Merge branch 'py/submodule'

* py/submodule:
  git-submodule summary: fix that some "wc" flavors produce leading spaces
  git-submodule summary: test
  git-submodule summary: documentation
  git-submodule summary: limit summary size
  git-submodule summary: show commit summary
  git-submodule summary: code framework

3 files changed, 386 insertions, 8 deletions

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index b4d01605a5..41f9f63566 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -12,6 +12,7 @@ SYNOPSIS
 'git-submodule' [--quiet] add [-b branch] [--] <repository> [<path>]
 'git-submodule' [--quiet] status [--cached] [--] [<path>...]
 'git-submodule' [--quiet] [init|update] [--] [<path>...]
+'git-submodule' [--quiet] summary [--summary-limit <n>] [commit] [--] [<path>...]
 
 
 COMMANDS
@@ -47,6 +48,11 @@ update::
 	checkout the commit specified in the index of the containing repository.
 	This will make the submodules HEAD be detached.
 
+summary::
+	Show commit summary between the given commit (defaults to HEAD) and
+	working tree/index. For a submodule in question, a series of commits
+	in the submodule between the given super project commit and the
+	index or working tree (switched by --cached) are shown.
 
 OPTIONS
 -------
@@ -57,9 +63,16 @@ OPTIONS
 	Branch of repository to add as submodule.
 
 --cached::
-	Display the SHA-1 stored in the index, not the SHA-1 of the currently
-	checked out submodule commit. This option is only valid for the
-	status command.
+	This option is only valid for status and summary commands.  These
+	commands typically use the commit found in the submodule HEAD, but
+	with this option, the commit stored in the index is used instead.
+
+-n, --summary-limit::
+	This option is only valid for the summary command.
+	Limit the summary size (number of commits shown in total).
+	Giving 0 will disable the summary; a negative number means unlimted
+	(the default). This limit only applies to modified submodules. The
+	size is always limited to 1 for added/deleted/typechanged submodules.
 
 <path>::
 	Path to submodule(s). When specified this will restrict the command
diff --git a/git-submodule.sh b/git-submodule.sh
index 7171cb60ab..5f1d5ef06e 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] [--] [<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
@@ -330,7 +332,175 @@ set_name_rev () {
 	) )
 	test -z "$revname" || revname=" ($revname)"
 }
+#
+# Show commit summary for submodules in index or working tree
+#
+# If '--cached' is given, show summary between index and given commit,
+# or between working tree and given commit
+#
+# $@ = [commit (default 'HEAD'),] requested paths (default all)
+#
+cmd_summary() {
+	summary_limit=-1
+
+	# parse $args after "submodule ... summary".
+	while test $# -ne 0
+	do
+		case "$1" in
+		--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
+			;;
+		-*)
+			usage
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done
+
+	test $summary_limit = 0 && return
+
+	if rev=$(git rev-parse --verify "$1^0" 2>/dev/null)
+	then
+		head=$rev
+		shift
+	else
+		head=HEAD
+	fi
+
+	cd_to_toplevel
+	# Get modified modules cared by user
+	modules=$(git diff-index $cached --raw $head -- "$@" |
+		grep -e '^:160000' -e '^:[0-7]* 160000' |
+		while read mod_src mod_dst sha1_src sha1_dst status name
+		do
+			# Always show modules deleted or type-changed (blob<->module)
+			test $status = D -o $status = T && echo "$name" && continue
+			# Also show added or modified modules which are checked out
+			GIT_DIR="$name/.git" git-rev-parse --git-dir >/dev/null 2>&1 &&
+			echo "$name"
+		done
+	)
+
+	test -n "$modules" &&
+	git diff-index $cached --raw $head -- $modules |
+	grep -e '^:160000' -e '^:[0-7]* 160000' |
+	cut -c2- |
+	while read mod_src mod_dst sha1_src sha1_dst status name
+	do
+		if test -z "$cached" &&
+			test $sha1_dst = 0000000000000000000000000000000000000000
+		then
+			case "$mod_dst" in
+			160000)
+				sha1_dst=$(GIT_DIR="$name/.git" git rev-parse HEAD)
+				;;
+			100644 | 100755 | 120000)
+				sha1_dst=$(git hash-object $name)
+				;;
+			000000)
+				;; # removed
+			*)
+				# unexpected type
+				echo >&2 "unexpected mode $mod_dst"
+				continue ;;
+			esac
+		fi
+		missing_src=
+		missing_dst=
+
+		test $mod_src = 160000 &&
+		! GIT_DIR="$name/.git" git-rev-parse --verify $sha1_src^0 >/dev/null 2>&1 &&
+		missing_src=t
+
+		test $mod_dst = 160000 &&
+		! GIT_DIR="$name/.git" git-rev-parse --verify $sha1_dst^0 >/dev/null 2>&1 &&
+		missing_dst=t
 
