Merge branch 'sg/completion-refs-speedup'

The refs completion for large number of refs has been sped up,
partly by giving up disambiguating ambiguous refs and partly by
eliminating most of the shell processing between 'git for-each-ref'
and 'ls-remote' and Bash's completion facility.

* sg/completion-refs-speedup:
  completion: speed up branch and tag completion
  completion: fill COMPREPLY directly when completing fetch refspecs
  completion: fill COMPREPLY directly when completing refs
  completion: let 'for-each-ref' sort remote branches for 'checkout' DWIMery
  completion: let 'for-each-ref' filter remote branches for 'checkout' DWIMery
  completion: let 'for-each-ref' strip the remote name from remote branches
  completion: let 'for-each-ref' and 'ls-remote' filter matching refs
  completion: don't disambiguate short refs
  completion: don't disambiguate tags and branches
  completion: support excluding full refs
  completion: support completing fully qualified non-fast-forward refspecs
  completion: support completing full refs after '--option=refs/<TAB>'
  completion: wrap __git_refs() for better option parsing
  completion: remove redundant __gitcomp_nl() options from _git_commit()

2 files changed, 190 insertions, 71 deletions

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index fc32286a43..380f755b9f 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -213,6 +213,20 @@ _get_comp_words_by_ref ()
 }
 fi
 
+# Fills the COMPREPLY array with prefiltered words without any additional
+# processing.
+# Callers must take care of providing only words that match the current word
+# to be completed and adding any prefix and/or suffix (trailing space!), if
+# necessary.
+# 1: List of newline-separated matching completion words, complete with
+#    prefix and suffix.
+__gitcomp_direct ()
+{
+	local IFS=$'\n'
+
+	COMPREPLY=($1)
+}
+
 __gitcompappend ()
 {
 	local x i=${#COMPREPLY[@]}
@@ -338,14 +352,27 @@ __git_index_files ()
 	done | sort | uniq
 }
 
+# Lists branches from the local repository.
+# 1: A prefix to be added to each listed branch (optional).
+# 2: List only branches matching this word (optional; list all branches if
+#    unset or empty).
+# 3: A suffix to be appended to each listed branch (optional).
 __git_heads ()
 {
-	__git for-each-ref --format='%(refname:short)' refs/heads
+	local pfx="${1-}" cur_="${2-}" sfx="${3-}"
+
+	__git for-each-ref --format="${pfx//\%/%%}%(refname:strip=2)$sfx" \
+			"refs/heads/$cur_*" "refs/heads/$cur_*/**"
 }
 
+# Lists tags from the local repository.
+# Accepts the same positional parameters as __git_heads() above.
 __git_tags ()
 {
-	__git for-each-ref --format='%(refname:short)' refs/tags
+	local pfx="${1-}" cur_="${2-}" sfx="${3-}"
+
+	__git for-each-ref --format="${pfx//\%/%%}%(refname:strip=2)$sfx" \
+			"refs/tags/$cur_*" "refs/tags/$cur_*/**"
 }
 
 # Lists refs from the local (by default) or from a remote repository.
@@ -354,11 +381,21 @@ __git_tags ()
 #    Can be the name of a configured remote, a path, or a URL.
 # 2: In addition to local refs, list unique branches from refs/remotes/ for
 #    'git checkout's tracking DWIMery (optional; ignored, if set but empty).
+# 3: A prefix to be added to each listed ref (optional).
+# 4: List only refs matching this word (optional; list all refs if unset or
+#    empty).
+# 5: A suffix to be appended to each listed ref (optional; ignored, if set
+#    but empty).
+#
+# Use __git_complete_refs() instead.
 __git_refs ()
 {
 	local i hash dir track="${2-}"
 	local list_refs_from=path remote="${1-}"
-	local format refs pfx
+	local format refs
+	local pfx="${3-}" cur_="${4-$cur}" sfx="${5-}"
+	local match="${4-}"
+	local fer_pfx="${pfx//\%/%%}" # "escape" for-each-ref format specifiers
 
