An earlier addition of "sanitize_submodule_env" with 14111fc4 (git:
submodule honor -c credential.* from command line, 2016-02-29)
turned out to be a convoluted no-op; implement what it wanted to do
correctly, and stop filtering settings given via "git -c var=val".
* jk/submodule-c-credential:
submodule: stop sanitizing config options
submodule: use prepare_submodule_repo_env consistently
submodule--helper: move config-sanitizing to submodule.c
submodule: export sanitized GIT_CONFIG_PARAMETERS
t5550: break submodule config test into multiple sub-tests
t5550: fix typo in $HTTPD_URL
Correct faulty recommendation to use "git submodule deinit ." when
de-initialising all submodules, which would result in a strange
error message in a pathological corner case.
* sb/submodule-deinit-all:
submodule deinit: require '--all' instead of '.' for all submodules
Update of "git submodule" to move pieces of logic to C continues.
* sb/submodule-init:
submodule init: redirect stdout to stderr
submodule--helper update-clone: abort gracefully on missing .gitmodules
submodule init: fail gracefully with a missing .gitmodules file
submodule: port init from shell to C
submodule: port resolve_relative_url from shell to C
The point of having a whitelist of command-line config
options to pass to submodules was two-fold:
1. It prevented obvious nonsense like using core.worktree
for multiple repos.
2. It could prevent surprise when the user did not mean
for the options to leak to the submodules (e.g.,
http.sslverify=false).
For case 1, the answer is mostly "if it hurts, don't do
that". For case 2, we can note that any such example has a
matching inverted surprise (e.g., a user who meant
http.sslverify=true to apply everywhere, but it didn't).
So this whitelist is probably not giving us any benefit, and
is already creating a hassle as people propose things to put
on it. Let's just drop it entirely.
Note that we still need to keep a special code path for
"prepare the submodule environment", because we still have
to take care to pass through $GIT_CONFIG_PARAMETERS (and
block the rest of the repo-specific environment variables).
We can do this easily from within the submodule shell
script, which lets us drop the submodule--helper option
entirely (and it's OK to do so because as a "--" program, it
is entirely a private implementation detail).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The discussion in [1] pointed out that '.' is a faulty suggestion as
there is a corner case where it fails:
> "submodule deinit ." may have "worked" in the sense that you would
> have at least one path in your tree and avoided this "nothing
> matches" most of the time. It would have still failed with the
> exactly same error if run in an empty repository, i.e.
>
> $ E=/var/tmp/x/empty && rm -fr "$E" && mkdir -p "$E" && cd "$E"
> $ git init
> $ rungit v2.6.6 submodule deinit .
> error: pathspec '.' did not match any file(s) known to git.
> Did you forget to 'git add'?
> $ >file && git add file
> $ rungit v2.6.6 submodule deinit .
> $ echo $?
> 0
So instead of a pathspec add the '--all' option to deinit all submodules
and add a test to check for the corner case of an empty repository.
The code only needs to learn about the '--all' option and doesn't
require further changes as `git submodule--helper list "$@"` will list
all submodules when "$@" is empty.
[1] http://news.gmane.org/gmane.comp.version-control.git/289535
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 14111fc (git: submodule honor -c credential.* from
command line, 2016-02-29) taught git-submodule.sh to save
the sanitized value of $GIT_CONFIG_PARAMETERS when clearing
the environment for a submodule. However, it failed to
export the result, meaning that it had no effect for any
sub-programs.
We didn't catch this in our initial tests because we checked
only the "clone" case, which does not go through the shell
script at all. Provoking "git submodule update" to do a
fetch demonstrates the bug.
Noticed-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git submodule" reports the paths of submodules the command
recurses into, but this was incorrect when the command was not run
from the root level of the superproject.
* sb/submodule-path-misc-bugs:
t7407: make expectation as clear as possible
submodule update: test recursive path reporting from subdirectory
submodule update: align reporting path for custom command execution
submodule status: correct path handling in recursive submodules
submodule update --init: correct path handling in recursive submodules
submodule foreach: correct path display in recursive submodules
By having the `submodule init` functionality in C, we can reference it
easier from other parts in the code in later patches. The code is split
up to have one function to initialize one submodule and a calling function
that takes care of the rest, such as argument handling and translating the
arguments to the paths of the submodules.
This is the first submodule subcommand that is fully converted to C
except for the usage string, so this is actually removing a call to
the `submodule--helper list` function, which is supposed to be used in
this transition. Instead we'll make a direct call to `module_list_compute`.
