Subject: Re: [PATCH] git-am: make a config setting for --keep-non-patch switch

From: Paul Gortmaker <[email-masked]>
Date: Wed, 1 Aug 2012 15:56:35 -0400

On 12-08-01 02:48 PM, Junio C Hamano wrote:
> Paul Gortmaker <[email-masked]> writes:
> 
>> In order to make a commit be invariant (excluding ID) over
>> a format-patch and subsequent am cycle, one needs to use
>> the '--keep-non-patch' so that commits like:
>>
>> 	[PATCH] [i386] fix foo bar arch/x86/mm
>>
>> only lose the [PATCH] and not the [i386] part.  Since it
>> is a common desire (e.g. linux kernel stable trees) to have
>> the subjects remain invariant during a backport, there is
>> a genuine need for making this the default behaviour from
>> a config file, versus specifying it in scripts and on the
>> command line each time.
>>
>> Signed-off-by: Paul Gortmaker <[email-masked]>
>> ---
>>
>> See http://lkml.indiana.edu/hypermail/linux/kernel/1203.1/01817.html
>> for additional background; stable maintainers using it etc.
> 
> That's a blast from the past; it would have been so much nicer
> if the patch came earlier ;-)

I just happened to "rediscover" the issue yesterday when backporting
a patch that had [S390] in it to linux-2.6.34 -- went looking for
any possible previous reports and found the above thread.  So the
timing was largely out of my control.  :)

> 
> The patch looks from sane; we may want to have a test in t4150, just like
> we have tests for am.keepcr in t4253.  We have plenty of time as we
> are in feature freeze right now.

I'll take a look at the test cases, and resend once 1.7.12 is done.

Paul.
--

> 
> Thanks.
> 
>>
>>  Documentation/config.txt               | 9 +++++++++
>>  Documentation/git-am.txt               | 4 ++++
>>  contrib/completion/git-completion.bash | 1 +
>>  git-am.sh                              | 8 ++++++++
>>  4 files changed, 22 insertions(+)
>>
>> diff --git a/Documentation/config.txt b/Documentation/config.txt
>> index a95e5a4..47aded5 100644
>> --- a/Documentation/config.txt
>> +++ b/Documentation/config.txt
>> @@ -655,6 +655,15 @@ am.keepcr::
>>  	by giving '--no-keep-cr' from the command line.
>>  	See linkgit:git-am[1], linkgit:git-mailsplit[1].
>>  
>> +am.keepnonpatch::
>> +	Normally git-mailinfo strips from the Subject line, all leading
>> +	strings bracketed with [ and ] pairs.  If this setting is true,
>> +	git-am will call git-mailinfo with the parameter '-b' so that only
>> +	the pairs whose bracketed string contains the word "PATCH" are
>> +	stripped.  Can be overridden by giving ' '--no-keep-non-patch'
>> +	from the command line.
>> +	See linkgit:git-am[1], linkgit:git-mailinfo[1].
>> +
>>  apply.ignorewhitespace::
>>  	When set to 'change', tells 'git apply' to ignore changes in
>>  	whitespace, in the same way as the '--ignore-space-change'
>> diff --git a/Documentation/git-am.txt b/Documentation/git-am.txt
>> index 19d57a8..790efdb 100644
>> --- a/Documentation/git-am.txt
>> +++ b/Documentation/git-am.txt
>> @@ -41,7 +41,11 @@ OPTIONS
>>  	Pass `-k` flag to 'git mailinfo' (see linkgit:git-mailinfo[1]).
>>  
>>  --keep-non-patch::
>> +--no-keep-non-patch::
>>  	Pass `-b` flag to 'git mailinfo' (see linkgit:git-mailinfo[1]).
>> +	The `am.keepnonpatch` configuration variable can be used to specify
>> +	the default behaviour.  The `--no-keep-non-patch` is useful to
>> +	override any `am.keepnonpatch` setting.
>>  
>>  --keep-cr::
>>  --no-keep-cr::
>> diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
>> index ffedce7..04339df 100644
>> --- a/contrib/completion/git-completion.bash
>> +++ b/contrib/completion/git-completion.bash
>> @@ -1758,6 +1758,7 @@ _git_config ()
>>  		advice.statusHints
>>  		alias.
>>  		am.keepcr
>> +		am.keepnonpatch
>>  		apply.ignorewhitespace
>>  		apply.whitespace
>>  		branch.autosetupmerge
>> diff --git a/git-am.sh b/git-am.sh
>> index c02e62d..9f6adbf 100755
>> --- a/git-am.sh
>> +++ b/git-am.sh
>> @@ -16,6 +16,7 @@ s,signoff       add a Signed-off-by line to the commit message
>>  u,utf8          recode into utf8 (default)
>>  k,keep          pass -k flag to git-mailinfo
>>  keep-non-patch  pass -b flag to git-mailinfo
>> +no-keep-non-patch do not pass -b flag to git-mailsplit, independent of am.keepnonpatch
>>  keep-cr         pass --keep-cr flag to git-mailsplit for mbox format
>>  no-keep-cr      do not pass --keep-cr flag to git-mailsplit independent of am.keepcr
>>  c,scissors      strip everything before a scissors line
>> @@ -381,6 +382,11 @@ then
>>      keepcr=t
>>  fi
>>  
>> +if test "$(git config --bool --get am.keepnonpatch)" = true
>> +then
>> +    keep=b
>> +fi
>> +
>>  while test $# != 0
>>  do
>>  	case "$1" in
>> @@ -402,6 +408,8 @@ do
>>  		keep=t ;;
>>  	--keep-non-patch)
>>  		keep=b ;;
>> +	--no-keep-non-patch)
>> +		keep= ;;
>>  	-c|--scissors)
>>  		scissors=t ;;
>>  	--no-scissors)