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Re: [PATCH v4 3/4] git-submodule update: Add --branch option

From
Heiko Voigt <hvoigt@hvoigt.net>
Date
Nov 27, 2012, 18:51 UTC
Message-ID
<20121127185142.GB4185@book.hvoigt.net>
In-Reply-To
<95edff1c97c513c555652014f9c2bbf61c8e7560.1353962698.git.wking@tremily.us>
On Mon, Nov 26, 2012 at 04:00:18PM -0500, W. Trevor King wrote:
Show 76 quoted lines
> From: "W. Trevor King" <wking@tremily.us>
> 
> This allows users to checkout the current
> superproject-recorded-submodule-sha as a branch, avoiding the detached
> head state that the standard submodule update creates.  This may be
> useful for the existing --rebase/--merge workflows which already avoid
> detached heads.
> 
> It is also useful if you want easy tracking of upstream branches.  The
> particular upstream branch to be tracked is configured locally with
> .git/modules/<name>/config.  With the new option Ævar's suggested
> 
>   $ git submodule foreach 'git checkout $(git config --file $toplevel/.gitm
> odules submodule.$name.branch) && git pull'
> 
> reduces to a
> 
>   $ git submodule update --branch
> 
> after each supermodule .gitmodules edit, and a
> 
>   $ git submodule foreach 'git pull'
> 
> whenever you feel like updating the submodules.  Your still on you're
> own to commit (or not) the updated submodule hashes in the
> superproject's .gitmodules.
> 
> Signed-off-by: W. Trevor King <wking@tremily.us>
> ---
>  Documentation/git-submodule.txt | 20 +++++++++++------
>  git-submodule.sh                | 48 +++++++++++++++++++++++++++++----------
>  t/t7406-submodule-update.sh     | 50 ++++++++++++++++++++++++++++++++++++++++-
>  3 files changed, 98 insertions(+), 20 deletions(-)
> 
> diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
> index d0b4436..34392a1 100644
> --- a/Documentation/git-submodule.txt
> +++ b/Documentation/git-submodule.txt
> @@ -13,7 +13,7 @@ SYNOPSIS
>  	      [-f|--force] [--reference <repository>] [--] <repository> [<path>]
>  'git submodule' [--quiet] status [--cached] [--recursive] [--] [<path>...]
>  'git submodule' [--quiet] init [--] [<path>...]
> -'git submodule' [--quiet] update [--init] [-N|--no-fetch] [--rebase]
> +'git submodule' [--quiet] update [--init] [-N|--no-fetch] [--branch] [--rebase]
>  	      [--reference <repository>] [--merge] [--recursive] [--] [<path>...]
>  'git submodule' [--quiet] summary [--cached|--files] [(-n|--summary-limit) <n>]
>  	      [commit] [--] [<path>...]
> @@ -136,11 +136,11 @@ init::
>  
>  update::
>  	Update the registered submodules, i.e. clone missing submodules and
> -	checkout the commit specified in the index of the containing repository.
> -	This will make the submodules HEAD be detached unless `--rebase` or
> -	`--merge` is specified or the key `submodule.$name.update` is set to
> -	`rebase`, `merge` or `none`. `none` can be overridden by specifying
> -	`--checkout`.
> +	checkout the commit specified in the index of the containing
> +	repository.  This will make the submodules HEAD be detached unless
> +	`--branch`, `--rebase`, `--merge` is specified or the key
> +	`submodule.$name.update` is set to `branch`, `rebase`, `merge` or
> +	`none`. `none` can be overridden by specifying `--checkout`.
>  +
>  If the submodule is not yet initialized, and you just want to use the
>  setting as stored in .gitmodules, you can automatically initialize the
> @@ -207,7 +207,13 @@ OPTIONS
>  
>  -b::
>  --branch::
> -	Branch of repository to add as submodule.
> +	When used with the add command, gives the branch of repository to
> +	add as submodule.
> ++
> +When used with the update command, checks out a branch named
> +`submodule.<name>.branch` (as set by `--local-branch`) pointing at the
> +current HEAD SHA-1.  This is useful for commands like `update
> +--rebase` that do not work on detached heads.

Since you are reusing this option for update it further convinces me that reusing it for add makes sense and simplifies the logic for users.

I think an optional argument for --branch would be nice in the update case:

	$ git submodule update --branch=master

would then allow a user that has not configured anything (except the branch tracking info in the submodule of course) to pull all submodules master branches.

Show 10 quoted lines
> diff --git a/git-submodule.sh b/git-submodule.sh
> index c51b6ae..28eb4b1 100755
> --- a/git-submodule.sh
> +++ b/git-submodule.sh
> @@ -627,7 +631,7 @@ Maybe you want to use 'update --init'?")"
>  			die "$(eval_gettext "Unable to find current revision in submodule path '\$sm_path'")"
>  		fi
>  
> -		if test "$subsha1" != "$sha1" -o -n "$force"
> +		if test "$subsha1" != "$sha1" -o -n "$force" -o "$update_module" = "branch"

As said before I think separating your code from the current update logic will simplify the handling below.

