[PATCH v3 3/4] git-submodule: New subcommand 'summary' (3) - limit summary size

[Ping Yin <pkufranky@gmail.com>]

This patch teaches git-submodule an option '--summary-limit|-n <number>'
to limit number of commits in total for the summary. Number 0 will disable
summary and minus number means unlimted (the default).

For beauty and clarification, the fork-point (i.e. the last commits for
both backward and forward sections) will always be shown disregarding the
given limit. So actual summary size may be greater than the given limit.

'git submodule summary -n 2 sm1' and 'git submodule summary -n 3 sm1'
will show the same in the super project mentioned in last patch.

---------------------------------------
 $ git submodule summary -n 2 sm1
 # Submodules modifiled: sm1
 #
 # * sm1 354cd45...3f751e5:
 #   <one line message for C
 #   <one line message for B
 #   >...
 #   >one line message for E
 #
---------------------------------------

Signed-off-by: Ping Yin <pkufranky@gmail.com>
---
 git-submodule.sh |   65 +++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index 3313d6c..dfd2952 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -4,7 +4,9 @@
 #
 # Copyright (c) 2007 Lars Hjemli
 
-USAGE='[--quiet] [--cached] [add <repo> [-b branch]|status|init|update|summary [<commit>]] [--] [<path>...]'
+USAGE="[--quiet] [--cached] \
+[add <repo> [-b branch]|status|init|update|summary [-n|--summary-limit <n>] [<commit>]] \
+[--] [<path>...]"
 OPTIONS_SPEC=
 . git-sh-setup
 require_work_tree
@@ -329,6 +331,8 @@ set_name_rev () {
 # $@ = [commit (default 'HEAD'),] requested paths (default all)
 #
 cmd_summary() {
+	summary_limit=-1
+
 	# parse $args after "submodule ... summary".
 	while test $# -ne 0
 	do
@@ -336,6 +340,15 @@ cmd_summary() {
 		--cached)
 			cached="$1"
 			;;
+		-n|--summary-limit)
+			if summary_limit=$(($2 + 0)) 2>/dev/null && test "$summary_limit" = "$2"
+			then
+				:
+			else
+				usage
+			fi
+			shift
+			;;
 		--)
 			shift
 			break
@@ -350,6 +363,8 @@ cmd_summary() {
 		shift
 	done
 
+	test $summary_limit = 0 && return
+
 	if rev=$(git rev-parse --verify "$1^0" 2>/dev/null)
 	then
 		head=$rev
@@ -442,8 +457,52 @@ cmd_summary() {
 			# Don't give error msg for modification whose dst is not submodule, i.e. deleted or changed to blob
 			test $mod_dst = 160000 && echo "$errmsg"
 		else
-			test -n "$left" && echo "$left"
-			test -n "$right" && echo "$right"
+			lc0=0
+			rc0=0
+			test -n "$left" && lc0=$(echo "$left" | wc -l)
+			test -n "$right" && rc0=$(echo "$right" | wc -l)
+
+			if test $summary_limit -lt 0
+			then
+				lc=$lc0
+				rc=$rc0
+			elif test $lc0 -lt $summary_limit
+			then
+				lc=$lc0
+				rc=$(($summary_limit-$lc))
+			else
+				lc=$summary_limit
+				rc=1
+			fi
+
+			if test $rc -gt $rc0
+			then
+				rc=$rc0
+			fi
+
+			if test -n "$left"
+			then
+				skip=$(($lc0-$lc))
+				echo "$left" | head -$(($lc-1))
+				case $skip in
+					0) : ;;
+					1) echo "  <..." ;;
+					*) echo "  <... ($skip more)" ;;
+				esac
+				echo "$left" | tail -1
+			fi
+
+			if test -n "$right"
+			then
+				skip=$(($rc0-$rc))
+				echo "$right" | head -$(($rc-1))
+				case $skip in
+					0) : ;;
+					1) echo "  <..." ;;
+					*) echo "  <... ($skip more)" ;;
+				esac
+				echo "$right" | tail -1
+			fi
 		fi
 		echo
 	done | sed -e 's/^/# /'
-- 
1.5.4.3.347.g5314c