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[1/1] config: support a default remote tracking setup upon branch creation

Message ID 20210729020125.746206-2-mathstuf@gmail.com (mailing list archive)
State New
Headers show
Series [1/1] config: support a default remote tracking setup upon branch creation | expand

Commit Message

Ben Boeckel July 29, 2021, 2:01 a.m. UTC
The `branch.autoSetupMerge` works well today for setting up tracking a
local branch, but there is no easy mechanism to automatically set up a
remote tracking situation for workflows which use a single set of
branches for integration without specifying `--track` to every branch
creation command or branching directly from the remote ref. This patch
adds the following configuration values:

  - `branch.defaultRemote`: initializes `branch.<name>.remote` if not
    otherwise given;
  - `branch.defaultMerge`: initializes `branch.<name>.merge` if not
    otherwise given.

These effectively make branch creation commands such as `git branch`,
`git switch`, and `git checkout -b` have an implicit `-t
${branch.defaultRemote}/${branch.defaultMerge}` argument and is
equivalent to doing:

    $ git branch new-topic      # or another branch creation command
    $ git branch --set-upstream-to=${branch.defaultRemote}/${branch.defaultMerge} new-topic

In a fork-based workflow where contributions to the main project flow in
through forks of the main repository rather than pushing directly to it
(not uncommon of forge-hosted projects), the following setup may be
used:

    $ git config remote.pushDefault myfork    # push to `myfork` by default
    $ git config push.default simple          # the default
    $ git config branch.autoSetupMerge always # always setup tracking
    $ git config branch.defaultRemote origin  # track from `origin`
    $ git config branch.defaultMerge main     # track the `main` branch

With this setup, branches will automatically be set up to track
`origin/main` while being pushed to `myfork` by default. Some tools
(at least Vim's fugitive plugin) will show the commit differences
between both the tracking branch and the default push target. This
allows such tools to easily show "what needs to be merged?", "what has
happened on the target branch since this topic has been created?", and
"what is my status against my fork's current status?" at a glance.

Additionally, with the `extensions.worktreeConfig` setting, when a
separate work tree which is used for changes against a different branch
(e.g., a branch tracking a prior release), the `branch.defaultMerge`
setting may be changed independently, e.g., to `maint`.

Signed-off-by: Ben Boeckel <mathstuf@gmail.com>
---
 Documentation/config/branch.txt | 14 ++++++++++++
 branch.c                        | 22 ++++++++++---------
 branch.h                        |  2 ++
 config.c                        | 10 +++++++++
 environment.c                   |  2 ++
 t/t3200-branch.sh               | 39 +++++++++++++++++++++++++++++++++
 6 files changed, 79 insertions(+), 10 deletions(-)

Comments

Philippe Blain July 30, 2021, 1:35 p.m. UTC | #1
Le 2021-07-28 à 22:01, Ben Boeckel a écrit :
> The `branch.autoSetupMerge` works well today for setting up tracking a
> local branch, but there is no easy mechanism to automatically set up a
> remote tracking situation for workflows which use a single set of
> branches for integration without specifying `--track` to every branch
> creation command or branching directly from the remote ref. This patch
> adds the following configuration values:
> 
>    - `branch.defaultRemote`: initializes `branch.<name>.remote` if not
>      otherwise given;
>    - `branch.defaultMerge`: initializes `branch.<name>.merge` if not
>      otherwise given.
> 
> These effectively make branch creation commands such as `git branch`,
> `git switch`, and `git checkout -b` have an implicit `-t
> ${branch.defaultRemote}/${branch.defaultMerge}` argument and is
> equivalent to doing:
> 
>      $ git branch new-topic      # or another branch creation command
>      $ git branch --set-upstream-to=${branch.defaultRemote}/${branch.defaultMerge} new-topic
> 
> In a fork-based workflow where contributions to the main project flow in
> through forks of the main repository rather than pushing directly to it
> (not uncommon of forge-hosted projects), the following setup may be
> used:
> 
>      $ git config remote.pushDefault myfork    # push to `myfork` by default
>      $ git config push.default simple          # the default
>      $ git config branch.autoSetupMerge always # always setup tracking

OK, so if I understand correctly this exisiting setting has to be changed
to 'always' for the new settings you are adding to take effect, right ?
I think this does make sense, reading the description of 'branch.autoSetupMerge',
but maybe it should be spelled explicitely in the text of the commit message,
and not just mentioned here in this terminal session excerpt.

>      $ git config branch.defaultRemote origin  # track from `origin`
>      $ git config branch.defaultMerge main     # track the `main` branch

Small nit: maybe I would invert these two, so it can read:

       $ git config branch.defaultMerge main     # track the `main` branch ...
       $ git config branch.defaultRemote origin  # ... from `origin`
> 
> With this setup, branches will automatically be set up to track
> `origin/main` while being pushed to `myfork` by default. Some tools
> (at least Vim's fugitive plugin) will show the commit differences
> between both the tracking branch and the default push target. This
> allows such tools to easily show "what needs to be merged?", "what has
> happened on the target branch since this topic has been created?", and
> "what is my status against my fork's current status?" at a glance.
> 
> Additionally, with the `extensions.worktreeConfig` setting, when a
> separate work tree which is used for changes against a different branch
> (e.g., a branch tracking a prior release), the `branch.defaultMerge`
> setting may be changed independently, e.g., to `maint`.