 	__git_find_repo_path
 	dir="$__git_repo_path"
@@ -382,63 +419,78 @@ __git_refs ()
 	fi
 
 	if [ "$list_refs_from" = path ]; then
-		case "$cur" in
+		if [[ "$cur_" == ^* ]]; then
+			pfx="$pfx^"
+			fer_pfx="$fer_pfx^"
+			cur_=${cur_#^}
+			match=${match#^}
+		fi
+		case "$cur_" in
 		refs|refs/*)
 			format="refname"
-			refs="${cur%/*}"
+			refs=("$match*" "$match*/**")
 			track=""
 			;;
 		*)
-			[[ "$cur" == ^* ]] && pfx="^"
 			for i in HEAD FETCH_HEAD ORIG_HEAD MERGE_HEAD; do
-				if [ -e "$dir/$i" ]; then echo $pfx$i; fi
+				case "$i" in
+				$match*)
+					if [ -e "$dir/$i" ]; then
+						echo "$pfx$i$sfx"
+					fi
+					;;
+				esac
 			done
-			format="refname:short"
-			refs="refs/tags refs/heads refs/remotes"
+			format="refname:strip=2"
+			refs=("refs/tags/$match*" "refs/tags/$match*/**"
+				"refs/heads/$match*" "refs/heads/$match*/**"
+				"refs/remotes/$match*" "refs/remotes/$match*/**")
 			;;
 		esac
-		__git_dir="$dir" __git for-each-ref --format="$pfx%($format)" \
-			$refs
+		__git_dir="$dir" __git for-each-ref --format="$fer_pfx%($format)$sfx" \
+			"${refs[@]}"
 		if [ -n "$track" ]; then
 			# employ the heuristic used by git checkout
 			# Try to find a remote branch that matches the completion word
 			# but only output if the branch name is unique
-			local ref entry
-			__git for-each-ref --shell --format="ref=%(refname:short)" \
-				"refs/remotes/" | \
-			while read -r entry; do
-				eval "$entry"
-				ref="${ref#*/}"
-				if [[ "$ref" == "$cur"* ]]; then
-					echo "$ref"
-				fi
-			done | sort | uniq -u
+			__git for-each-ref --format="$fer_pfx%(refname:strip=3)$sfx" \
+				--sort="refname:strip=3" \
+				"refs/remotes/*/$match*" "refs/remotes/*/$match*/**" | \
+			uniq -u
 		fi
 		return
 	fi
-	case "$cur" in
+	case "$cur_" in
 	refs|refs/*)
-		__git ls-remote "$remote" "$cur*" | \
+		__git ls-remote "$remote" "$match*" | \
 		while read -r hash i; do
 			case "$i" in
 			*^{}) ;;
-			*) echo "$i" ;;
+			*) echo "$pfx$i$sfx" ;;
 			esac
 		done
 		;;
 	*)
 		if [ "$list_refs_from" = remote ]; then
-			echo "HEAD"
-			__git for-each-ref --format="%(refname:short)" \
-				"refs/remotes/$remote/" | sed -e "s#^$remote/##"
+			case "HEAD" in
+			$match*)	echo "${pfx}HEAD$sfx" ;;
+			esac
+			__git for-each-ref --format="$fer_pfx%(refname:strip=3)$sfx" \
+				"refs/remotes/$remote/$match*" \
+				"refs/remotes/$remote/$match*/**"
 		else
-			__git ls-remote "$remote" HEAD \
-				"refs/tags/*" "refs/heads/*" "refs/remotes/*" |
+			local query_symref
+			case "HEAD" in
+			$match*)	query_symref="HEAD" ;;
+			esac
+			__git ls-remote "$remote" $query_symref \
+				"refs/tags/$match*" "refs/heads/$match*" \
+				"refs/remotes/$match*" |
 			while read -r hash i; do
 				case "$i" in
 				*^{})	;;
-				refs/*)	echo "${i#refs/*/}" ;;
-				*)	echo "$i" ;;  # symbolic refs
+				refs/*)	echo "$pfx${i#refs/*/}$sfx" ;;
+				*)	echo "$pfx$i$sfx" ;;  # symbolic refs
 				esac
 			done
 		fi
@@ -446,7 +498,38 @@ __git_refs ()
 	esac
 }
 
