Re: [PATCH/RFC] submodule: add ability to shallowly clone any branch in a submodule

[Cole <cole.minnaar@gmail.com>]

Excerpts from Jens Lehmann's message of 2014-09-11 21:21:04 +0200:
> Am 11.09.2014 um 19:11 schrieb Cole Minnaar:
> > Currently when specifying the `--depth` option to the 'submodule add'
> > command, it can only create a shallow submodule clone of the currently active
> > branch from the cloned repository. If a branch is specified using the
> > `--branch` command, the 'submodule add' will result in an error as the
> > branch will not exist in the cloned repository. Subsequently, if a
> > repository is cloned which contains submodules, and both the `--depth` and
> > `--recursive` options are specified, the top level repository will be
> > cloned using the specified depth, but each submodule will be cloned in
> > its entirety.
> >
> > Added the ability to shallowly clone any branch as a submodule, not just
> > the current active branch from the cloned repository. Also includes the
> > ability to shallowly clone a repository and all its submodules.
> > Added support to the 'submodule add' and 'submodule update' command to handle
> > `--no-single-branch`, which is then passed to the clone command in order
> > to setup remote-tracking branches in the shallowly cloned submodules.
> >
> > Signed-off-by: Cole Minnaar <cole.minnaar@gmail.com>
> > ---
> 
> Sorry for not having found the time to respond to your first message,
> great to see you started working on this.
> 
> While I have no objection to what you are trying to achieve here, I
> think you are doing too much in a single commit. At least the changes
> to "git clone" (passing --depth and --no-single-branch on to the "git
> submodule update" when called with "--recurse-submodules") and the
> "git submodule" script should be separated into their own commits.
> 
> And from a cursory glance I wonder if "git submodule update" with
> branch should always imply --no-singe-branch? Then maybe we do not
> need to add this option to the submodule script but simply always
> add it when called with --branch?

Hi Jens,

Thanks for the feedback, really appreciate it, and will try to reformat
the patches as you have asked.

When you say you would like the patches split, do you mean into two
separate threads, or just different patches part of the same thread?

As for --no-single-branch on 'git submodule update', I didn't want to
break existing functionality, but if you would prefer that to be the
default I can make it so.

Also if there is anything else you are currently looking at regarding
submodules or thinking about, I would be glad to hear about it or to try
look at it while I am working on these changes. Or if there is anything
you can think of for me to check with regards to these changes that
would also be appreciated.

I am still quite new to some of the git terms and functionality, 
so please excuse me if I do get anything wrong or do not fully understand.