This last paragraph is not explicitely needed, as nothing relating to
'extensions.worktreeConfig' is changed here right ? It's just the normal
way that this setting works.

> 
> Signed-off-by: Ben Boeckel <mathstuf@gmail.com>
> ---
>   Documentation/config/branch.txt | 14 ++++++++++++
>   branch.c                        | 22 ++++++++++---------
>   branch.h                        |  2 ++
>   config.c                        | 10 +++++++++
>   environment.c                   |  2 ++
>   t/t3200-branch.sh               | 39 +++++++++++++++++++++++++++++++++
>   6 files changed, 79 insertions(+), 10 deletions(-)
> 
> diff --git a/Documentation/config/branch.txt b/Documentation/config/branch.txt
> index cc5f3249fc..ab5cd2c1ed 100644
> --- a/Documentation/config/branch.txt
> +++ b/Documentation/config/branch.txt
> @@ -1,3 +1,17 @@
> +branch.defaultRemote::
> +	Tells 'git branch', 'git switch' and 'git checkout' to set up new branches
> +	so that it will track a branch on the specified remote. This can be
> +	used, in conjunction with `branch.defaultMerge`, in projects where
> +	branches tend to target a single branch. This will be used to
> +	initialize the "branch.<name>.remote" setting.
> +
> +branch.defaultMerge::
> +	Tells 'git branch', 'git switch' and 'git checkout' to set up new branches
> +	so that it will track a branch with this name. This can be used, in
> +	conjunction with `branch.defaultRemote` in projects where branches tend
> +	to target a single branch. This will be used to initialize the
> +	"branch.<name>.merge" setting.

For the two setting above, if 'branch.autoSetupMerge' must be set to 'always' for
the settings to work, I think it should be explicitely mentioned.

> +
>   branch.autoSetupMerge::
>   	Tells 'git branch', 'git switch' and 'git checkout' to set up new branches
>   	so that linkgit:git-pull[1] will appropriately merge from the
> diff --git a/branch.c b/branch.c
> index 7a88a4861e..097d5af647 100644
> --- a/branch.c
> +++ b/branch.c
> @@ -60,6 +60,8 @@ int install_branch_config(int flag, const char *local, const char *origin, const
>   	const char *shortname = NULL;
>   	struct strbuf key = STRBUF_INIT;
>   	int rebasing = should_setup_rebase(origin);
> +	const char *actual_origin = origin ? origin : git_branch_remote;
> +	const char *actual_remote = remote ? remote : git_branch_merge;
>   
>   	if (skip_prefix(remote, "refs/heads/", &shortname)
>   	    && !strcmp(local, shortname)
> @@ -70,12 +72,12 @@ int install_branch_config(int flag, const char *local, const char *origin, const
>   	}
>   
>   	strbuf_addf(&key, "branch.%s.remote", local);
> -	if (git_config_set_gently(key.buf, origin ? origin : ".") < 0)
> +	if (git_config_set_gently(key.buf, actual_origin ? actual_origin : ".") < 0)
>   		goto out_err;
>   
>   	strbuf_reset(&key);
>   	strbuf_addf(&key, "branch.%s.merge", local);
> -	if (git_config_set_gently(key.buf, remote) < 0)
> +	if (git_config_set_gently(key.buf, actual_remote) < 0)
>   		goto out_err;
>   
>   	if (rebasing) {
> @@ -88,27 +90,27 @@ int install_branch_config(int flag, const char *local, const char *origin, const
>   
>   	if (flag & BRANCH_CONFIG_VERBOSE) {
>   		if (shortname) {
> -			if (origin)
> +			if (actual_origin)
>   				printf_ln(rebasing ?
>   					  _("Branch '%s' set up to track remote branch '%s' from '%s' by rebasing.") :
>   					  _("Branch '%s' set up to track remote branch '%s' from '%s'."),
> -					  local, shortname, origin);
> +					  local, shortname, actual_origin);
>   			else
>   				printf_ln(rebasing ?
>   					  _("Branch '%s' set up to track local branch '%s' by rebasing.") :
>   					  _("Branch '%s' set up to track local branch '%s'."),
>   					  local, shortname);
>   		} else {
> -			if (origin)
> +			if (actual_origin)
>   				printf_ln(rebasing ?
>   					  _("Branch '%s' set up to track remote ref '%s' by rebasing.") :
>   					  _("Branch '%s' set up to track remote ref '%s'."),
> -					  local, remote);
> +					  local, actual_remote);
>   			else
>   				printf_ln(rebasing ?
>   					  _("Branch '%s' set up to track local ref '%s' by rebasing.") :
>   					  _("Branch '%s' set up to track local ref '%s'."),
> -					  local, remote);
> +					  local, actual_remote);
>   		}
>   	}
>   
> @@ -119,9 +121,9 @@ int install_branch_config(int flag, const char *local, const char *origin, const
>   	error(_("Unable to write upstream branch configuration"));
>   
>   	advise(_(tracking_advice),
> -	       origin ? origin : "",
> -	       origin ? "/" : "",
> -	       shortname ? shortname : remote);
> +	       actual_origin ? actual_origin : "",
> +	       actual_origin ? "/" : "",
> +	       shortname ? shortname : actual_remote);
>   
>   	return -1;
>   }
> diff --git a/branch.h b/branch.h
> index df0be61506..7d7990dda7 100644
> --- a/branch.h
> +++ b/branch.h
> @@ -14,6 +14,8 @@ enum branch_track {
>   };
>   
>   extern enum branch_track git_branch_track;
> +extern const char* git_branch_remote;
> +extern const char* git_branch_merge;
>   
>   /* Functions for acting on the information about branches. */
>   
> diff --git a/config.c b/config.c
> index f33abeab85..a46c5a43a1 100644
> --- a/config.c
> +++ b/config.c
> @@ -1599,6 +1599,16 @@ static int git_default_branch_config(const char *var, const char *value)
>   			return error(_("malformed value for %s"), var);
>   		return 0;
>   	}
> +	if (!strcmp(var, "branch.defaultremote")) {
> +		if (!value)
> +			return config_error_nonbool(var);
> +		return git_config_string(&git_branch_remote, var, value);
> +	}
> +	if (!strcmp(var, "branch.defaultmerge")) {
> +		if (!value)
> +			return config_error_nonbool(var);
> +		return git_config_string(&git_branch_merge, var, value);
> +	}
>   
>   	/* Add other config variables here and to Documentation/config.txt. */
>   	return 0;
> diff --git a/environment.c b/environment.c
> index 2f27008424..d550deabbd 100644
> --- a/environment.c
> +++ b/environment.c
> @@ -60,6 +60,8 @@ int global_conv_flags_eol = CONV_EOL_RNDTRP_WARN;
>   char *check_roundtrip_encoding = "SHIFT-JIS";
>   unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
>   enum branch_track git_branch_track = BRANCH_TRACK_REMOTE;
> +const char* git_branch_remote = NULL;
> +const char* git_branch_merge = NULL;