+# Completes refs, short and long, local and remote, symbolic and pseudo.
+#
+# Usage: __git_complete_refs [<option>]...
+# --remote=<remote>: The remote to list refs from, can be the name of a
+#                    configured remote, a path, or a URL.
+# --track: List unique remote branches for 'git checkout's tracking DWIMery.
+# --pfx=<prefix>: A prefix to be added to each ref.
+# --cur=<word>: The current ref to be completed.  Defaults to the current
+#               word to be completed.
+# --sfx=<suffix>: A suffix to be appended to each ref instead of the default
+#                 space.
+__git_complete_refs ()
+{
+	local remote track pfx cur_="$cur" sfx=" "
+
+	while test $# != 0; do
+		case "$1" in
+		--remote=*)	remote="${1##--remote=}" ;;
+		--track)	track="yes" ;;
+		--pfx=*)	pfx="${1##--pfx=}" ;;
+		--cur=*)	cur_="${1##--cur=}" ;;
+		--sfx=*)	sfx="${1##--sfx=}" ;;
+		*)		return 1 ;;
+		esac
+		shift
+	done
+
+	__gitcomp_direct "$(__git_refs "$remote" "$track" "$pfx" "$cur_" "$sfx")"
+}
+
 # __git_refs2 requires 1 argument (to pass to __git_refs)
+# Deprecated: use __git_complete_fetch_refspecs() instead.
 __git_refs2 ()
 {
 	local i
@@ -455,6 +538,24 @@ __git_refs2 ()
 	done
 }
 
+# Completes refspecs for fetching from a remote repository.
+# 1: The remote repository.
+# 2: A prefix to be added to each listed refspec (optional).
+# 3: The ref to be completed as a refspec instead of the current word to be
+#    completed (optional)
+# 4: A suffix to be appended to each listed refspec instead of the default
+#    space (optional).
+__git_complete_fetch_refspecs ()
+{
+	local i remote="$1" pfx="${2-}" cur_="${3-$cur}" sfx="${4- }"
+
+	__gitcomp_direct "$(
+		for i in $(__git_refs "$remote" "" "" "$cur_") ; do
+			echo "$pfx$i:$i$sfx"
+		done
+		)"
+}
+
 # __git_refs_remotes requires 1 argument (to pass to ls-remote)
 __git_refs_remotes ()
 {
@@ -554,15 +655,15 @@ __git_complete_revlist_file ()
 	*...*)
 		pfx="${cur_%...*}..."
 		cur_="${cur_#*...}"
-		__gitcomp_nl "$(__git_refs)" "$pfx" "$cur_"
+		__git_complete_refs --pfx="$pfx" --cur="$cur_"
 		;;
 	*..*)
 		pfx="${cur_%..*}.."
 		cur_="${cur_#*..}"
-		__gitcomp_nl "$(__git_refs)" "$pfx" "$cur_"
+		__git_complete_refs --pfx="$pfx" --cur="$cur_"
 		;;
 	*)
-		__gitcomp_nl "$(__git_refs)"
+		__git_complete_refs
 		;;
 	esac
 }
@@ -647,23 +748,23 @@ __git_complete_remote_or_refspec ()
 	case "$cmd" in
 	fetch)
 		if [ $lhs = 1 ]; then
-			__gitcomp_nl "$(__git_refs2 "$remote")" "$pfx" "$cur_"
+			__git_complete_fetch_refspecs "$remote" "$pfx" "$cur_"
 		else
-			__gitcomp_nl "$(__git_refs)" "$pfx" "$cur_"
+			__git_complete_refs --pfx="$pfx" --cur="$cur_"
 		fi
 		;;
 	pull|remote)
 		if [ $lhs = 1 ]; then
-			__gitcomp_nl "$(__git_refs "$remote")" "$pfx" "$cur_"
+			__git_complete_refs --remote="$remote" --pfx="$pfx" --cur="$cur_"
 		else
-			__gitcomp_nl "$(__git_refs)" "$pfx" "$cur_"
+			__git_complete_refs --pfx="$pfx" --cur="$cur_"
 		fi
 		;;
 	push)
 		if [ $lhs = 1 ]; then
-			__gitcomp_nl "$(__git_refs)" "$pfx" "$cur_"
+			__git_complete_refs --pfx="$pfx" --cur="$cur_"
 		else
-			__gitcomp_nl "$(__git_refs "$remote")" "$pfx" "$cur_"
+			__git_complete_refs --remote="$remote" --pfx="$pfx" --cur="$cur_"
 		fi
 		;;
 	esac
@@ -1066,7 +1167,7 @@ _git_bisect ()
 
 	case "$subcommand" in
 	bad|good|reset|skip|start)
-		__gitcomp_nl "$(__git_refs)"
+		__git_complete_refs
 		;;
 	*)
 		;;
@@ -1088,7 +1189,7 @@ _git_branch ()
 