An explanation why we need to edit the prefixes in cmd_update in
git-submodule.sh in this patch:
By having no processing in the shell part, we need to convey the notion
of wt_prefix and prefix to the C parts, which former patches punted on
and did the processing of displaying path in the shell.
`wt_prefix` used to hold the path from the repository root to the current
directory, e.g. wt_prefix would be t/ if the user invoked the
`git submodule` command in ~/repo/t and ~repo is the GIT_DIR.
`prefix` used to hold the relative path from the repository root to the
operation, e.g. if you have recursive submodules, the shell script would
modify the `prefix` in each recursive step by adding the submodule path.
We will pass `wt_prefix` into the C helper via `git -C <dir>` as that
will setup git in the directory the user actually called git-submodule.sh
from. The `prefix` will be passed in via the `--prefix` option.
Having `prefix` and `wt_prefix` relative to the GIT_DIR of the
calling superproject is unfortunate with this patch as the C code doesn't
know about a possible recursion from a superproject via `submodule update
--init --recursive`.
To fix this, we change the meaning of `wt_prefix` to point to the current
project instead of the superproject and `prefix` to include any relative
paths issues in the superproject. That way `prefix` will become the leading
part for displaying paths and `wt_prefix` will be empty in recursive
calls for now.
The new notion of `wt_prefix` and `prefix` still allows us to reconstruct
the calling directory in the superproject by just traveling reverse of
`prefix`.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Later on we want to automatically call `git submodule init` from
other commands, such that the users don't have to initialize the
submodule themselves. As these other commands are written in C
already, we'd need the init functionality in C, too. The
`resolve_relative_url` function is a large part of that init
functionality, so start by porting this function to C.
To create the tests in t0060, the function `resolve_relative_url`
was temporarily enhanced to write all inputs and output to disk
when running the test suite. The added tests in this patch are
a small selection thereof.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git submodule" reports the paths of submodules the command
recurses into, but this was incorrect when the command was not run
from the root level of the superproject.
Any further comments? Otherwise will merge to 'next'.
* sb/submodule-path-misc-bugs: (600 commits)
t7407: make expectation as clear as possible
submodule update: test recursive path reporting from subdirectory
submodule update: align reporting path for custom command execution
submodule status: correct path handling in recursive submodules
submodule update --init: correct path handling in recursive submodules
submodule foreach: correct path display in recursive submodules
Git 2.8
Documentation: fix git-p4 AsciiDoc formatting
mingw: skip some tests in t9115 due to file name issues
t1300: fix the new --show-origin tests on Windows
t1300-repo-config: make it resilient to being run via 'sh -x'
config --show-origin: report paths with forward slashes
submodule: fix regression for deinit without submodules
l10n: pt_PT: Update and add new translations
l10n: ca.po: update translation
Git 2.8-rc4
Documentation: fix broken linkgit to git-config
Documentation: use ASCII quotation marks in git-p4
Revert "config.mak.uname: use clang for Mac OS X 10.6"
git-compat-util: st_add4: work around gcc 4.2.x compiler crash
...
"git -c credential.<var>=<value> submodule" can now be used to
propagate configuration variables related to credential helper
down to the submodules.
* jk/submodule-c-credential:
git_config_push_parameter: handle empty GIT_CONFIG_PARAMETERS
git: submodule honor -c credential.* from command line
quote: implement sq_quotef()
submodule: fix segmentation fault in submodule--helper clone
submodule: fix submodule--helper clone usage
submodule: check argc count for git submodule--helper clone
submodule: don't pass empty string arguments to submodule--helper clone
A major part of "git submodule update" has been ported to C to take
advantage of the recently added framework to run download tasks in
parallel.
* sb/submodule-parallel-update:
clone: allow an explicit argument for parallel submodule clones
submodule update: expose parallelism to the user
submodule helper: remove double 'fatal: ' prefix
git submodule update: have a dedicated helper for cloning
run_processes_parallel: rename parameters for the callbacks
run_processes_parallel: treat output of children as byte array
submodule update: direct error message to stderr
fetching submodules: respect `submodule.fetchJobs` config option
submodule-config: drop check against NULL
submodule-config: keep update strategy around
In the predefined actions (merge, rebase, none, checkout), we use
the display path, which is relative to the current working directory.