Can the new settings be implemented without adding more global variables ?
I think we are trying to move away from these. Apart from that the code
looks OK to me.

>   enum rebase_setup_type autorebase = AUTOREBASE_NEVER;
>   enum push_default_type push_default = PUSH_DEFAULT_UNSPECIFIED;
>   #ifndef OBJECT_CREATION_MODE
> diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
> index cc4b10236e..82137e8451 100755
> --- a/t/t3200-branch.sh
> +++ b/t/t3200-branch.sh
> @@ -797,6 +797,45 @@ test_expect_success 'test tracking setup via --track but deeper' '
>   	test "$(git config branch.my7.merge)" = refs/heads/o/o
>   '
>   
> +test_expect_success 'test tracking setup via branch.default* and --track' '
> +	git config branch.autosetupmerge always &&

You can use 'test_config branch.autosetupmerge always' so that the
config is only active for the duration of the 'test_expect_success' block
(see t/test-lib-functions.sh).

> +	git config branch.defaultremote local &&
> +	git config branch.defaultmerge main &&
> +	git config remote.local.url . &&
> +	git config remote.local.fetch refs/heads/*:refs/remotes/local/* &&
> +	(git show-ref -q refs/remotes/local/main || git fetch local) &&
> +	git branch --track other/foo my2 &&
> +	git config branch.autosetupmerge false &&
> +	test "$(git config branch.my2.remote)" = other &&

Here and for the following line you can use 'test_cmp_config'.

> +	test "$(git config branch.my2.merge)" = refs/heads/foo
> +'

This tests checks that an explicit '--track' argument overrides the new configs.
I would name it something like "'--track overrides 'branch.default{merge,remote}'"
or something like this. I would also add another test before this one that just
checks that the new settings by themselves work as expected;
i.e. a simple 'git checkout -b' and verifying that the
tracking info is correctly configured according to 'branch.default{merge,remote}'.

> +
> +test_expect_success 'test tracking setup via branch.default* and --no-track' '
> +	git config branch.autosetupmerge always &&
> +	git config branch.defaultremote local &&
> +	git config branch.defaultmerge main &&
> +	git config remote.local.url . &&
> +	git config remote.local.fetch refs/heads/*:refs/remotes/local/* &&
> +	(git show-ref -q refs/remotes/local/main || git fetch local) &&
> +	git branch --no-track my2 &&
> +	git config branch.autosetupmerge false &&
> +	! test "$(git config branch.my2.remote)" = local &&
> +	! test "$(git config branch.my2.merge)" = refs/heads/main

Here you expect the configs to be absent, so for more clarity you could
do

     git config branch.my2.remote >remote &&
     test_must_be_empty remote

and the same for merge.