 	case "$cur" in
 	--set-upstream-to=*)
-		__gitcomp_nl "$(__git_refs)" "" "${cur##--set-upstream-to=}"
+		__git_complete_refs --cur="${cur##--set-upstream-to=}"
 		;;
 	--*)
 		__gitcomp "
@@ -1101,9 +1202,9 @@ _git_branch ()
 		;;
 	*)
 		if [ $only_local_ref = "y" -a $has_r = "n" ]; then
-			__gitcomp_nl "$(__git_heads)"
+			__gitcomp_direct "$(__git_heads "" "$cur" " ")"
 		else
-			__gitcomp_nl "$(__git_refs)"
+			__git_complete_refs
 		fi
 		;;
 	esac
@@ -1146,18 +1247,18 @@ _git_checkout ()
 	*)
 		# check if --track, --no-track, or --no-guess was specified
 		# if so, disable DWIM mode
-		local flags="--track --no-track --no-guess" track=1
+		local flags="--track --no-track --no-guess" track_opt="--track"
 		if [ -n "$(__git_find_on_cmdline "$flags")" ]; then
-			track=''
+			track_opt=''
 		fi
-		__gitcomp_nl "$(__git_refs '' $track)"
+		__git_complete_refs $track_opt
 		;;
 	esac
 }
 
 _git_cherry ()
 {
-	__gitcomp_nl "$(__git_refs)"
+	__git_complete_refs
 }
 
 _git_cherry_pick ()
@@ -1172,7 +1273,7 @@ _git_cherry_pick ()
 		__gitcomp "--edit --no-commit --signoff --strategy= --mainline"
 		;;
 	*)
-		__gitcomp_nl "$(__git_refs)"
+		__git_complete_refs
 		;;
 	esac
 }
@@ -1224,7 +1325,7 @@ _git_commit ()
 {
 	case "$prev" in
 	-c|-C)
-		__gitcomp_nl "$(__git_refs)" "" "${cur}"
+		__git_complete_refs
 		return
 		;;
 	esac
@@ -1237,7 +1338,7 @@ _git_commit ()
 		;;
 	--reuse-message=*|--reedit-message=*|\
 	--fixup=*|--squash=*)
-		__gitcomp_nl "$(__git_refs)" "" "${cur#*=}"
+		__git_complete_refs --cur="${cur#*=}"
 		return
 		;;
 	--untracked-files=*)
@@ -1277,7 +1378,7 @@ _git_describe ()
 			"
 		return
 	esac
-	__gitcomp_nl "$(__git_refs)"
+	__git_complete_refs
 }
 
 __git_diff_algorithms="myers minimal patience histogram"
@@ -1466,7 +1567,7 @@ _git_grep ()
 		;;
 	esac
 
-	__gitcomp_nl "$(__git_refs)"
+	__git_complete_refs
 }
 
 _git_help ()
@@ -1640,7 +1741,7 @@ _git_merge ()
 			--rerere-autoupdate --no-rerere-autoupdate --abort --continue"
 		return
 	esac
-	__gitcomp_nl "$(__git_refs)"
+	__git_complete_refs
 }
 
 _git_mergetool ()
@@ -1665,7 +1766,7 @@ _git_merge_base ()
 		return
 		;;
 	esac
-	__gitcomp_nl "$(__git_refs)"
+	__git_complete_refs
 }
 
 _git_mv ()
@@ -1703,7 +1804,7 @@ _git_notes ()
 	,*)
 		case "$prev" in
 		--ref)
-			__gitcomp_nl "$(__git_refs)"
+			__git_complete_refs
 			;;
 		*)
 			__gitcomp "$subcommands --ref"
@@ -1712,7 +1813,7 @@ _git_notes ()
 		;;
 	add,--reuse-message=*|append,--reuse-message=*|\
 	add,--reedit-message=*|append,--reedit-message=*)
-		__gitcomp_nl "$(__git_refs)" "" "${cur#*=}"
+		__git_complete_refs --cur="${cur#*=}"
 		;;
 	add,--*|append,--*)
 		__gitcomp '--file= --message= --reedit-message=
@@ -1731,7 +1832,7 @@ _git_notes ()
 		-m|-F)
 			;;
 		*)
-			__gitcomp_nl "$(__git_refs)"
+			__git_complete_refs
 			;;
 		esac
 		;;
@@ -1769,10 +1870,10 @@ __git_complete_force_with_lease ()
 	--*=)
 		;;
 	*:*)
-		__gitcomp_nl "$(__git_refs)" "" "${cur_#*:}"
+		__git_complete_refs --cur="${cur_#*:}"
 		;;
 	*)
-		__gitcomp_nl "$(__git_refs)" "" "$cur_"
+		__git_complete_refs --cur="$cur_"
 		;;
 	esac
 }
@@ -1848,7 +1949,7 @@ _git_rebase ()
 