Also use the display path when running a custom command.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The new test which is a replica of the previous test except
that it executes from a sub directory. Prior to this patch
the test failed by having too many '../' prefixed:
--- expect 2016-03-29 19:02:33.087336115 +0000
+++ actual 2016-03-29 19:02:33.359343311 +0000
@@ -1,7 +1,7 @@
b23f134787d96fae589a6b76da41f4db112fc8db ../nested1 (heads/master)
-+25d56d1ddfb35c3e91ff7d8f12331c2e53147dcc ../nested1/nested2 (file2)
- 5ec83512b76a0b8170b899f8e643913c3e9b72d9 ../nested1/nested2/nested3 (heads/master)
- 509f622a4f36a3e472affcf28fa959174f3dd5b5 ../nested1/nested2/nested3/submodule (heads/master)
++25d56d1ddfb35c3e91ff7d8f12331c2e53147dcc ../../nested1/nested2 (file2)
+ 5ec83512b76a0b8170b899f8e643913c3e9b72d9 ../../../nested1/nested2/nested3 (heads/master)
+ 509f622a4f36a3e472affcf28fa959174f3dd5b5 ../../../../nested1/nested2/nested3/submodule (heads/master)
0c90624ab7f1aaa301d3bb79f60dcfed1ec4897f ../sub1 (0c90624)
0c90624ab7f1aaa301d3bb79f60dcfed1ec4897f ../sub2 (0c90624)
509f622a4f36a3e472affcf28fa959174f3dd5b5 ../sub3 (heads/master)
The path code in question:
displaypath=$(relative_path "$prefix$sm_path")
prefix=$displaypath
if recursive:
eval cmd_status
That way we change `prefix` each iteration to contain another
'../', because of the the relative_path computation is done
on an already computed relative path.
We must call relative_path exactly once with `wt_prefix` non empty.
Further calls in recursive instances to to calculate the displaypath
already incorporate the correct prefix from before. Fix the issue by
clearing `wt_prefix` in recursive calls.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When calling `git submodule init` from a recursive instance of
`git submodule update --recursive`, the reported path is wrong as it
skips the nested submodules.
The new test demonstrates a failure in the code prior to this patch.
Instead of getting the expected
Submodule 'submodule' (${pwd}/submodule) registered for path '../super/submodule'
the `super` directory is omitted and you get
Submodule 'submodule' (${pwd}/submodule) registered for path '../submodule'
instead.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `prefix` was put in front of the display path unconditionally.
This is wrong as any relative path computation would need to be at
the front, so include the prefix into the display path.
The new test replicates the previous test with the difference of executing
from a sub directory. By executing from a sub directory all we would
expect all displayed paths to be prefixed by '../'.
Prior to this patch the test would report
Entering 'nested1/nested2/../nested3'
instead of the expected
Entering '../nested1/nested2/nested3'
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Due to the way that the git-submodule code works, it clears all local
git environment variables before entering submodules. This is normally
a good thing since we want to clear settings such as GIT_WORKTREE and
other variables which would affect the operation of submodule commands.
However, GIT_CONFIG_PARAMETERS is special, and we actually do want to
preserve these settings. However, we do not want to preserve all
configuration as many things should be left specific to the parent
project.
Add a git submodule--helper function, sanitize-config, which shall be
used to sanitize GIT_CONFIG_PARAMETERS, removing all key/value pairs
except a small subset that are known to be safe and necessary.
Replace all the calls to clear_local_git_env with a wrapped function
that filters GIT_CONFIG_PARAMETERS using the new helper and then
restores it to the filtered subset after clearing the rest of the
environment.
Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When --reference or --depth are unused, the current git-submodule.sh
results in empty "" arguments appended to the end of the argv array
inside git submodule--helper clone. This is not caught because the argc
count is not checked today.
Fix git-submodule.sh to only pass an argument when --reference or
--depth are used, preventing the addition of two empty string arguments
on the tail of the argv array.
Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Expose possible parallelism either via the "--jobs" CLI parameter or
the "submodule.fetchJobs" setting.
By having the variable initialized to -1, we make sure 0 can be passed
into the parallel processing machine, which will then pick as many parallel
workers as there are CPUs.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This introduces a new helper function in git submodule--helper
which takes care of cloning all submodules, which we want to
parallelize eventually.
Some tests (such as empty URL, update_mode=none) are required in the
helper to make the decision for cloning. These checks have been
moved into the C function as well (no need to repeat them in the
shell script).
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reroute the error message for specified but initialized submodules
to stderr instead of stdout.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When reviewing a change that also updates a submodule in Gerrit, a
common review practice is to download and cherry-pick the patch
locally to test it. However when testing it locally, the 'git
submodule update' may fail fetching the correct submodule sha1 as
the corresponding commit in the submodule is not yet part of the
project history, but also just a proposed change.