> +'
> +
> +test_expect_success 'test tracking setup via branch.default*' '
> +	git config branch.autosetupmerge always &&
> +	git config branch.defaultremote local &&
> +	git config branch.defaultmerge main &&
> +	git config remote.local.url . &&
> +	git config remote.local.fetch refs/heads/*:refs/remotes/local/* &&
> +	(git show-ref -q refs/remotes/local/main || git fetch local) &&
> +	git branch my2 &&
> +	git config branch.autosetupmerge false &&
> +	test "$(git config branch.my2.remote)" = local &&
> +	test "$(git config branch.my2.merge)" = refs/heads/main
> +'
> +
>   test_expect_success 'test deleting branch deletes branch config' '
>   	git branch -d my7 &&
>   	test -z "$(git config branch.my7.remote)" &&
> 

Oh, so here is the 'just test the new settings' test. Let's move that
one to be before the two others.

Another test that could be added is one that does not change
'branch.autosetupmerge' but sets the new configs, and checks that the
tracking info is *not* set.

Cheers,

Philippe.
Ben Boeckel July 30, 2021, 2:07 p.m. UTC | #2
On Fri, Jul 30, 2021 at 09:35:49 -0400, Philippe Blain wrote:
> Le 2021-07-28 à 22:01, Ben Boeckel a écrit :
> >      $ git config remote.pushDefault myfork    # push to `myfork` by default
> >      $ git config push.default simple          # the default
> >      $ git config branch.autoSetupMerge always # always setup tracking
> 
> OK, so if I understand correctly this exisiting setting has to be changed
> to 'always' for the new settings you are adding to take effect, right ?
> I think this does make sense, reading the description of 'branch.autoSetupMerge',
> but maybe it should be spelled explicitely in the text of the commit message,
> and not just mentioned here in this terminal session excerpt.

Good point. I'll add it.

> >      $ git config branch.defaultRemote origin  # track from `origin`
> >      $ git config branch.defaultMerge main     # track the `main` branch
> 
> Small nit: maybe I would invert these two, so it can read:
> 
>        $ git config branch.defaultMerge main     # track the `main` branch ...
>        $ git config branch.defaultRemote origin  # ... from `origin`

Agreed.

> > Additionally, with the `extensions.worktreeConfig` setting, when a
> > separate work tree which is used for changes against a different branch
> > (e.g., a branch tracking a prior release), the `branch.defaultMerge`
> > setting may be changed independently, e.g., to `maint`.
> 
> This last paragraph is not explicitely needed, as nothing relating to
> 'extensions.worktreeConfig' is changed here right ? It's just the normal
> way that this setting works.

Yes. I'll mention more explicitly that this is the reason for preserving
split settings (rather than a single `branch.defaultTrack = origin/main`
setting that I had thought about until I saw the `--worktree` flag to
`git config` and was intrigued).

> > +branch.defaultRemote::
> > +	Tells 'git branch', 'git switch' and 'git checkout' to set up new branches
> > +	so that it will track a branch on the specified remote. This can be
> > +	used, in conjunction with `branch.defaultMerge`, in projects where
> > +	branches tend to target a single branch. This will be used to
> > +	initialize the "branch.<name>.remote" setting.
> > +
> > +branch.defaultMerge::
> > +	Tells 'git branch', 'git switch' and 'git checkout' to set up new branches
> > +	so that it will track a branch with this name. This can be used, in
> > +	conjunction with `branch.defaultRemote` in projects where branches tend
> > +	to target a single branch. This will be used to initialize the
> > +	"branch.<name>.merge" setting.
> 
> For the two setting above, if 'branch.autoSetupMerge' must be set to 'always' for
> the settings to work, I think it should be explicitely mentioned.

Will update.

> > diff --git a/environment.c b/environment.c
> > index 2f27008424..d550deabbd 100644
> > --- a/environment.c
> > +++ b/environment.c
> > @@ -60,6 +60,8 @@ int global_conv_flags_eol = CONV_EOL_RNDTRP_WARN;
> >   char *check_roundtrip_encoding = "SHIFT-JIS";
> >   unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
> >   enum branch_track git_branch_track = BRANCH_TRACK_REMOTE;
> > +const char* git_branch_remote = NULL;
> > +const char* git_branch_merge = NULL;
> 
> Can the new settings be implemented without adding more global variables ?
> I think we are trying to move away from these. Apart from that the code
> looks OK to me.

I'm all for that, but didn't see guidance on where such things should be
stored. There's not a "context" object passed around, but I guess
stuffing it into `repository` is fine? This also gives a nice place to
free them rather than just leaking them too.

Alas, after some cursory investigation,
`config.c@@git_default_branch_config` does not have access to "the
repository" and the `cb` in `git_default_config` seems to be ~always be
`NULL`. So maybe that will have to wait for further refactoring of the
configuration tracking logic?

> > diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
> > index cc4b10236e..82137e8451 100755
> > --- a/t/t3200-branch.sh
> > +++ b/t/t3200-branch.sh
> > @@ -797,6 +797,45 @@ test_expect_success 'test tracking setup via --track but deeper' '
> >   	test "$(git config branch.my7.merge)" = refs/heads/o/o
> >   '
> >   
> > +test_expect_success 'test tracking setup via branch.default* and --track' '
> > +	git config branch.autosetupmerge always &&
> 
> You can use 'test_config branch.autosetupmerge always' so that the
> config is only active for the duration of the 'test_expect_success' block
> (see t/test-lib-functions.sh).

