Re: [BUG] Cannot push some grafted branches

[Michael J Gruber <git@drmicha.warpmail.net>]

Junio C Hamano venit, vidit, dixit 21.12.2012 17:58:
> Michael J Gruber <git@drmicha.warpmail.net> writes:
> 
>> While replace refs are much more general than grafts, it seems the two
>> main uses are:
>>
>> - grafts (change the recorded parents for a commit)
>> - svn cleanup (convert tagging commits into tag objects)
>>
>> The latter one being quite a special case already.
>>
>> The script below has helped me move from grafts to replace objects.
>> While not being super clean, something like it may be fit for contrib.
>>
>> I think we ought to help John Doe get along with parents, while we can
>> safely leave most more advanced operations to people who know how to
>> edit a raw object file. Putting that facility into "git-commit" seems to
>> be too encouraging, though - people would use replace when they should
>> use amend or rebase-i. I'd prefer a special git-replace mode (be it
>> "--graft" or "--graft-commit") which does just what my script does. We
>> could add things like "--commit-tag" later, a full blown
>> "object-factory" seems like overkill.
>>
>> Michael
>>
>> --->%---
>>
>> #!/bin/sh
>>
>> die () {
>> 	echo "$@"
>> 	rm -f "$commitfile"
>>  	exit 1
>> }
>>
>> warn () {
>> 	echo "$@"
>> }
>>
>> test $# -gt 0 || die "Usage: $0 <commit> [<parent>]*"
>>
>> for commit
>> do
>> 	git rev-parse --verify -q "$commit" >/dev/null || die "Cannot parse
>> $commit."
>> 	test x$(git cat-file -t $commit) == "xcommit" || die "$commit is no
>> commit."
> 
> s/==/=/ or you have to say #!/bin/bash on the first line, I think.
> Appears multiple times throughout this script.
> 
> 
>> done
>>
>> commit="$1"
>> shift
>>
>> commitfile=$(mktemp)
>>
>> git cat-file commit "$commit" | while read a b
>> do
>> 	if test "$a" != "parent"
>> 	then
>> 		echo $a $b
> 
> You are losing information on non-header lines by reading without
> "-r" in the above, and also multi-line headers (e.g. mergetag),
> aren't you?
>

Oh yes, it has bashisms and imperfections. It's not a submitted patch,
not even RFC. It's meant to show the git-replace mode that many users
could benefit from: works for commits only and replaces the parent list,
but takes any rev arguments as the new parents, rather than forcing the
user to specify a full sha1.

>> 	fi
>> 	if test "$a" == "tree"
>> 	then
>> 		for parent
>> 		do
>> 			echo "parent $(git rev-parse $parent)"
>> 		done
>> 	fi
>> done >$commitfile
>> hash=$(git hash-object -t commit -w "$commitfile") || die "Cannot create
>> commit object."
>> git replace "$commit" $hash
>> rm -f $commitfile