If $sha1 was not part of the default fetch, we try to fetch the $sha1
directly. Some servers however do not support direct fetch by sha1,
which leads git-fetch to fail quickly. We can fail ourselves here as
the still missing sha1 would lead to a failure later in the checkout
stage anyway, so failing here is as good as we can get.
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The infrastructure to rewrite "git submodule" in C is being built
incrementally. Let's polish these early parts well enough and make
them graduate to 'next' and 'master', so that the more involved
follow-up can start cooking on a solid ground.
* sb/submodule-helper:
submodule: rewrite `module_clone` shell function in C
submodule: rewrite `module_name` shell function in C
submodule: rewrite `module_list` shell function in C
Some protocols (like git-remote-ext) can execute arbitrary
code found in the URL. The URLs that submodules use may come
from arbitrary sources (e.g., .gitmodules files in a remote
repository). Let's restrict submodules to fetching from a
known-good subset of protocols.
Note that we apply this restriction to all submodule
commands, whether the URL comes from .gitmodules or not.
This is more restrictive than we need to be; for example, in
the tests we run:
git submodule add ext::...
which should be trusted, as the URL comes directly from the
command line provided by the user. But doing it this way is
simpler, and makes it much less likely that we would miss a
case. And since such protocols should be an exception
(especially because nobody who clones from them will be able
to update the submodules!), it's not likely to inconvenience
anyone in practice.
Reported-by: Blake Burkhart <bburky@bburky.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This reimplements the helper function `module_clone` in shell
in C as `clone`. This functionality is needed for converting
`git submodule update` later on, which we want to add threading
to.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This implements the helper `name` in C instead of shell,
yielding a nice performance boost.
Before this patch, I measured a time (best out of three):
$ time ./t7400-submodule-basic.sh >/dev/null
real 0m11.066s
user 0m3.348s
sys 0m8.534s
With this patch applied I measured (also best out of three)
$ time ./t7400-submodule-basic.sh >/dev/null
real 0m10.063s
user 0m3.044s
sys 0m7.487s
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most of the submodule operations work on a set of submodules.
Calculating and using this set is usually done via:
module_list "$@" | {
while read mode sha1 stage sm_path
do
# the actual operation
done
}
Currently the function `module_list` is implemented in the
git-submodule.sh as a shell script wrapping a perl script.
The rewrite is in C, such that it is faster and can later be
easily adapted when other functions are rewritten in C.
git-submodule.sh, similar to the builtin commands, will navigate
to the top-most directory of the repository and keep the
subdirectory as a variable. As the helper is called from
within the git-submodule.sh script, we are already navigated
to the root level, but the path arguments are still relative
to the subdirectory we were in when calling git-submodule.sh.
That's why there is a `--prefix` option pointing to an alternative
path which to anchor relative path arguments.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Acked-by: Chris Packham <judge.packham@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we add a new submodule the path of the submodule is being
normalized. We fail to normalize multiple adjacent '/./', though.
Thus 'path/to/././submodule' will become 'path/to/./submodule' where
it should be 'path/to/submodule' instead.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Acked-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
SysV-derived implementation of "echo" interprets some backslash
sequences as special instruction, e.g. "echo 'ab\c'" shows an
incomplete line with 'a' and 'b' on it. Avoid using it when showing
a path-like values in the script.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The construct is error-prone; "test" being built-in in most modern
shells, the reason to avoid "test <cond> && test <cond>" spawning
one extra process by using a single "test <cond> -a <cond>" no
longer exists.
Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This reverts commit 4dce7d9b40,
which was originally done to help Windows but was almost
immediately reverted in msysGit, and the codebase kept this
unnecessary divergence for almost two years.
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This reverts commit 23d25e48f5, as it is
broken for users who haven't opted into the new feature of checking
out submodule.*.branch with update mode set to checkout.
Commit 322bb6e12f (add update 'none' flag to disable update of submodule
by default) added the '--checkout' option to "git submodule update" but
forgot to explicitly document it in synopsis, usage string and man page
(It is only mentioned implicitly in the man page). In 23d25e48 (submodule:
explicit local branch creation in module_clone) the synopsis of the man
page was updated, but the "OPTIONS" section of the man page and the usage
string of the git-submodule script still do not mention the '--checkout'
option.
Fix that by documenting this option in usage string and the "OPTIONS"
section of man page too. While at it group the update-mode options into
a single set in the usage string.