Show 25 quoted lines
>  		then
>  			subforce=$force
>  			# If we don't already have a -f flag and the submodule has never been checked out
> @@ -650,16 +654,21 @@ Maybe you want to use 'update --init'?")"
>  			case ";$cloned_modules;" in
>  			*";$name;"*)
>  				# then there is no local change to integrate
> -				update_module= ;;
> +				case "$update_module" in
> +					rebase|merge)
> +						update_module=
> +						;;
> +				esac
> +				;;
>  			esac
>  
>  			must_die_on_failure=
>  			case "$update_module" in
>  			rebase)
>  				command="git rebase"
> -				die_msg="$(eval_gettext "Unable to rebase '\$sha1' in submodule path '\$sm_path'")"
> +				die_msg="$(eval_gettext "Unable to rebase '\$sha1' in submodule path '\$sm_path'")"	
>  				say_msg="$(eval_gettext "Submodule path '\$sm_path': rebased into '\$sha1'")"
> -				must_die_on_failure=yes
> +			must_die_on_failure=yes
Please always cleanup whitespace changes.
Show 15 quoted lines
>  				;;
>  			merge)
>  				command="git merge"
> @@ -674,15 +683,30 @@ Maybe you want to use 'update --init'?")"
>  				;;
>  			esac
>  
>  			then
> -				die_with_status 2 "$die_msg"
> -			else
> -				err="${err};$die_msg"
> -				continue
> +				if (clear_local_git_env; cd "$sm_path" &&
> +					git branch -f "$branch" "$sha1" &&
> +					git checkout "$branch")

You wrote in earlier emails that you wanted to protect the user from non-fastforward changes. So I would expect a

	$ git pull --ff-only
here and the setup of that in the initialization of the submodule.

BTW, I am more and more convinced that an automatically manufactured commit on update with --branch should be the default. What do other think? Sascha raised a concern that he would not want this, but as far as I understood he let the CI-server do that so I see no downside to natively adding that to git. People who want to manually craft those commits can still amend the generated commit. Since this is all about helping people keeping their submodules updated why not go the full way?

Cheers Heiko
Previous: W. Trevor KingNext: W. Trevor King
Message 31 of 49 in “git-submodule add: Add -r/--record option”
  1. 0/3 git-submodule add: Add -r/--record optionW. Trevor King, Nov 9, 2012
  2. 1/3 git-submodule add: Add -r/--record optionW. Trevor King, Nov 9, 2012
  3. Junio C HamanoNov 9, 2012
  4. Heiko VoigtNov 9, 2012
  5. W. Trevor KingNov 10, 2012
  6. W. Trevor KingNov 10, 2012
  7. Heiko VoigtNov 17, 2012
  8. Junio C HamanoNov 11, 2012
  9. W. Trevor KingNov 11, 2012
  10. Heiko VoigtNov 17, 2012
  11. W. Trevor KingNov 17, 2012
  12. Heiko VoigtNov 17, 2012
  13. W. Trevor KingNov 17, 2012
  14. Junio C HamanoNov 20, 2012
  15. W. Trevor KingNov 20, 2012
  16. Junio C HamanoNov 20, 2012
  17. W. Trevor KingNov 20, 2012
  18. Junio C HamanoNov 20, 2012
  19. Heiko VoigtNov 23, 2012
  20. Sascha CunzNov 23, 2012
  21. Heiko VoigtNov 23, 2012
  22. W. Trevor KingNov 23, 2012
  23. W. Trevor KingNov 23, 2012
  24. W. Trevor KingNov 23, 2012
  25. 0/4 git-submodule add: Add --local-branch optionW. Trevor King, Nov 26, 2012
  26. 1/4 git-submodule add: Add --local-branch optionW. Trevor King, Nov 26, 2012
  27. 2/4 git-submodule init: Record submodule.<name>.branch in repository config.W. Trevor King, Nov 26, 2012
  28. Jens LehmannNov 27, 2012
  29. W. Trevor KingNov 28, 2012
  30. 3/4 git-submodule update: Add --branch optionW. Trevor King, Nov 26, 2012
  31. Heiko VoigtNov 27, 2012
  32. W. Trevor KingNov 27, 2012
  33. [RFC] git-submodule update: Add --commit optionW. Trevor King, Nov 29, 2012
  34. W. Trevor KingNov 29, 2012
  35. W. Trevor KingNov 29, 2012
  36. 4/4 Hack fix for 'submodule update does not fetch already present commits'W. Trevor King, Nov 26, 2012
  37. W. Trevor KingNov 27, 2012
  38. Heiko VoigtNov 27, 2012
  39. W. Trevor KingNov 27, 2012
  40. Heiko VoigtNov 27, 2012
  41. W. Trevor KingNov 28, 2012
  42. Phil HordNov 29, 2012
  43. W. Trevor KingNov 27, 2012
  44. Heiko VoigtNov 27, 2012
  45. 2/3 git-submodule foreach: export .gitmodules settings as variablesW. Trevor King, Nov 9, 2012
  46. Heiko VoigtNov 9, 2012
  47. W. Trevor KingNov 10, 2012
  48. 3/3 git-submodule: Motivate --record with an example use caseW. Trevor King, Nov 9, 2012
  49. W. Trevor KingNov 10, 2012

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