completion: introduce __gitcomp_nl_append ()

There are situations where multiple classes of completions possible. For
example

  branch.<TAB>

should try to complete

  branch.master.
  branch.autosetupmerge
  branch.autosetuprebase

The first candidate has the suffix ".", and the second/ third candidates
have the suffix " ". To facilitate completions of this kind, create a
variation of __gitcomp_nl () that appends to the existing list of
completion candidates, COMPREPLY.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -178,16 +178,22 @@ _get_comp_words_by_ref ()
 }
 fi
 
-__gitcompadd ()
+__gitcompappend ()
 {
-	local i=0
+	local i=${#COMPREPLY[@]}
 	for x in $1; do
 		if [[ "$x" == "$3"* ]]; then
 			COMPREPLY[i++]="$2$x$4"
 		fi
 	done
 }
 
+__gitcompadd ()
+{
+	COMPREPLY=()
+	__gitcompappend "$@"
+}
+
 # Generates completion reply, appending a space to possible completion words,
 # if necessary.
 # It accepts 1 to 4 arguments:
@@ -218,6 +224,14 @@ __gitcomp ()
 	esac
 }
 
+# Variation of __gitcomp_nl () that appends to the existing list of
+# completion candidates, COMPREPLY.
+__gitcomp_nl_append ()
+{
+	local IFS=$'\n'
+	__gitcompappend "$1" "${2-}" "${3-$cur}" "${4- }"
+}
+
 # Generates completion reply from newline-separated possible completion words
 # by appending a space to all of them.
 # It accepts 1 to 4 arguments:
@@ -229,8 +243,8 @@ __gitcomp ()
 #    appended.
 __gitcomp_nl ()
 {
-	local IFS=$'\n'
-	__gitcompadd "$1" "${2-}" "${3-$cur}" "${4- }"
+	COMPREPLY=()
+	__gitcomp_nl_append "$@"
 }
 
 # Generates completion reply with compgen from newline-separated possible

contrib/completion/git-completion.zsh

@@ -76,6 +76,14 @@ __gitcomp_nl ()
 	compadd -Q -S "${4- }" -p "${2-}" -- ${=1} && _ret=0
 }
 
+__gitcomp_nl_append ()
+{
+	emulate -L zsh
+
+	local IFS=$'\n'
+	compadd -Q -S "${4- }" -p "${2-}" -- ${=1} && _ret=0
+}
+
 __gitcomp_file ()
 {
 	emulate -L zsh