/Cole
> 
> >   Documentation/git-clone.txt     |  6 +++++-
> >   Documentation/git-submodule.txt |  8 ++++++--
> >   builtin/clone.c                 | 15 +++++++++------
> >   git-submodule.sh                | 24 ++++++++++++++++++++----
> >   t/t7400-submodule-basic.sh      | 33 ++++++++++++++++++++++++++++++++-
> >   5 files changed, 72 insertions(+), 14 deletions(-)
> >
> > diff --git a/Documentation/git-clone.txt b/Documentation/git-clone.txt
> > index 0363d00..5eef11c 100644
> > --- a/Documentation/git-clone.txt
> > +++ b/Documentation/git-clone.txt
> > @@ -178,7 +178,9 @@ objects from the source repository into a pack in the cloned repository.
> >
> >   --depth <depth>::
> >       Create a 'shallow' clone with a history truncated to the
> > -    specified number of revisions.
> > +    specified number of revisions. If `--recursive` was also specified,
> > +    the depth value will be passed to all submodules within when
> > +    cloning.
> >
> >   --[no-]single-branch::
> >       Clone only the history leading to the tip of a single branch,
> > @@ -192,6 +194,8 @@ objects from the source repository into a pack in the cloned repository.
> >       initial cloning.  If the HEAD at the remote did not point at any
> >       branch when `--single-branch` clone was made, no remote-tracking
> >       branch is created.
> > +    If `--recursive` was also specified, this option will also be passed
> > +    to all submodules when cloning.
> >
> >   --recursive::
> >   --recurse-submodules::
> > diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
> > index 8e6af65..176f150 100644
> > --- a/Documentation/git-submodule.txt
> > +++ b/Documentation/git-submodule.txt
> > @@ -10,13 +10,14 @@ SYNOPSIS
> >   --------
> >   [verse]
> >   'git submodule' [--quiet] add [-b <branch>] [-f|--force] [--name <name>]
> > -          [--reference <repository>] [--depth <depth>] [--] <repository> [<path>]
> > +          [--reference <repository>] [--depth <depth>] [--no-single-branch]
> > +          [--] <repository> [<path>]
> >   'git submodule' [--quiet] status [--cached] [--recursive] [--] [<path>...]
> >   'git submodule' [--quiet] init [--] [<path>...]
> >   'git submodule' [--quiet] deinit [-f|--force] [--] <path>...
> >   'git submodule' [--quiet] update [--init] [--remote] [-N|--no-fetch]
> >             [-f|--force] [--rebase|--merge] [--reference <repository>]
> > -          [--depth <depth>] [--recursive] [--] [<path>...]
> > +          [--recursive] [--depth <depth>] [--no-single-branch] [--] [<path>...]
> >   'git submodule' [--quiet] summary [--cached|--files] [(-n|--summary-limit) <n>]
> >             [commit] [--] [<path>...]
> >   'git submodule' [--quiet] foreach [--recursive] <command>
> > @@ -354,6 +355,9 @@ for linkgit:git-clone[1]'s `--reference` and `--shared` options carefully.
> >       clone with a history truncated to the specified number of revisions.
> >       See linkgit:git-clone[1]
> >
> > +--no-single-branch::
> > +    This option is valid for add and update commands. Fetch histories near the tips
> > +    of all branches and create remote-tracking branches in the submodule.
> >
> >   <path>...::
> >       Paths to submodule(s). When specified this will restrict the command
> > diff --git a/builtin/clone.c b/builtin/clone.c
> > index dd4092b..b27917c 100644
> > --- a/builtin/clone.c
> > +++ b/builtin/clone.c
> > @@ -48,6 +48,7 @@ static int option_verbosity;
> >   static int option_progress = -1;
> >   static struct string_list option_config;
> >   static struct string_list option_reference;
> > +static struct argv_array argv_submodule_cmd = ARGV_ARRAY_INIT;
> >
> >   static int opt_parse_reference(const struct option *opt, const char *arg, int unset)
> >   {
> > @@ -100,10 +101,6 @@ static struct option builtin_clone_options[] = {
> >       OPT_END()
> >   };
> >
> > -static const char *argv_submodule[] = {
> > -    "submodule", "update", "--init", "--recursive", NULL
> > -};
> > -
> >   static char *get_repo_path(const char *repo, int *is_bundle)
> >   {
> >       static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
> > @@ -663,8 +660,14 @@ static int checkout(void)
> >       err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
> >                  sha1_to_hex(sha1), "1", NULL);
> >
> > -    if (!err && option_recursive)
> > -        err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
> > +    if (!err && option_recursive) {
> > +        argv_array_pushl(&argv_submodule_cmd, "submodule", "update", "--init", "--recursive", NULL);
> > +        if (option_depth)
> > +            argv_array_pushf(&argv_submodule_cmd, "--depth=%d", atoi(option_depth));
> > +        if (!option_single_branch)
> > +            argv_array_pushl(&argv_submodule_cmd, "--no-single-branch", NULL);
> > +        err = run_command_v_opt(argv_submodule_cmd.argv, RUN_GIT_CMD);
> > +    }
> >
> >       return err;
> >   }
> > diff --git a/git-submodule.sh b/git-submodule.sh
> > index 9245abf..9c0c858 100755
> > --- a/git-submodule.sh
> > +++ b/git-submodule.sh
> > @@ -5,11 +5,11 @@
> >   # Copyright (c) 2007 Lars Hjemli
> >
> >   dashless=$(basename "$0" | sed -e 's/-/ /')
> > -USAGE="[--quiet] add [-b <branch>] [-f|--force] [--name <name>] [--reference <repository>] [--] <repository> [<path>]
> > +USAGE="[--quiet] add [-b <branch>] [-f|--force] [--name <name>] [--reference <repository>] [--depth <depth>] [--no-single-branch] [--] <repository> [<path>]
