# [PATCH] documentation: update git-submodule documentation

3 messages from 2022-11-03 to 2022-11-04. Participants: James via GitGitGadget, Ævar Arnfjörð Bjarmason, James McCandlish.
Thread: https://gitlist.dev/t/58740

## James via GitGitGadget, 2022-11-03 10:26

Subject: [PATCH] documentation: update git-submodule documentation
Message-ID: <pull.1401.git.1667471194097.gitgitgadget@gmail.com>
URL: https://gitlist.dev/e/pull.1401.git.1667471194097.gitgitgadget%40gmail.com

```
From: James <jdm12989@gmail.com>

Removes reference to custom code execution which is called out by
gitmodules as not allowed.

Signed-off-by: James <jdm12989@gmail.com>
---
    Update git-submodule.txt
    
    Remove info about custom commands being allowed in the submodule update
    command to align with the gitmodules docs which states "For security
    reasons, the !command form is not accepted here."

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1401%2FEnochPrime%2Fsubmodule-docs-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1401/EnochPrime/submodule-docs-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1401

 Documentation/git-submodule.txt | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 4d3ab6b9f92..b40ac72f753 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -163,12 +163,6 @@ checked out in the submodule.
 The following 'update' procedures are only available via the
 `submodule.<name>.update` configuration variable:
 
-	custom command;; arbitrary shell command that takes a single
-	    argument (the sha1 of the commit recorded in the
-	    superproject) is executed. When `submodule.<name>.update`
-	    is set to '!command', the remainder after the exclamation mark
-	    is the custom command.
-
 	none;; the submodule is not updated.
 
 If the submodule is not yet initialized, and you just want to use the

base-commit: c03801e19cb8ab36e9c0d17ff3d5e0c3b0f24193
-- 
gitgitgadget

```

## Ævar Arnfjörð Bjarmason, 2022-11-03 12:14

Subject: Re: [PATCH] documentation: update git-submodule documentation
Message-ID: <221103.86eduk1bcw.gmgdl@evledraar.gmail.com>
URL: https://gitlist.dev/e/221103.86eduk1bcw.gmgdl%40evledraar.gmail.com
In-Reply-To: <pull.1401.git.1667471194097.gitgitgadget@gmail.com>

```

On Thu, Nov 03 2022, James via GitGitGadget wrote:

> From: James <jdm12989@gmail.com>
>
> Removes reference to custom code execution which is called out by
> gitmodules as not allowed.
>
> Signed-off-by: James <jdm12989@gmail.com>
> ---
>     Update git-submodule.txt
>     
>     Remove info about custom commands being allowed in the submodule update
>     command to align with the gitmodules docs which states "For security
>     reasons, the !command form is not accepted here."
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1401%2FEnochPrime%2Fsubmodule-docs-v1
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1401/EnochPrime/submodule-docs-v1
> Pull-Request: https://github.com/gitgitgadget/git/pull/1401
>
>  Documentation/git-submodule.txt | 6 ------
>  1 file changed, 6 deletions(-)
>
> diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
> index 4d3ab6b9f92..b40ac72f753 100644
> --- a/Documentation/git-submodule.txt
> +++ b/Documentation/git-submodule.txt
> @@ -163,12 +163,6 @@ checked out in the submodule.
>  The following 'update' procedures are only available via the
>  `submodule.<name>.update` configuration variable:
>  
> -	custom command;; arbitrary shell command that takes a single
> -	    argument (the sha1 of the commit recorded in the
> -	    superproject) is executed. When `submodule.<name>.update`
> -	    is set to '!command', the remainder after the exclamation mark
> -	    is the custom command.
> -
>  	none;; the submodule is not updated.
>  
>  If the submodule is not yet initialized, and you just want to use the

Hrm?
	
	diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
	index a7683d35299..80e897d5f29 100644
	--- a/builtin/submodule--helper.c
	+++ b/builtin/submodule--helper.c
	@@ -2247,6 +2247,7 @@ static int run_update_command(const struct update_data *ud, int subforce)
	 	case SM_UPDATE_COMMAND:
	 		cp.use_shell = 1;
	 		strvec_push(&cp.args, ud->update_strategy.command);
	+		BUG("unused??");
	 		break;
	 	default:
	 		BUG("unexpected update strategy type: %d",
	
Will show you that this is used, i.e. this failure in
t7406-submodule-update.sh:
	
	[...]
	+ cd super
	+ git config submodule.submodule.update !git checkout
	+ cd super/submodule
	+ git reset --hard HEAD^
	HEAD is now at 0c90624 upstream
	+ cd super
	+ cd submodule
	+ compare_head
	+ git rev-list --max-count=1 main
	+ sha_main=0c90624ab7f1aaa301d3bb79f60dcfed1ec4897f
	+ git rev-list --max-count=1 HEAD
	+ sha_head=0c90624ab7f1aaa301d3bb79f60dcfed1ec4897f
	+ test 0c90624ab7f1aaa301d3bb79f60dcfed1ec4897f = 0c90624ab7f1aaa301d3bb79f60dcfed1ec4897f
	+ git submodule update submodule
	BUG: builtin/submodule--helper.c:2250: unused??
	Aborted

I think what you may be confused by is that this isn't allowed in the
in-tree .gitmodules file, and indeed you can see another BUG() in
determine_submodule_update_strategy() for a panic if we'd ever get as
far as reading "command" from there.

But that's not what this part of the docs dicsusses, as the paragraph
shown above the removed lines in the context notes.