Reported-by: Matthijs Kooijman <matthijs@stdin.nl>
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make sure 'submodule update' modes that do not detach HEADs can
be used more pleasantly by checking out a concrete branch when
cloning them to prime the well.
* wk/submodule-on-branch:
Documentation: describe 'submodule update --remote' use case
submodule: explicit local branch creation in module_clone
submodule: document module_clone arguments in comments
submodule: make 'checkout' update_module mode more explicit
The previous code only checked out branches in cmd_add. This commit
moves the branch-checkout logic into module_clone, where it can be
shared by cmd_add and cmd_update. I also update the initial checkout
command to use 'reset' to preserve branches setup during module_clone.
With this change, folks cloning submodules for the first time via:
$ git submodule update ...
will get a local branch instead of a detached HEAD, unless they are
using the default checkout-mode updates. This is a change from the
previous situation where cmd_update always used checkout-mode logic
(regardless of the requested update mode) for updates that triggered
an initial clone, which always resulted in a detached HEAD.
This commit does not change the logic for updates after the initial
clone, which will continue to create detached HEADs for checkout-mode
updates, and integrate remote work with the local HEAD (detached or
not) in other modes.
The motivation for the change is that developers doing local work
inside the submodule are likely to select a non-checkout-mode for
updates so their local work is integrated with upstream work.
Developers who are not doing local submodule work stick with
checkout-mode updates so any apparently local work is blown away
during updates. For example, if upstream rolls back the remote branch
or gitlinked commit to an earlier version, the checkout-mode developer
wants their old submodule checkout to be rolled back as well, instead
of getting a no-op merge/rebase with the rolled-back reference.
By using the update mode to distinguish submodule developers from
black-box submodule consumers, we can setup local branches for the
developers who will want local branches, and stick with detached HEADs
for the developers that don't care.
Testing
=======
In t7406, just-cloned checkouts now update to the gitlinked hash with
'reset', to preserve the local branch for situations where we're not
on a detached HEAD.
I also added explicit tests to t7406 for HEAD attachement after
cloning updates, showing that it depends on their update mode:
* Checkout-mode updates get detached HEADs
* Everyone else gets a local branch, matching the configured
submodule.<name>.branch and defaulting to master.
The 'initial-setup' tag makes it easy to reset the superproject to a
known state, as several earlier tests commit to submodules and commit
the changed gitlinks to the superproject, but don't push the new
submodule commits to the upstream subprojects. This makes it
impossible to checkout the current super master, because it references
submodule commits that don't exist in the upstream subprojects. For a
specific example, see the tests that currently generate the
'two_new_submodule_commits' commits.
Documentation
=============
I updated the docs to describe the 'submodule update' modes in detail.
The old documentation did not distinguish between cloning and
non-cloning updates and lacked clarity on which operations would lead
to detached HEADs, and which would not. The new documentation
addresses these issues while updating the docs to reflect the changes
introduced by this commit's explicit local branch creation in
module_clone.
I also add '--checkout' to the usage summary and group the update-mode
options into a single set.
Signed-off-by: W. Trevor King <wking@tremily.us>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This avoids the current awkwardness of having either '' or 'checkout'
for checkout-mode updates, which makes testing for checkout-mode
updates (or non-checkout-mode updates) easier.
Signed-off-by: W. Trevor King <wking@tremily.us>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"submodule.*.update=checkout", when propagated from .gitmodules to
.git/config, turned into a "submodule.*.update=none", which did not
make much sense.
* fp/submodule-checkout-mode:
git-submodule.sh: 'checkout' is a valid update mode
'checkout' is documented as one of the valid values for the
'submodule.<name>.update' variable, and in a repository with the
variable set to 'checkout', "git submodule update" command does
update using the 'checkout' mode.
However, it has been an accident that the implementation works this
way; any unknown value would trigger the same codepath and update
using the 'checkout' mode.
Explicitly list 'checkout' as one of the known update modes, and
error out when an unknown update mode is used.
Teach the codepath that initializes the configuration variable from
an in-tree .gitmodules that 'checkout' is one of the valid values.
The code since ac1fbbda (submodule: do not copy unknown update mode
from .gitmodules, 2013-12-02) used to treat the value 'checkout' as
unknown and mapped it to 'none', which made little sense. With this
change, 'checkout' specified in .gitmodules will stay to be 'checkout'.
Signed-off-by: Francesco Pretto <ceztko@gmail.com>
Signed-off-by: Signed-off-by: Junio C Hamano <gitster@pobox.com>