 		return
 	esac
-	__gitcomp_nl "$(__git_refs)"
+	__git_complete_refs
 }
 
 _git_reflog ()
@@ -1859,7 +1960,7 @@ _git_reflog ()
 	if [ -z "$subcommand" ]; then
 		__gitcomp "$subcommands"
 	else
-		__gitcomp_nl "$(__git_refs)"
+		__git_complete_refs
 	fi
 }
 
@@ -2005,7 +2106,7 @@ _git_config ()
 		return
 		;;
 	branch.*.merge)
-		__gitcomp_nl "$(__git_refs)"
+		__git_complete_refs
 		return
 		;;
 	branch.*.rebase)
@@ -2109,7 +2210,7 @@ _git_config ()
 		;;
 	branch.*)
 		local pfx="${cur%.*}." cur_="${cur#*.}"
-		__gitcomp_nl "$(__git_heads)" "$pfx" "$cur_" "."
+		__gitcomp_direct "$(__git_heads "$pfx" "$cur_" ".")"
 		__gitcomp_nl_append $'autosetupmerge\nautosetuprebase\n' "$pfx" "$cur_"
 		return
 		;;
@@ -2516,7 +2617,7 @@ _git_replace ()
 		return
 		;;
 	esac
-	__gitcomp_nl "$(__git_refs)"
+	__git_complete_refs
 }
 
 _git_rerere ()
@@ -2540,7 +2641,7 @@ _git_reset ()
 		return
 		;;
 	esac
-	__gitcomp_nl "$(__git_refs)"
+	__git_complete_refs
 }
 
 _git_revert ()
@@ -2559,7 +2660,7 @@ _git_revert ()
 		return
 		;;
 	esac
-	__gitcomp_nl "$(__git_refs)"
+	__git_complete_refs
 }
 
 _git_rm ()
@@ -2667,7 +2768,7 @@ _git_stash ()
 			;;
 		branch,*)
 			if [ $cword -eq 3 ]; then
-				__gitcomp_nl "$(__git_refs)";
+				__git_complete_refs
 			else
 				__gitcomp_nl "$(__git stash list \
 						| sed -n -e 's/:.*//p')"
@@ -2834,7 +2935,7 @@ _git_tag ()
 		i="${words[c]}"
 		case "$i" in
 		-d|-v)
-			__gitcomp_nl "$(__git_tags)"
+			__gitcomp_direct "$(__git_tags "" "$cur" " ")"
 			return
 			;;
 		-f)
@@ -2849,11 +2950,11 @@ _git_tag ()
 		;;
 	-*|tag)
 		if [ $f = 1 ]; then
-			__gitcomp_nl "$(__git_tags)"
+			__gitcomp_direct "$(__git_tags "" "$cur" " ")"
 		fi
 		;;
 	*)
-		__gitcomp_nl "$(__git_refs)"
+		__git_complete_refs
 		;;
 	esac
 
@@ -3024,6 +3125,15 @@ if [[ -n ${ZSH_VERSION-} ]]; then
 		esac
 	}
 
+	__gitcomp_direct ()
+	{
+		emulate -L zsh
+
+		local IFS=$'\n'
+		compset -P '*[=:]'
+		compadd -Q -- ${=1} && _ret=0
+	}
+
 	__gitcomp_nl ()
 	{
 		emulate -L zsh
diff --git a/contrib/completion/git-completion.zsh b/contrib/completion/git-completion.zsh
index e25541308a..c3521fbfc4 100644
--- a/contrib/completion/git-completion.zsh
+++ b/contrib/completion/git-completion.zsh
@@ -67,6 +67,15 @@ __gitcomp ()
 	esac
 }
 
+__gitcomp_direct ()
+{
+	emulate -L zsh
+
+	local IFS=$'\n'
+	compset -P '*[=:]'
+	compadd -Q -- ${=1} && _ret=0
+}
+
 __gitcomp_nl ()
 {
 	emulate -L zsh