```

## James McCandlish, 2022-11-04 11:25

Subject: Re: [PATCH] documentation: update git-submodule documentation
Message-ID: <CALwerKjpvH6V6httS9J5ws8=-n-ra7Lma4X4LHSSBLhVejp6bA@mail.gmail.com>
URL: https://gitlist.dev/e/CALwerKjpvH6V6httS9J5ws8%3D-n-ra7Lma4X4LHSSBLhVejp6bA%40mail.gmail.com
In-Reply-To: <221103.86eduk1bcw.gmgdl@evledraar.gmail.com>

```
Sorry about the confusion. Just so I'm 100% clear: the
`submodule.<name>.update` referencing a gitconfig and not gitmodules?


On Thu, Nov 3, 2022 at 8:17 AM Ævar Arnfjörð Bjarmason <avarab@gmail.com> wrote:
>
>
> On Thu, Nov 03 2022, James via GitGitGadget wrote:
>
> > From: James <jdm12989@gmail.com>
> >
> > Removes reference to custom code execution which is called out by
> > gitmodules as not allowed.
> >
> > Signed-off-by: James <jdm12989@gmail.com>
> > ---
> >     Update git-submodule.txt
> >
> >     Remove info about custom commands being allowed in the submodule update
> >     command to align with the gitmodules docs which states "For security
> >     reasons, the !command form is not accepted here."
> >
> > Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1401%2FEnochPrime%2Fsubmodule-docs-v1
> > Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1401/EnochPrime/submodule-docs-v1
> > Pull-Request: https://github.com/gitgitgadget/git/pull/1401
> >
> >  Documentation/git-submodule.txt | 6 ------
> >  1 file changed, 6 deletions(-)
> >
> > diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
> > index 4d3ab6b9f92..b40ac72f753 100644
> > --- a/Documentation/git-submodule.txt
> > +++ b/Documentation/git-submodule.txt
> > @@ -163,12 +163,6 @@ checked out in the submodule.
> >  The following 'update' procedures are only available via the
> >  `submodule.<name>.update` configuration variable:
> >
> > -     custom command;; arbitrary shell command that takes a single
> > -         argument (the sha1 of the commit recorded in the
> > -         superproject) is executed. When `submodule.<name>.update`
> > -         is set to '!command', the remainder after the exclamation mark
> > -         is the custom command.
> > -
> >       none;; the submodule is not updated.
> >
> >  If the submodule is not yet initialized, and you just want to use the
>
> Hrm?
>
>         diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
>         index a7683d35299..80e897d5f29 100644
>         --- a/builtin/submodule--helper.c
>         +++ b/builtin/submodule--helper.c
>         @@ -2247,6 +2247,7 @@ static int run_update_command(const struct update_data *ud, int subforce)
>                 case SM_UPDATE_COMMAND:
>                         cp.use_shell = 1;
>                         strvec_push(&cp.args, ud->update_strategy.command);
>         +               BUG("unused??");
>                         break;
>                 default:
>                         BUG("unexpected update strategy type: %d",
>
> Will show you that this is used, i.e. this failure in
> t7406-submodule-update.sh:
>
>         [...]
>         + cd super
>         + git config submodule.submodule.update !git checkout
>         + cd super/submodule
>         + git reset --hard HEAD^
>         HEAD is now at 0c90624 upstream
>         + cd super
>         + cd submodule
>         + compare_head
>         + git rev-list --max-count=1 main
>         + sha_main=0c90624ab7f1aaa301d3bb79f60dcfed1ec4897f
>         + git rev-list --max-count=1 HEAD
>         + sha_head=0c90624ab7f1aaa301d3bb79f60dcfed1ec4897f
>         + test 0c90624ab7f1aaa301d3bb79f60dcfed1ec4897f = 0c90624ab7f1aaa301d3bb79f60dcfed1ec4897f
>         + git submodule update submodule
>         BUG: builtin/submodule--helper.c:2250: unused??
>         Aborted
>
> I think what you may be confused by is that this isn't allowed in the
> in-tree .gitmodules file, and indeed you can see another BUG() in
> determine_submodule_update_strategy() for a panic if we'd ever get as
> far as reading "command" from there.
>
> But that's not what this part of the docs dicsusses, as the paragraph
> shown above the removed lines in the context notes.



-- 
James McCandlish

```
