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8 commits

Author SHA1 Message Date
Derrick Stolee e9de487aa3 sparse-checkout: sanitize for nested folders
If a user provides folders A/ and A/B/ for inclusion in a cone-mode
sparse-checkout file, the parsing logic will notice that A/ appears
both as a "parent" type pattern and as a "recursive" type pattern.
This is unexpected and hence will complain via a warning and revert
to the old logic for checking sparse-checkout patterns.

Prevent this from happening accidentally by sanitizing the folders
for this type of inclusion in the 'git sparse-checkout' builtin.
This happens in two ways:

1. Do not include any parent patterns that also appear as recursive
   patterns.

2. Do not include any recursive patterns deeper than other recursive
   patterns.

In order to minimize duplicate code for scanning parents, create
hashmap_contains_parent() method. It takes a strbuf buffer to
avoid reallocating a buffer when calling in a tight loop.

Helped-by: Eric Wong <e@80x24.org>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:44 +09:00
Derrick Stolee af09ce24a9 sparse-checkout: init and set in cone mode
To make the cone pattern set easy to use, update the behavior of
'git sparse-checkout (init|set)'.

Add '--cone' flag to 'git sparse-checkout init' to set the config
option 'core.sparseCheckoutCone=true'.

When running 'git sparse-checkout set' in cone mode, a user only
needs to supply a list of recursive folder matches. Git will
automatically add the necessary parent matches for the leading
directories.

When testing 'git sparse-checkout set' in cone mode, check the
error stream to ensure we do not see any errors. Specifically,
we want to avoid the warning that the patterns do not match
the cone-mode patterns.

Helped-by: Eric Wong <e@80x24.org>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:44 +09:00
Derrick Stolee 72918c1ad9 sparse-checkout: create 'disable' subcommand
The instructions for disabling a sparse-checkout to a full
working directory are complicated and non-intuitive. Add a
subcommand, 'git sparse-checkout disable', to perform those
steps for the user.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:44 +09:00
Derrick Stolee 7bffca95ea sparse-checkout: add '--stdin' option to set subcommand
The 'git sparse-checkout set' subcommand takes a list of patterns
and places them in the sparse-checkout file. Then, it updates the
working directory to match those patterns. For a large list of
patterns, the command-line call can get very cumbersome.

Add a '--stdin' option to instead read patterns over standard in.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:44 +09:00
Derrick Stolee f6039a9423 sparse-checkout: 'set' subcommand
The 'git sparse-checkout set' subcommand takes a list of patterns
as arguments and writes them to the sparse-checkout file. Then, it
updates the working directory using 'git read-tree -mu HEAD'.

The 'set' subcommand will replace the entire contents of the
sparse-checkout file. The write_patterns_and_update() method is
extracted from cmd_sparse_checkout() to make it easier to implement
'add' and/or 'remove' subcommands in the future.

If the core.sparseCheckout config setting is disabled, then enable
the config setting in the worktree config. If we set the config
this way and the sparse-checkout fails, then re-disable the config
setting.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:43 +09:00
Derrick Stolee d89f09c828 clone: add --sparse mode
When someone wants to clone a large repository, but plans to work
using a sparse-checkout file, they either need to do a full
checkout first and then reduce the patterns they included, or
clone with --no-checkout, set up their patterns, and then run
a checkout manually. This requires knowing a lot about the repo
shape and how sparse-checkout works.

Add a new '--sparse' option to 'git clone' that initializes the
sparse-checkout file to include the following patterns:

	/*
	!/*/

These patterns include every file in the root directory, but
no directories. This allows a repo to include files like a
README or a bootstrapping script to grow enlistments from that
point.

During the 'git sparse-checkout init' call, we must first look
to see if HEAD is valid, since 'git clone' does not have a valid
HEAD at the point where it initializes the sparse-checkout. The
following checkout within the clone command will create the HEAD
ref and update the working directory correctly.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:43 +09:00
Derrick Stolee bab3c35908 sparse-checkout: create 'init' subcommand
Getting started with a sparse-checkout file can be daunting. Help
users start their sparse enlistment using 'git sparse-checkout init'.
This will set 'core.sparseCheckout=true' in their config, write
an initial set of patterns to the sparse-checkout file, and update
their working directory.

Make sure to use the `extensions.worktreeConfig` setting and write
the sparse checkout config to the worktree-specific config file.
This avoids confusing interactions with other worktrees.

The use of running another process for 'git read-tree' is sub-
optimal. This will be removed in a later change.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:43 +09:00
Derrick Stolee 94c0956b60 sparse-checkout: create builtin with 'list' subcommand
The sparse-checkout feature is mostly hidden to users, as its
only documentation is supplementary information in the docs for
'git read-tree'. In addition, users need to know how to edit the
.git/info/sparse-checkout file with the right patterns, then run
the appropriate 'git read-tree -mu HEAD' command. Keeping the
working directory in sync with the sparse-checkout file requires
care.

Begin an effort to make the sparse-checkout feature a porcelain
feature by creating a new 'git sparse-checkout' builtin. This
builtin will be the preferred mechanism for manipulating the
sparse-checkout file and syncing the working directory.

The documentation provided is adapted from the "git read-tree"
documentation with a few edits for clarity in the new context.
Extra sections are added to hint toward a future change to
a more restricted pattern set.

Helped-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:43 +09:00