[PATCH v6 0/3] completion: sparse-checkout updates

This change updates custom tab completion for the sparse-checkout command. Specifically, it corrects the following issues with the current method:

 1. git sparse-checkout <TAB> results in an incomplete list of subcommands
    (it is missing reapply and add).
 2. Options for subcommands are not tab-completable.
 3. git sparse-checkout set <TAB> and git sparse-checkout add <TAB> show
    both file names and directory names. While this may be a less surprising
    behavior for non-cone mode, we want to only show directories in cone
    mode.

The first commit in this series is an intermediate step that fixes issues 1 and 2 above and introduces a simple fix for issue 3 with some performance and unusual character-related caveats. The next commit adds a new __gitcomp_directories method that fixes the performance-related caveat from the first commit by completing just a single level of directories. The final commit modifies __gitcomp_directories to handle unusual characters in directory names.

Changes since V5 ================

 * Fix incorrect conditional that was causing failure of non-cone mode test
   (and causing 'seen' CI to fail).
 * Remove __git_comp_directories indentation changes between the second and
   third commits.

Changes since V4 ================

 * Clarify that completing on files and directories is a less-surprising
   behavior in non-cone mode (rather than definitely the correct behavior)
   in commit message and cover letter.
 * Add explicit --no-cone to non-cone mode sparse-checkout completion test.
 * Replace use of __git_complete_index_file with a new version of
   __gitcomp_directories that is able to handle unusual characters.
 * Ensure that users running git sparse-checkout set --cone get cone
   mode-style completion whether or not they already have the cone mode
   config set.
 * Refactor creation of sparse-checkout test repo into a sparse-checkout
   setup test.

Changes since V3 ================

 * Update commit descriptions to begin with completion instead of
   sparse-checkout.
 * Remove explicit completion of --help, as this is inconsistent with the
   rest of the completion script.
 * Use __gitcomp_builtin to auto-complete subcommand options (and remove
   option completion test from previous iterations, as it is no longer
   necessary).
 * Use __git_complete_index_file helper function in place of __gitcomp
   "$(git ls-tree -d -r HEAD --name-only).
 * If in cone-mode sparse checkout, only show directory completions. If in
   non-cone mode sparse checkout show both files and directories.

Changes since V2 ================

 * Change use of $prev to $subcommand in _git_sparse_checkout() method in
   git-completion.bash.
 * State explicitly that directory completion applies in both cone and
   non-cone mode in 'sparse-checkout: custom tab completion' commit
 * Add new patch with __gitcomp_directories method to improve performance by
   only outputting directories at the current level.

Changes since V1 ================

 * Rebase onto en/sparse-checkout-set.
 * Add subcommand options (including --no-cone) for set and reapply.
 * Extend 'sparse-checkout completes subcommand options' test to validate
   new set/reapply subcommand options.
 * No longer set index.sparse to false in 'sparse-checkout completes
   directory names' test.
 * Refactor creation of sparse-checkout repo into a setup test.

Thanks, Lessley

Lessley Dennington (3):
  completion: address sparse-checkout issues
  completion: improve sparse-checkout cone mode directory completion
  completion: handle unusual characters for sparse-checkout

 contrib/completion/git-completion.bash |  44 ++++++++--
 t/t9902-completion.sh                  | 117 +++++++++++++++++++++++++
 2 files changed, 153 insertions(+), 8 deletions(-)

base-commit: dfac9b609f86cd4f6ce896df9e1172d2a02cde48
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1108%2Fldennington%2Fsparse-checkout-bash-completion-v6
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1108/ldennington/sparse-checkout-bash-completion-v6
Pull-Request: https://github.com/gitgitgadget/git/pull/1108

Range-diff vs v5:

 1:  a1c46c763fd ! 1:  23390000dd3 completion: address sparse-checkout issues
     @@ contrib/completion/git-completion.bash: _git_sparse_checkout ()
      +		__gitcomp_builtin sparse-checkout_$subcommand "" "--"
       		;;
      +	set,*|add,*)
     -+		if [ $(__git config core.sparseCheckoutCone) ] ||
     -+		[ "$(__git_find_on_cmdline --cone)" ]; then
     ++		if [ "$(__git config core.sparseCheckoutCone)" == "true" ] ||
     ++		[ -n "$(__git_find_on_cmdline --cone)" ]; then
      +			__gitcomp "$(git ls-tree -d -r HEAD --name-only)"
      +		fi
       	esac
 2:  5b8d53402ae ! 2:  10a190ce6a1 completion: improve sparse-checkout cone mode directory completion
     @@ contrib/completion/git-completion.bash: _git_show_branch ()
       
      +__gitcomp_directories ()
      +{
     -+     local _tmp_dir _tmp_completions
     ++	local _tmp_dir _tmp_completions
      +
     -+     # Get the directory of the current token; this differs from dirname
     -+     # in that it keeps up to the final trailing slash.  If no slash found
     -+     # that's fine too.
     -+     [[ "$cur" =~ .*/ ]]
     -+     _tmp_dir=$BASH_REMATCH
     ++	# Get the directory of the current token; this differs from dirname
     ++	# in that it keeps up to the final trailing slash.  If no slash found
     ++	# that's fine too.
     ++	[[ "$cur" =~ .*/ ]]
     ++	_tmp_dir=$BASH_REMATCH
      +
     -+     # Find possible directory completions, adding trailing '/' characters
     -+     _tmp_completions="$(git ls-tree -d --name-only HEAD $_tmp_dir |
     -+         sed -e s%$%/%)"
     ++	# Find possible directory completions, adding trailing '/' characters
     ++	_tmp_completions="$(git ls-tree -d --name-only HEAD $_tmp_dir |
     ++		sed -e s%$%/%)"
      +
     -+     if [[ -n "$_tmp_completions" ]]; then
     -+         # There were some directory completions, so find ones that
     -+         # start with "$cur", the current token, and put those in COMPREPLY
     -+         local i=0 c IFS=$' \t\n'
     -+         for c in $_tmp_completions; do
     -+             if [[ $c == "$cur"* ]]; then
     -+                 COMPREPLY+=("$c")
     -+             fi
     -+         done
     -+     elif [[ "$cur" =~ /$ ]]; then
     -+         # No possible further completions any deeper, so assume we're at
     -+         # a leaf directory and just consider it complete
     -+         __gitcomp_direct_append "$cur "
     -+     fi
     ++	if [[ -n "$_tmp_completions" ]]; then
     ++		# There were some directory completions, so find ones that
     ++		# start with "$cur", the current token, and put those in COMPREPLY
     ++		local i=0 c IFS=$' \t\n'
     ++		for c in $_tmp_completions; do
     ++		if [[ $c == "$cur"* ]]; then
     ++			COMPREPLY+=("$c")
     ++		fi
     ++		done
     ++	elif [[ "$cur" =~ /$ ]]; then
     ++		# No possible further completions any deeper, so assume we're at
     ++		# a leaf directory and just consider it complete
     ++		__gitcomp_direct_append "$cur "
     ++	fi
      +}
      +
       _git_sparse_checkout ()
     @@ contrib/completion/git-completion.bash: _git_show_branch ()
       	local subcommands="list init set disable add reapply"
      @@ contrib/completion/git-completion.bash: _git_sparse_checkout ()
       	set,*|add,*)
     - 		if [ $(__git config core.sparseCheckoutCone) ] ||
     - 		[ "$(__git_find_on_cmdline --cone)" ]; then
     + 		if [ "$(__git config core.sparseCheckoutCone)" == "true" ] ||
     + 		[ -n "$(__git_find_on_cmdline --cone)" ]; then
      -			__gitcomp "$(git ls-tree -d -r HEAD --name-only)"
      +			__gitcomp_directories
       		fi
 3:  ddf5e583dd7 ! 3:  e805dbb58cc completion: handle unusual characters for sparse-checkout
     @@ contrib/completion/git-completion.bash: _git_show_branch ()
       
