Merge branch 'sg/complete-paths'

Command line completion (in contrib/) learned to complete pathnames
for various commands better.

* sg/complete-paths:
  t9902-completion: exercise __git_complete_index_file() directly
  completion: don't return with error from __gitcomp_file_direct()
  completion: fill COMPREPLY directly when completing paths
  completion: improve handling quoted paths in 'git ls-files's output
  completion: remove repeated dirnames with 'awk' during path completion
  t9902-completion: ignore COMPREPLY element order in some tests
  completion: use 'awk' to strip trailing path components
  completion: let 'ls-files' and 'diff-index' filter matching paths
  completion: improve handling quoted paths on the command line
  completion: support completing non-ASCII pathnames
  completion: simplify prefix path component handling during path completion
  completion: move __git_complete_index_file() next to its helpers
  t9902-completion: add tests demonstrating issues with quoted pathnames

3 files changed, 362 insertions, 28 deletions

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 961a0ed76f..1491b7239b 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -94,6 +94,70 @@ __git ()
 		${__git_dir:+--git-dir="$__git_dir"} "$@" 2>/dev/null
 }
 
+# Removes backslash escaping, single quotes and double quotes from a word,
+# stores the result in the variable $dequoted_word.
+# 1: The word to dequote.
+__git_dequote ()
+{
+	local rest="$1" len ch
+
+	dequoted_word=""
+
+	while test -n "$rest"; do
+		len=${#dequoted_word}
+		dequoted_word="$dequoted_word${rest%%[\\\'\"]*}"
+		rest="${rest:$((${#dequoted_word}-$len))}"
+
+		case "${rest:0:1}" in
+		\\)
+			ch="${rest:1:1}"
+			case "$ch" in
+			$'\n')
+				;;
+			*)
+				dequoted_word="$dequoted_word$ch"
+				;;
+			esac
+			rest="${rest:2}"
+			;;
+		\')
+			rest="${rest:1}"
+			len=${#dequoted_word}
+			dequoted_word="$dequoted_word${rest%%\'*}"
+			rest="${rest:$((${#dequoted_word}-$len+1))}"
+			;;
+		\")
+			rest="${rest:1}"
+			while test -n "$rest" ; do
+				len=${#dequoted_word}
+				dequoted_word="$dequoted_word${rest%%[\\\"]*}"
+				rest="${rest:$((${#dequoted_word}-$len))}"
+				case "${rest:0:1}" in
+				\\)
+					ch="${rest:1:1}"
+					case "$ch" in
+					\"|\\|\$|\`)
+						dequoted_word="$dequoted_word$ch"
+						;;
+					$'\n')
+						;;
+					*)
+						dequoted_word="$dequoted_word\\$ch"
+						;;
+					esac
+					rest="${rest:2}"
+					;;
+				\")
+					rest="${rest:1}"
+					break
+					;;
+				esac
+			done
+			;;
+		esac
+	done
+}
+
 # The following function is based on code from:
 #
 #   bash_completion - programmable completion functions for bash 3.2+
@@ -346,6 +410,24 @@ __gitcomp_nl ()
 	__gitcomp_nl_append "$@"
 }
 
+# Fills the COMPREPLY array with prefiltered paths without any additional
+# processing.
+# Callers must take care of providing only paths that match the current path
+# to be completed and adding any prefix path components, if necessary.
+# 1: List of newline-separated matching paths, complete with all prefix
+#    path componens.
+__gitcomp_file_direct ()
+{
+	local IFS=$'\n'
+
+	COMPREPLY=($1)
+
+	# use a hack to enable file mode in bash < 4
+	compopt -o filenames +o nospace 2>/dev/null ||
+	compgen -f /non-existing-dir/ >/dev/null ||
+	true
+}
+
 # Generates completion reply with compgen from newline-separated possible
 # completion filenames.
 # It accepts 1 to 3 arguments:
@@ -365,7 +447,8 @@ __gitcomp_file ()
 
 	# use a hack to enable file mode in bash < 4
 	compopt -o filenames +o nospace 2>/dev/null ||
-	compgen -f /non-existing-dir/ > /dev/null
+	compgen -f /non-existing-dir/ >/dev/null ||
+	true
 }
 
