed?

-Peff

On 03/28/2013 04:38 PM, Jeff King wrote:

On Thu, Mar 28, 2013 at 04:34:19PM +0100, Michael Haggerty wrote:

quoted

Is there a simple way to verify an object name more strictly and convert
it to an SHA1?  I can only think of solutions that require two commands,
like

    git cat-file -e $ARG && git rev-parse --verify $ARG

Is the rev-parse line doing anything there? If $ARG does not resolve to
a sha1, then wouldn't cat-file have failed?

It's outputting the SHA1, which cat-file seems incapable of providing in
a useful way.

Michael

-- 
Michael Haggerty
mhagger@alum.mit.edu
http://softwareswirl.blogspot.com/

On Thu, Mar 28, 2013 at 04:52:15PM +0100, Michael Haggerty wrote:

On 03/28/2013 04:38 PM, Jeff King wrote:

quoted

On Thu, Mar 28, 2013 at 04:34:19PM +0100, Michael Haggerty wrote:

quoted

Is there a simple way to verify an object name more strictly and convert
it to an SHA1?  I can only think of solutions that require two commands,
like

    git cat-file -e $ARG && git rev-parse --verify $ARG

Is the rev-parse line doing anything there? If $ARG does not resolve to
a sha1, then wouldn't cat-file have failed?

It's outputting the SHA1, which cat-file seems incapable of providing in
a useful way.

Ah, I see; I was looking too much at your example, and not thinking
about how you would want to use it in a script.

-Peff