Nifty.

> > +	git config branch.defaultremote local &&
> > +	git config branch.defaultmerge main &&
> > +	git config remote.local.url . &&
> > +	git config remote.local.fetch refs/heads/*:refs/remotes/local/* &&
> > +	(git show-ref -q refs/remotes/local/main || git fetch local) &&
> > +	git branch --track other/foo my2 &&
> > +	git config branch.autosetupmerge false &&
> > +	test "$(git config branch.my2.remote)" = other &&
> 
> Here and for the following line you can use 'test_cmp_config'.
> 
> > +	test "$(git config branch.my2.merge)" = refs/heads/foo
> > +'
> 
> This tests checks that an explicit '--track' argument overrides the new configs.
> I would name it something like "'--track overrides 'branch.default{merge,remote}'"
> or something like this. I would also add another test before this one that just
> checks that the new settings by themselves work as expected;
> i.e. a simple 'git checkout -b' and verifying that the
> tracking info is correctly configured according to 'branch.default{merge,remote}'.
> 
> > +
> > +test_expect_success 'test tracking setup via branch.default* and --no-track' '
> > +	git config branch.autosetupmerge always &&
> > +	git config branch.defaultremote local &&
> > +	git config branch.defaultmerge main &&
> > +	git config remote.local.url . &&
> > +	git config remote.local.fetch refs/heads/*:refs/remotes/local/* &&
> > +	(git show-ref -q refs/remotes/local/main || git fetch local) &&
> > +	git branch --no-track my2 &&
> > +	git config branch.autosetupmerge false &&
> > +	! test "$(git config branch.my2.remote)" = local &&
> > +	! test "$(git config branch.my2.merge)" = refs/heads/main
> 
> Here you expect the configs to be absent, so for more clarity you could
> do
> 
>      git config branch.my2.remote >remote &&
>      test_must_be_empty remote
> 
> and the same for merge.
> 
> > +'
> > +
> > +test_expect_success 'test tracking setup via branch.default*' '
> > +	git config branch.autosetupmerge always &&
> > +	git config branch.defaultremote local &&
> > +	git config branch.defaultmerge main &&
> > +	git config remote.local.url . &&
> > +	git config remote.local.fetch refs/heads/*:refs/remotes/local/* &&
> > +	(git show-ref -q refs/remotes/local/main || git fetch local) &&
> > +	git branch my2 &&
> > +	git config branch.autosetupmerge false &&
> > +	test "$(git config branch.my2.remote)" = local &&
> > +	test "$(git config branch.my2.merge)" = refs/heads/main
> > +'
> > +
> >   test_expect_success 'test deleting branch deletes branch config' '
> >   	git branch -d my7 &&
> >   	test -z "$(git config branch.my7.remote)" &&
> > 
> 
> Oh, so here is the 'just test the new settings' test. Let's move that
> one to be before the two others.
> 
> Another test that could be added is one that does not change
> 'branch.autosetupmerge' but sets the new configs, and checks that the
> tracking info is *not* set.

I'll make the test suite updates as well.

Thanks for the review,

--Ben
Junio C Hamano July 30, 2021, 5:32 p.m. UTC | #3
Philippe Blain <levraiphilippeblain@gmail.com> writes:

>> diff --git a/environment.c b/environment.c
>> index 2f27008424..d550deabbd 100644
>> --- a/environment.c
>> +++ b/environment.c
>> @@ -60,6 +60,8 @@ int global_conv_flags_eol = CONV_EOL_RNDTRP_WARN;
>>   char *check_roundtrip_encoding = "SHIFT-JIS";
>>   unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
>>   enum branch_track git_branch_track = BRANCH_TRACK_REMOTE;
>> +const char* git_branch_remote = NULL;
>> +const char* git_branch_merge = NULL;

Style:
 (1) asterisk sticks to the identifier, not type, in our codebase.
 (2) do not initialize globals and statics to 0 or NULL.

> Can the new settings be implemented without adding more global variables ?

This is worth considering in the longer term.  For things like these
new configuration items and existign git_branch_track, we already
have reasonably made abstraction that branch.c is where interesting
actions happen (like setting up remote tracking, etc), so there is
no reason for them to be in environment.c or *.h to be visible to
anywhere outside branch.c file.

I wonder if it is a matter of moving git_default_branch_config() to
branch.c from config.c and make it global, while moving these global
variables also to branch.c and make them file-local?

I am still unsure without the expected use-case well documented, if
it is clear enough for users to learn how and when these new
configurations should be used (as opposed to following the
traditional triangular workflow) with only the documentation updates
in this patch, but at least I can trust others like you to give
input to polish this into a reasonable shape.