 # Execute 'git ls-files', unless the --committable option is specified, in
@@ -375,10 +458,12 @@ __gitcomp_file ()
 __git_ls_files_helper ()
 {
 	if [ "$2" == "--committable" ]; then
-		__git -C "$1" diff-index --name-only --relative HEAD
+		__git -C "$1" -c core.quotePath=false diff-index \
+			--name-only --relative HEAD -- "${3//\\/\\\\}*"
 	else
 		# NOTE: $2 is not quoted in order to support multiple options
-		__git -C "$1" ls-files --exclude-standard $2
+		__git -C "$1" -c core.quotePath=false ls-files \
+			--exclude-standard $2 -- "${3//\\/\\\\}*"
 	fi
 }
 
@@ -389,12 +474,103 @@ __git_ls_files_helper ()
 #    If provided, only files within the specified directory are listed.
 #    Sub directories are never recursed.  Path must have a trailing
 #    slash.
+# 3: List only paths matching this path component (optional).
 __git_index_files ()
 {
-	local root="${2-.}" file
+	local root="$2" match="$3"
 
-	__git_ls_files_helper "$root" "$1" |
-	cut -f1 -d/ | sort | uniq
+	__git_ls_files_helper "$root" "$1" "$match" |
+	awk -F / -v pfx="${2//\\/\\\\}" '{
+		paths[$1] = 1
+	}
+	END {
+		for (p in paths) {
+			if (substr(p, 1, 1) != "\"") {
+				# No special characters, easy!
+				print pfx p
+				continue
+			}
+
+			# The path is quoted.
+			p = dequote(p)
+			if (p == "")
+				continue
+
+			# Even when a directory name itself does not contain
+			# any special characters, it will still be quoted if
+			# any of its (stripped) trailing path components do.
+			# Because of this we may have seen the same direcory
+			# both quoted and unquoted.
+			if (p in paths)
+				# We have seen the same directory unquoted,
+				# skip it.
+				continue
+			else
+				print pfx p
+		}
+	}
+	function dequote(p,    bs_idx, out, esc, esc_idx, dec) {
+		# Skip opening double quote.
+		p = substr(p, 2)
+
+		# Interpret backslash escape sequences.
+		while ((bs_idx = index(p, "\\")) != 0) {
+			out = out substr(p, 1, bs_idx - 1)
+			esc = substr(p, bs_idx + 1, 1)
+			p = substr(p, bs_idx + 2)
+
+			if ((esc_idx = index("abtvfr\"\\", esc)) != 0) {
+				# C-style one-character escape sequence.
+				out = out substr("\a\b\t\v\f\r\"\\",
+						 esc_idx, 1)
+			} else if (esc == "n") {
+				# Uh-oh, a newline character.
+				# We cant reliably put a pathname
+				# containing a newline into COMPREPLY,
+				# and the newline would create a mess.
+				# Skip this path.
+				return ""
+			} else {
+				# Must be a \nnn octal value, then.
+				dec = esc             * 64 + \
+				      substr(p, 1, 1) * 8  + \
+				      substr(p, 2, 1)
+				out = out sprintf("%c", dec)
+				p = substr(p, 3)
+			}
+		}
+		# Drop closing double quote, if there is one.
+		# (There isnt any if this is a directory, as it was
+		# already stripped with the trailing path components.)
+		if (substr(p, length(p), 1) == "\"")
+			out = out substr(p, 1, length(p) - 1)
+		else
+			out = out p
+
+		return out
+	}'
+}
+
+# __git_complete_index_file requires 1 argument:
+# 1: the options to pass to ls-file
+#
+# The exception is --committable, which finds the files appropriate commit.
+__git_complete_index_file ()
+{
+	local dequoted_word pfx="" cur_
+
+	__git_dequote "$cur"
+
+	case "$dequoted_word" in
+	?*/*)
+		pfx="${dequoted_word%/*}/"
+		cur_="${dequoted_word##*/}"
+		;;
+	*)
+		cur_="$dequoted_word"
+	esac
+
+	__gitcomp_file_direct "$(__git_index_files "$1" "$pfx" "$cur_")"
 }
 
 # Lists branches from the local repository.
@@ -713,26 +889,6 @@ __git_complete_revlist_file ()
 	esac
 }
 
-
-# __git_complete_index_file requires 1 argument:
-# 1: the options to pass to ls-file
-#
-# The exception is --committable, which finds the files appropriate commit.
-__git_complete_index_file ()
-{
-	local pfx="" cur_="$cur"
-
-	case "$cur_" in
-	?*/*)
-		pfx="${cur_%/*}"
-		cur_="${cur_##*/}"
-		pfx="${pfx}/"
-		;;
-	esac
-
-	__gitcomp_file "$(__git_index_files "$1" ${pfx:+"$pfx"})" "$pfx" "$cur_"
-}
-
 __git_complete_file ()
 {
 	__git_complete_revlist_file
@@ -3232,6 +3388,15 @@ if [[ -n ${ZSH_VERSION-} ]]; then
 		compadd -Q -S "${4- }" -p "${2-}" -- ${=1} && _ret=0
 	}
 