       __gitcomp_directories ()
       {
     --     local _tmp_dir _tmp_completions
     --
     --     # Get the directory of the current token; this differs from dirname
     --     # in that it keeps up to the final trailing slash.  If no slash found
     --     # that's fine too.
     --     [[ "$cur" =~ .*/ ]]
     --     _tmp_dir=$BASH_REMATCH
     --
     --     # Find possible directory completions, adding trailing '/' characters
     --     _tmp_completions="$(git ls-tree -d --name-only HEAD $_tmp_dir |
     --         sed -e s%$%/%)"
     --
     --     if [[ -n "$_tmp_completions" ]]; then
     --         # There were some directory completions, so find ones that
     --         # start with "$cur", the current token, and put those in COMPREPLY
     --         local i=0 c IFS=$' \t\n'
     --         for c in $_tmp_completions; do
     --             if [[ $c == "$cur"* ]]; then
     --                 COMPREPLY+=("$c")
     --             fi
     --         done
     --     elif [[ "$cur" =~ /$ ]]; then
     --         # No possible further completions any deeper, so assume we're at
     --         # a leaf directory and just consider it complete
     --         __gitcomp_direct_append "$cur "
     --     fi
     +-	local _tmp_dir _tmp_completions
      +	local _tmp_dir _tmp_completions _found=0
     -+
     -+	# Get the directory of the current token; this differs from dirname
     -+	# in that it keeps up to the final trailing slash.  If no slash found
     -+	# that's fine too.
     -+	[[ "$cur" =~ .*/ ]]
     -+	_tmp_dir=$BASH_REMATCH
     -+
     + 
     + 	# Get the directory of the current token; this differs from dirname
     + 	# in that it keeps up to the final trailing slash.  If no slash found
     +@@ contrib/completion/git-completion.bash: __gitcomp_directories ()
     + 	[[ "$cur" =~ .*/ ]]
     + 	_tmp_dir=$BASH_REMATCH
     + 
     +-	# Find possible directory completions, adding trailing '/' characters
     +-	_tmp_completions="$(git ls-tree -d --name-only HEAD $_tmp_dir |
     +-		sed -e s%$%/%)"
     +-
     +-	if [[ -n "$_tmp_completions" ]]; then
     +-		# There were some directory completions, so find ones that
     +-		# start with "$cur", the current token, and put those in COMPREPLY
     +-		local i=0 c IFS=$' \t\n'
     +-		for c in $_tmp_completions; do
      +	# Find possible directory completions, adding trailing '/' characters,
      +	# de-quoting, and handling unusual characters.
      +	while IFS= read -r -d $'\0' c ; do
      +		# If there are directory completions, find ones that start
      +		# with "$cur", the current token, and put those in COMPREPLY
     -+		if [[ $c == "$cur"* ]]; then
     + 		if [[ $c == "$cur"* ]]; then
     +-			COMPREPLY+=("$c")
      +			COMPREPLY+=("$c/")
      +			_found=1
     -+		fi
     + 		fi
     +-		done
     +-	elif [[ "$cur" =~ /$ ]]; then
      +	done < <(git ls-tree -z -d --name-only HEAD $_tmp_dir)
      +
      +	if [[ $_found == 0 ]] && [[ "$cur" =~ /$ ]]; then
     -+		# No possible further completions any deeper, so assume we're at
     -+		# a leaf directory and just consider it complete
     -+		__gitcomp_direct_append "$cur "
     -+	fi
     - }
     - 
     - _git_sparse_checkout ()
     + 		# No possible further completions any deeper, so assume we're at
     + 		# a leaf directory and just consider it complete
     + 		__gitcomp_direct_append "$cur "
      
       ## t/t9902-completion.sh ##
      @@ t/t9902-completion.sh: test_expect_success 'cone mode sparse-checkout completes directory names' '