Thanks for a review (and thanks for starting the effort, Ben).
Ævar Arnfjörð Bjarmason Aug. 2, 2021, 1:02 p.m. UTC | #4
On Wed, Jul 28 2021, Ben Boeckel wrote:

> The `branch.autoSetupMerge` works well today for setting up tracking a
> local branch, but there is no easy mechanism to automatically set up a
> remote tracking situation for workflows which use a single set of
> branches for integration without specifying `--track` to every branch
> creation command or branching directly from the remote ref. This patch
> adds the following configuration values:
>
>   - `branch.defaultRemote`: initializes `branch.<name>.remote` if not
>     otherwise given;
>   - `branch.defaultMerge`: initializes `branch.<name>.merge` if not
>     otherwise given.

Not a new issue per-se, but what if you've got a branch called
defaultRemote? It seems to me that any new branch.<name>.* config closes
the door for a <name> we squat on.

Given that we have checkout.defaultRemote and this also affects
switch/checkout it seems better to continue in the checkout.* namespace
even if it wasn't for that, but given the config squatting issue
especially so....

For what it's worth I usually use the checkout.defaultRemote option
(which I added) and:

    git checkout master &&
    git branch -m master <topic-name>

See 8d7b558baeb (checkout & worktree: introduce checkout.defaultRemote,
2018-06-05). It seems to me from that patch diff that you could modify
some docs / tests for this, no? E.g. how it interacts with git-worktree.

I like this direction, but just have a concern that this is a place
where we need to consider all the UX in the area overall, and that any
options/config don't overtly interact in a bad way.
Ben Boeckel Aug. 2, 2021, 1:16 p.m. UTC | #5
On Mon, Aug 02, 2021 at 15:02:41 +0200, Ævar Arnfjörð Bjarmason wrote:
> On Wed, Jul 28 2021, Ben Boeckel wrote:
> > The `branch.autoSetupMerge` works well today for setting up tracking a
> > local branch, but there is no easy mechanism to automatically set up a
> > remote tracking situation for workflows which use a single set of
> > branches for integration without specifying `--track` to every branch
> > creation command or branching directly from the remote ref. This patch
> > adds the following configuration values:
> >
> >   - `branch.defaultRemote`: initializes `branch.<name>.remote` if not
> >     otherwise given;
> >   - `branch.defaultMerge`: initializes `branch.<name>.merge` if not
> >     otherwise given.
> 
> Not a new issue per-se, but what if you've got a branch called
> defaultRemote? It seems to me that any new branch.<name>.* config closes
> the door for a <name> we squat on.

It doesn't seem that shadowing is actually a thing:

    % git init
    Initialized empty Git repository in …/git-shadow/.git/
    % git config foo.bar true
    % git config foo.bar.baz true
    % git config --get foo.bar
    true
    % git config --get foo.bar.baz
    true

> Given that we have checkout.defaultRemote and this also affects
> switch/checkout it seems better to continue in the checkout.* namespace
> even if it wasn't for that, but given the config squatting issue
> especially so....
> 
> For what it's worth I usually use the checkout.defaultRemote option
> (which I added) and:
> 
>     git checkout master &&
>     git branch -m master <topic-name>
> 
> See 8d7b558baeb (checkout & worktree: introduce checkout.defaultRemote,
> 2018-06-05). It seems to me from that patch diff that you could modify
> some docs / tests for this, no? E.g. how it interacts with git-worktree.

I think it would be weird for `checkout.*` to affect `git branch` which
does no checkout at all. I want it to set up for simple branch creation
as well, so this would be a hole in my use case.

> I like this direction, but just have a concern that this is a place
> where we need to consider all the UX in the area overall, and that any
> options/config don't overtly interact in a bad way.

I'll have to look at adding test cases as to how it interacts with
`checkout.defaultRemote`.

Thanks,

--Ben
Ævar Arnfjörð Bjarmason Aug. 2, 2021, 3:20 p.m. UTC | #6
On Mon, Aug 02 2021, Ben Boeckel wrote:

> On Mon, Aug 02, 2021 at 15:02:41 +0200, Ævar Arnfjörð Bjarmason wrote:
>> On Wed, Jul 28 2021, Ben Boeckel wrote:
>> > The `branch.autoSetupMerge` works well today for setting up tracking a
>> > local branch, but there is no easy mechanism to automatically set up a
>> > remote tracking situation for workflows which use a single set of
>> > branches for integration without specifying `--track` to every branch
>> > creation command or branching directly from the remote ref. This patch
>> > adds the following configuration values:
>> >
>> >   - `branch.defaultRemote`: initializes `branch.<name>.remote` if not
>> >     otherwise given;
>> >   - `branch.defaultMerge`: initializes `branch.<name>.merge` if not
>> >     otherwise given.
>> 
>> Not a new issue per-se, but what if you've got a branch called
>> defaultRemote? It seems to me that any new branch.<name>.* config closes
>> the door for a <name> we squat on.
>
> It doesn't seem that shadowing is actually a thing:
>
>     % git init
>     Initialized empty Git repository in …/git-shadow/.git/
>     % git config foo.bar true
>     % git config foo.bar.baz true
>     % git config --get foo.bar
>     true
>     % git config --get foo.bar.baz
>     true

You're right, I was misrecalling (or mis-imagining) some edge case there
that doesn't exist. I also tested setting branch.defaultRemote=true and
moving a branch.defaultRemote.* branch with "git branch -m", but it also
does the right thing. Nevermind.