+	__gitcomp_file_direct ()
+	{
+		emulate -L zsh
+
+		local IFS=$'\n'
+		compset -P '*[=:]'
+		compadd -Q -f -- ${=1} && _ret=0
+	}
+
 	__gitcomp_file ()
 	{
 		emulate -L zsh
diff --git a/contrib/completion/git-completion.zsh b/contrib/completion/git-completion.zsh
index c3521fbfc4..53cb0f934f 100644
--- a/contrib/completion/git-completion.zsh
+++ b/contrib/completion/git-completion.zsh
@@ -93,6 +93,15 @@ __gitcomp_nl_append ()
 	compadd -Q -S "${4- }" -p "${2-}" -- ${=1} && _ret=0
 }
 
+__gitcomp_file_direct ()
+{
+	emulate -L zsh
+
+	local IFS=$'\n'
+	compset -P '*[=:]'
+	compadd -Q -f -- ${=1} && _ret=0
+}
+
 __gitcomp_file ()
 {
 	emulate -L zsh
diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index 1b34caa1e1..1b6d275254 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -84,10 +84,11 @@ test_completion ()
 	then
 		printf '%s\n' "$2" >expected
 	else
-		sed -e 's/Z$//' >expected
+		sed -e 's/Z$//' |sort >expected
 	fi &&
 	run_completion "$1" &&
-	test_cmp expected out
+	sort out >out_sorted &&
+	test_cmp expected out_sorted
 }
 
 # Test __gitcomp.
@@ -400,6 +401,46 @@ test_expect_success '__gitdir - remote as argument' '
 	test_cmp expected "$actual"
 '
 
+
+test_expect_success '__git_dequote - plain unquoted word' '
+	__git_dequote unquoted-word &&
+	verbose test unquoted-word = "$dequoted_word"
+'
+
+# input:    b\a\c\k\'\\\"s\l\a\s\h\es
+# expected: back'\"slashes
+test_expect_success '__git_dequote - backslash escaped' '
+	__git_dequote "b\a\c\k\\'\''\\\\\\\"s\l\a\s\h\es" &&
+	verbose test "back'\''\\\"slashes" = "$dequoted_word"
+'
+
+# input:    sin'gle\' '"quo'ted
+# expected: single\ "quoted
+test_expect_success '__git_dequote - single quoted' '
+	__git_dequote "'"sin'gle\\\\' '\\\"quo'ted"'" &&
+	verbose test '\''single\ "quoted'\'' = "$dequoted_word"
+'
+
+# input:    dou"ble\\" "\"\quot"ed
+# expected: double\ "\quoted
+test_expect_success '__git_dequote - double quoted' '
+	__git_dequote '\''dou"ble\\" "\"\quot"ed'\'' &&
+	verbose test '\''double\ "\quoted'\'' = "$dequoted_word"
+'
+
+# input: 'open single quote
+test_expect_success '__git_dequote - open single quote' '
+	__git_dequote "'\''open single quote" &&
+	verbose test "open single quote" = "$dequoted_word"
+'
+
+# input: "open double quote
+test_expect_success '__git_dequote - open double quote' '
+	__git_dequote "\"open double quote" &&
+	verbose test "open double quote" = "$dequoted_word"
+'
+
+
 test_expect_success '__gitcomp_direct - puts everything into COMPREPLY as-is' '
 	sed -e "s/Z$//g" >expected <<-EOF &&
 	with-trailing-space Z
@@ -1168,6 +1209,124 @@ test_expect_success 'teardown after ref completion' '
 	git remote remove other
 '
 