> >      or: $dashless [--quiet] status [--cached] [--recursive] [--] [<path>...]
> >      or: $dashless [--quiet] init [--] [<path>...]
> >      or: $dashless [--quiet] deinit [-f|--force] [--] <path>...
> > -   or: $dashless [--quiet] update [--init] [--remote] [-N|--no-fetch] [-f|--force] [--checkout|--merge|--rebase] [--reference <repository>] [--recursive] [--] [<path>...]
> > +   or: $dashless [--quiet] update [--init] [--remote] [-N|--no-fetch] [-f|--force] [--checkout|--merge|--rebase] [--reference <repository>] [--recursive] [--depth <depth>] [--no-single-branch] [--] [<path>...]
> >      or: $dashless [--quiet] summary [--cached|--files] [--summary-limit <n>] [commit] [--] [<path>...]
> >      or: $dashless [--quiet] foreach [--recursive] <command>
> >      or: $dashless [--quiet] sync [--recursive] [--] [<path>...]"
> > @@ -259,6 +259,13 @@ module_clone()
> >       url=$3
> >       reference="$4"
> >       depth="$5"
> > +    clone_branch=
> > +    if test -n "$6"
> > +    then
> > +        clone_branch="--branch=$6"
> > +    fi
> > +
> > +    no_single_branch="$7"
> >       quiet=
> >       if test -n "$GIT_QUIET"
> >       then
> > @@ -282,6 +289,7 @@ module_clone()
> >           (
> >               clear_local_git_env
> >               git clone $quiet ${depth:+"$depth"} -n ${reference:+"$reference"} \
> > +                ${clone_branch:+"$clone_branch"} ${no_single_branch:+"$no_single_branch"} \
> >                   --separate-git-dir "$gitdir" "$url" "$sm_path"
> >           ) ||
> >           die "$(eval_gettext "Clone of '\$url' into submodule path '\$sm_path' failed")"
> > @@ -328,6 +336,7 @@ cmd_add()
> >   {
> >       # parse $args after "submodule ... add".
> >       reference_path=
> > +    no_single_branch=
> >       while test $# -ne 0
> >       do
> >           case "$1" in
> > @@ -363,6 +372,9 @@ cmd_add()
> >           --depth=*)
> >               depth=$1
> >               ;;
> > +        --no-single-branch)
> > +            no_single_branch="--no-single-branch"
> > +            ;;
> >           --)
> >               shift
> >               break
> > @@ -472,7 +484,7 @@ Use -f if you really want to add it." >&2
> >                   echo "$(eval_gettext "Reactivating local git directory for submodule '\$sm_name'.")"
> >               fi
> >           fi
> > -        module_clone "$sm_path" "$sm_name" "$realrepo" "$reference" "$depth" || exit
> > +        module_clone "$sm_path" "$sm_name" "$realrepo" "$reference" "$depth" "$branch" "$no_single_branch" || exit
> >           (
> >               clear_local_git_env
> >               cd "$sm_path" &&
> > @@ -724,6 +736,7 @@ cmd_deinit()
> >   cmd_update()
> >   {
> >       # parse $args after "submodule ... update".
> > +    no_single_branch=
> >       while test $# -ne 0
> >       do
> >           case "$1" in
> > @@ -770,6 +783,9 @@ cmd_update()
> >           --depth=*)
> >               depth=$1
> >               ;;
> > +        --no-single-branch)
> > +            no_single_branch="--no-single-branch"
> > +            ;;
> >           --)
> >               shift
> >               break
> > @@ -834,7 +850,7 @@ Maybe you want to use 'update --init'?")"
> >
> >           if ! test -d "$sm_path"/.git && ! test -f "$sm_path"/.git
> >           then
> > -            module_clone "$sm_path" "$name" "$url" "$reference" "$depth" || exit
> > +            module_clone "$sm_path" "$name" "$url" "$reference" "$depth" "$branch" "$no_single_branch" || exit
> >               cloned_modules="$cloned_modules;$name"
> >               subsha1=
> >           else
> > diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
> > index 7c88245..81c05ae 100755
> > --- a/t/t7400-submodule-basic.sh
> > +++ b/t/t7400-submodule-basic.sh
> > @@ -136,7 +136,6 @@ test_expect_success 'submodule add --branch' '
> >       echo "refs/heads/initial" >expect-head &&
> >       cat <<-\EOF >expect-heads &&
> >       refs/heads/initial
> > -    refs/heads/master
> >       EOF
> >       >empty &&
> >
> > @@ -982,5 +981,37 @@ test_expect_success 'submodule add clone shallow submodule' '
> >       )
> >   '
> >
> > +test_expect_success 'submodule add --branch --depth' '
> > +    (
> > +        cd addtest2 &&
> > +        git submodule add -b initial --depth 1 -- file://"$submodurl" submod-branch-depth &&
> > +        test "initial" = "$(git config -f .gitmodules submodule.submod-branch-depth.branch)" &&
> > +        (
> > +            cd submod-branch-depth &&
> > +            test 1 = $(git log --oneline | wc -l)
> > +        )
> > +    )
> > +'
> > +
> > +cat >remote <<\EOF
> > +  origin/HEAD -> origin/second
> > +  origin/initial
> > +  origin/master
> > +  origin/second
> > +EOF
> > +
> > +test_expect_success 'submodule add --branch --depth --no-single-branch' '
> > +    (
> > +        cd addtest2 &&
> > +        git submodule add -b initial --depth 1 --no-single-branch -- file://"$submodurl" submod-branch-depth-all &&
> > +        test "initial" = "$(git config -f .gitmodules submodule.submod-branch-depth-all.branch)" &&
> > +        (
> > +            cd submod-branch-depth-all &&
> > +            test 1 = $(git log --oneline | wc -l)
> > +            git branch -r >../../remote-out
> > +        )
> > +    ) &&
> > +    test_cmp remote remote-out
> > +'
> >
> >   test_done
> >