>> Given that we have checkout.defaultRemote and this also affects
>> switch/checkout it seems better to continue in the checkout.* namespace
>> even if it wasn't for that, but given the config squatting issue
>> especially so....
>> 
>> For what it's worth I usually use the checkout.defaultRemote option
>> (which I added) and:
>> 
>>     git checkout master &&
>>     git branch -m master <topic-name>
>> 
>> See 8d7b558baeb (checkout & worktree: introduce checkout.defaultRemote,
>> 2018-06-05). It seems to me from that patch diff that you could modify
>> some docs / tests for this, no? E.g. how it interacts with git-worktree.
>
> I think it would be weird for `checkout.*` to affect `git branch` which
> does no checkout at all. I want it to set up for simple branch creation
> as well, so this would be a hole in my use case.

*nod*, although your approach has the opposite problem of making branch
creation with "checkout" and "switch" (and presumably "worktree")
impacted by "branch.*' config.

In a way that's more sensible, in that we can imagine those commands
calling "git branch" under the hood (which msotly doesn't actually
happen, except I think in the worktree case, but it's the same
underlying APIs).

..

>> I like this direction, but just have a concern that this is a place
>> where we need to consider all the UX in the area overall, and that any
>> options/config don't overtly interact in a bad way.
>
> I'll have to look at adding test cases as to how it interacts with
> `checkout.defaultRemote`.
>
> Thanks,

....right, none of that mess is a showstopper, I'm just prodding you to
look at if any of those edge cases are made better/worse by these
additions. Thanks!
diff mbox series

Patch

diff --git a/Documentation/config/branch.txt b/Documentation/config/branch.txt
index cc5f3249fc..ab5cd2c1ed 100644
--- a/Documentation/config/branch.txt
+++ b/Documentation/config/branch.txt
@@ -1,3 +1,17 @@ 
+branch.defaultRemote::
+	Tells 'git branch', 'git switch' and 'git checkout' to set up new branches
+	so that it will track a branch on the specified remote. This can be
+	used, in conjunction with `branch.defaultMerge`, in projects where
+	branches tend to target a single branch. This will be used to
+	initialize the "branch.<name>.remote" setting.
+
+branch.defaultMerge::
+	Tells 'git branch', 'git switch' and 'git checkout' to set up new branches
+	so that it will track a branch with this name. This can be used, in
+	conjunction with `branch.defaultRemote` in projects where branches tend
+	to target a single branch. This will be used to initialize the
+	"branch.<name>.merge" setting.
+
 branch.autoSetupMerge::
 	Tells 'git branch', 'git switch' and 'git checkout' to set up new branches
 	so that linkgit:git-pull[1] will appropriately merge from the
diff --git a/branch.c b/branch.c
index 7a88a4861e..097d5af647 100644
--- a/branch.c
+++ b/branch.c
@@ -60,6 +60,8 @@  int install_branch_config(int flag, const char *local, const char *origin, const
 	const char *shortname = NULL;
 	struct strbuf key = STRBUF_INIT;
 	int rebasing = should_setup_rebase(origin);
+	const char *actual_origin = origin ? origin : git_branch_remote;
+	const char *actual_remote = remote ? remote : git_branch_merge;
 
 	if (skip_prefix(remote, "refs/heads/", &shortname)
 	    && !strcmp(local, shortname)
@@ -70,12 +72,12 @@  int install_branch_config(int flag, const char *local, const char *origin, const
 	}
 
 	strbuf_addf(&key, "branch.%s.remote", local);
-	if (git_config_set_gently(key.buf, origin ? origin : ".") < 0)
+	if (git_config_set_gently(key.buf, actual_origin ? actual_origin : ".") < 0)
 		goto out_err;
 
 	strbuf_reset(&key);
 	strbuf_addf(&key, "branch.%s.merge", local);
-	if (git_config_set_gently(key.buf, remote) < 0)
+	if (git_config_set_gently(key.buf, actual_remote) < 0)
 		goto out_err;
 
 	if (rebasing) {
@@ -88,27 +90,27 @@  int install_branch_config(int flag, const char *local, const char *origin, const
 
 	if (flag & BRANCH_CONFIG_VERBOSE) {
 		if (shortname) {
-			if (origin)
+			if (actual_origin)
 				printf_ln(rebasing ?
 					  _("Branch '%s' set up to track remote branch '%s' from '%s' by rebasing.") :
 					  _("Branch '%s' set up to track remote branch '%s' from '%s'."),
-					  local, shortname, origin);
+					  local, shortname, actual_origin);
 			else
 				printf_ln(rebasing ?
 					  _("Branch '%s' set up to track local branch '%s' by rebasing.") :
 					  _("Branch '%s' set up to track local branch '%s'."),
 					  local, shortname);
 		} else {
-			if (origin)
+			if (actual_origin)
 				printf_ln(rebasing ?
 					  _("Branch '%s' set up to track remote ref '%s' by rebasing.") :
 					  _("Branch '%s' set up to track remote ref '%s'."),
-					  local, remote);
+					  local, actual_remote);
 			else
 				printf_ln(rebasing ?
 					  _("Branch '%s' set up to track local ref '%s' by rebasing.") :
 					  _("Branch '%s' set up to track local ref '%s'."),
-					  local, remote);
+					  local, actual_remote);
 		}
 	}
 