+
+test_path_completion ()
+{
+	test $# = 2 || error "bug in the test script: not 2 parameters to test_path_completion"
+
+	local cur="$1" expected="$2"
+	echo "$expected" >expected &&
+	(
+		# In the following tests calling this function we only
+		# care about how __git_complete_index_file() deals with
+		# unusual characters in path names.  By requesting only
+		# untracked files we dont have to bother adding any
+		# paths to the index in those tests.
+		__git_complete_index_file --others &&
+		print_comp
+	) &&
+	test_cmp expected out
+}
+
+test_expect_success 'setup for path completion tests' '
+	mkdir simple-dir \
+	      "spaces in dir" \
+	      árvíztűrő &&
+	touch simple-dir/simple-file \
+	      "spaces in dir/spaces in file" \
+	      "árvíztűrő/Сайн яваарай" &&
+	if test_have_prereq !MINGW &&
+	   mkdir BS\\dir \
+		 '$'separators\034in\035dir'' &&
+	   touch BS\\dir/DQ\"file \
+		 '$'separators\034in\035dir/sep\036in\037file''
+	then
+		test_set_prereq FUNNYNAMES
+	else
+		rm -rf BS\\dir '$'separators\034in\035dir''
+	fi
+'
+
+test_expect_success '__git_complete_index_file - simple' '
+	test_path_completion simple simple-dir &&  # Bash is supposed to
+						   # add the trailing /.
+	test_path_completion simple-dir/simple simple-dir/simple-file
+'
+
+test_expect_success \
+    '__git_complete_index_file - escaped characters on cmdline' '
+	test_path_completion spac "spaces in dir" &&  # Bash will turn this
+						      # into "spaces\ in\ dir"
+	test_path_completion "spaces\\ i" \
+			     "spaces in dir" &&
+	test_path_completion "spaces\\ in\\ dir/s" \
+			     "spaces in dir/spaces in file" &&
+	test_path_completion "spaces\\ in\\ dir/spaces\\ i" \
+			     "spaces in dir/spaces in file"
+'
+
+test_expect_success \
+    '__git_complete_index_file - quoted characters on cmdline' '
+	# Testing with an opening but without a corresponding closing
+	# double quote is important.
+	test_path_completion \"spac "spaces in dir" &&
+	test_path_completion "\"spaces i" \
+			     "spaces in dir" &&
+	test_path_completion "\"spaces in dir/s" \
+			     "spaces in dir/spaces in file" &&
+	test_path_completion "\"spaces in dir/spaces i" \
+			     "spaces in dir/spaces in file"
+'
+
+test_expect_success '__git_complete_index_file - UTF-8 in ls-files output' '
+	test_path_completion á árvíztűrő &&
+	test_path_completion árvíztűrő/С "árvíztűrő/Сайн яваарай"
+'
+
+test_expect_success FUNNYNAMES \
+    '__git_complete_index_file - C-style escapes in ls-files output' '
+	test_path_completion BS \
+			     BS\\dir &&
+	test_path_completion BS\\\\d \
+			     BS\\dir &&
+	test_path_completion BS\\\\dir/DQ \
+			     BS\\dir/DQ\"file &&
+	test_path_completion BS\\\\dir/DQ\\\"f \
+			     BS\\dir/DQ\"file
+'
+
+test_expect_success FUNNYNAMES \
+    '__git_complete_index_file - \nnn-escaped characters in ls-files output' '
+	test_path_completion sep '$'separators\034in\035dir'' &&
+	test_path_completion '$'separators\034i'' \
+			     '$'separators\034in\035dir'' &&
+	test_path_completion '$'separators\034in\035dir/sep'' \
+			     '$'separators\034in\035dir/sep\036in\037file'' &&
+	test_path_completion '$'separators\034in\035dir/sep\036i'' \
+			     '$'separators\034in\035dir/sep\036in\037file''
+'
+
+test_expect_success FUNNYNAMES \
+    '__git_complete_index_file - removing repeated quoted path components' '
+	test_when_finished rm -r repeated-quoted &&
+	mkdir repeated-quoted &&      # A directory whose name in itself
+				      # would not be quoted ...
+	>repeated-quoted/0-file &&
+	>repeated-quoted/1\"file &&   # ... but here the file makes the
+				      # dirname quoted ...
+	>repeated-quoted/2-file &&
+	>repeated-quoted/3\"file &&   # ... and here, too.
+
+	# Still, we shold only list the directory name only once.
+	test_path_completion repeated repeated-quoted
+'
+
+test_expect_success 'teardown after path completion tests' '
+	rm -rf simple-dir "spaces in dir" árvíztűrő \
+	       BS\\dir '$'separators\034in\035dir''
+'
+
+
 test_expect_success '__git_get_config_variables' '
 	cat >expect <<-EOF &&
 	name-1
@@ -1365,6 +1524,7 @@ test_expect_success 'complete files' '
 
 	echo "expected" > .gitignore &&
 	echo "out" >> .gitignore &&
+	echo "out_sorted" >> .gitignore &&
 
 	git add .gitignore &&
 	test_completion "git commit " ".gitignore" &&