@@ -119,9 +121,9 @@  int install_branch_config(int flag, const char *local, const char *origin, const
 	error(_("Unable to write upstream branch configuration"));
 
 	advise(_(tracking_advice),
-	       origin ? origin : "",
-	       origin ? "/" : "",
-	       shortname ? shortname : remote);
+	       actual_origin ? actual_origin : "",
+	       actual_origin ? "/" : "",
+	       shortname ? shortname : actual_remote);
 
 	return -1;
 }
diff --git a/branch.h b/branch.h
index df0be61506..7d7990dda7 100644
--- a/branch.h
+++ b/branch.h
@@ -14,6 +14,8 @@  enum branch_track {
 };
 
 extern enum branch_track git_branch_track;
+extern const char* git_branch_remote;
+extern const char* git_branch_merge;
 
 /* Functions for acting on the information about branches. */
 
diff --git a/config.c b/config.c
index f33abeab85..a46c5a43a1 100644
--- a/config.c
+++ b/config.c
@@ -1599,6 +1599,16 @@  static int git_default_branch_config(const char *var, const char *value)
 			return error(_("malformed value for %s"), var);
 		return 0;
 	}
+	if (!strcmp(var, "branch.defaultremote")) {
+		if (!value)
+			return config_error_nonbool(var);
+		return git_config_string(&git_branch_remote, var, value);
+	}
+	if (!strcmp(var, "branch.defaultmerge")) {
+		if (!value)
+			return config_error_nonbool(var);
+		return git_config_string(&git_branch_merge, var, value);
+	}
 
 	/* Add other config variables here and to Documentation/config.txt. */
 	return 0;
diff --git a/environment.c b/environment.c
index 2f27008424..d550deabbd 100644
--- a/environment.c
+++ b/environment.c
@@ -60,6 +60,8 @@  int global_conv_flags_eol = CONV_EOL_RNDTRP_WARN;
 char *check_roundtrip_encoding = "SHIFT-JIS";
 unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
 enum branch_track git_branch_track = BRANCH_TRACK_REMOTE;
+const char* git_branch_remote = NULL;
+const char* git_branch_merge = NULL;
 enum rebase_setup_type autorebase = AUTOREBASE_NEVER;
 enum push_default_type push_default = PUSH_DEFAULT_UNSPECIFIED;
 #ifndef OBJECT_CREATION_MODE
diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index cc4b10236e..82137e8451 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -797,6 +797,45 @@  test_expect_success 'test tracking setup via --track but deeper' '
 	test "$(git config branch.my7.merge)" = refs/heads/o/o
 '
 
+test_expect_success 'test tracking setup via branch.default* and --track' '
+	git config branch.autosetupmerge always &&
+	git config branch.defaultremote local &&
+	git config branch.defaultmerge main &&
+	git config remote.local.url . &&
+	git config remote.local.fetch refs/heads/*:refs/remotes/local/* &&
+	(git show-ref -q refs/remotes/local/main || git fetch local) &&
+	git branch --track other/foo my2 &&
+	git config branch.autosetupmerge false &&
+	test "$(git config branch.my2.remote)" = other &&
+	test "$(git config branch.my2.merge)" = refs/heads/foo
+'
+
+test_expect_success 'test tracking setup via branch.default* and --no-track' '
+	git config branch.autosetupmerge always &&
+	git config branch.defaultremote local &&
+	git config branch.defaultmerge main &&
+	git config remote.local.url . &&
+	git config remote.local.fetch refs/heads/*:refs/remotes/local/* &&
+	(git show-ref -q refs/remotes/local/main || git fetch local) &&
+	git branch --no-track my2 &&
+	git config branch.autosetupmerge false &&
+	! test "$(git config branch.my2.remote)" = local &&
+	! test "$(git config branch.my2.merge)" = refs/heads/main
+'
+
+test_expect_success 'test tracking setup via branch.default*' '
+	git config branch.autosetupmerge always &&
+	git config branch.defaultremote local &&
+	git config branch.defaultmerge main &&
+	git config remote.local.url . &&
+	git config remote.local.fetch refs/heads/*:refs/remotes/local/* &&
+	(git show-ref -q refs/remotes/local/main || git fetch local) &&
+	git branch my2 &&
+	git config branch.autosetupmerge false &&
+	test "$(git config branch.my2.remote)" = local &&
+	test "$(git config branch.my2.merge)" = refs/heads/main
+'
+
 test_expect_success 'test deleting branch deletes branch config' '
 	git branch -d my7 &&
 	test -z "$(git config branch.my7.remote)" &&