+		total_commits=
+		case "$missing_src,$missing_dst" in
+		t,)
+			errmsg="  Warn: $name doesn't contain commit $sha1_src"
+			;;
+		,t)
+			errmsg="  Warn: $name doesn't contain commit $sha1_dst"
+			;;
+		t,t)
+			errmsg="  Warn: $name doesn't contain commits $sha1_src and $sha1_dst"
+			;;
+		*)
+			errmsg=
+			total_commits=$(
+			if test $mod_src = 160000 -a $mod_dst = 160000
+			then
+				range="$sha1_src...$sha1_dst"
+			elif test $mod_src = 160000
+			then
+				range=$sha1_src
+			else
+				range=$sha1_dst
+			fi
+			GIT_DIR="$name/.git" \
+			git log --pretty=oneline --first-parent $range | wc -l
+			)
+			total_commits=" ($(($total_commits + 0)))"
+			;;
+		esac
+
+		sha1_abbr_src=$(echo $sha1_src | cut -c1-7)
+		sha1_abbr_dst=$(echo $sha1_dst | cut -c1-7)
+		if test $status = T
+		then
+			if test $mod_dst = 160000
+			then
+				echo "* $name $sha1_abbr_src(blob)->$sha1_abbr_dst(submodule)$total_commits:"
+			else
+				echo "* $name $sha1_abbr_src(submodule)->$sha1_abbr_dst(blob)$total_commits:"
+			fi
+		else
+			echo "* $name $sha1_abbr_src...$sha1_abbr_dst$total_commits:"
+		fi
+		if test -n "$errmsg"
+		then
+			# 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
+			if test $mod_src = 160000 -a $mod_dst = 160000
+			then
+				limit=
+				test $summary_limit -gt 0 && limit="-$summary_limit"
+				GIT_DIR="$name/.git" \
+				git log $limit --pretty='format:  %m %s' \
+				--first-parent $sha1_src...$sha1_dst
+			elif test $mod_dst = 160000
+			then
+				GIT_DIR="$name/.git" \
+				git log --pretty='format:  > %s' -1 $sha1_dst
+			else
+				GIT_DIR="$name/.git" \
+				git log --pretty='format:  < %s' -1 $sha1_src
+			fi
+			echo
+		fi
+		echo
+	done
+}
 #
 # List all submodules, prefixed with:
 #  - submodule not initialized
@@ -401,7 +571,7 @@ cmd_status()
 while test $# != 0 && test -z "$command"
 do
 	case "$1" in
-	add | init | update | status)
+	add | init | update | status | summary)
 		command=$1
 		;;
 	-q|--quiet)
@@ -416,7 +586,7 @@ do
 		branch="$2"; shift
 		;;
 	--cached)
-		cached=1
+		cached="$1"
 		;;
 	--)
 		break
@@ -440,8 +610,8 @@ then
 	usage
 fi
 
-# "--cached" is accepted only by "status"
-if test -n "$cached" && test "$command" != status
+# "--cached" is accepted only by "status" and "summary"
+if test -n "$cached" && test "$command" != status -a "$command" != summary
 then
 	usage
 fi
diff --git a/t/t7401-submodule-summary.sh b/t/t7401-submodule-summary.sh
new file mode 100755
index 0000000000..0f3c42ab35
--- /dev/null
+++ b/t/t7401-submodule-summary.sh
@@ -0,0 +1,195 @@
+#!/bin/sh
+#
+# Copyright (c) 2008 Ping Yin
+#
+
+test_description='Summary support for submodules
+
+This test tries to verify the sanity of summary subcommand of git-submodule.
+'
+
+. ./test-lib.sh
+
+add_file () {
+	sm=$1
+	shift
+	owd=$(pwd)
+	cd "$sm"
+	for name; do
+		echo "$name" > "$name" &&
+		git add "$name" &&
+		test_tick &&
+		git commit -m "Add $name"
+	done >/dev/null
+	git rev-parse --verify HEAD | cut -c1-7
+	cd "$owd"
+}
+commit_file () {
+	test_tick &&
+	git commit "$@" -m "Commit $*" >/dev/null
+}
+
+test_create_repo sm1 &&
+add_file . foo
+
+head1=$(add_file sm1 foo1 foo2)
+
+test_expect_success 'added submodule' "
+	git add sm1 &&
+	git submodule summary >actual &&
+	diff actual - <<-EOF
+* sm1 0000000...$head1 (2):
+  > Add foo2
+
+EOF
+"
+
+commit_file sm1 &&
+head2=$(add_file sm1 foo3)
+
+test_expect_success 'modified submodule(forward)' "
+	git submodule summary >actual &&
+	diff actual - <<-EOF
+* sm1 $head1...$head2 (1):
+  > Add foo3
+
+EOF
+"
+
+commit_file sm1 &&
+cd sm1 &&
+git reset --hard HEAD~2 >/dev/null &&
+head3=$(git rev-parse --verify HEAD | cut -c1-7) &&
+cd ..
+
+test_expect_success 'modified submodule(backward)' "
+    git submodule summary >actual &&
+    diff actual - <<-EOF
+* sm1 $head2...$head3 (2):
+  < Add foo3
+  < Add foo2
+
+EOF
+"
+
+head4=$(add_file sm1 foo4 foo5) &&
+head4_full=$(GIT_DIR=sm1/.git git rev-parse --verify HEAD)
+test_expect_success 'modified submodule(backward and forward)' "
+    git submodule summary >actual &&
+    diff actual - <<-EOF
+* sm1 $head2...$head4 (4):
+  > Add foo5
+  > Add foo4
+  < Add foo3
+  < Add foo2
+
+EOF
+"
+
+test_expect_success '--summary-limit' "
+    git submodule summary -n 3 >actual &&
+    diff actual - <<-EOF
+* sm1 $head2...$head4 (4):
+  > Add foo5
+  > Add foo4
+  < Add foo3
+
+EOF
+"
+
+commit_file sm1 &&
+mv sm1 sm1-bak &&
+echo sm1 >sm1 &&
+head5=$(git hash-object sm1 | cut -c1-7) &&
+git add sm1 &&
+rm -f sm1 &&
+mv sm1-bak sm1
+
+test_expect_success 'typechanged submodule(submodule->blob), --cached' "
+    git submodule summary --cached >actual &&
+    diff actual - <<-EOF
+* sm1 $head4(submodule)->$head5(blob) (3):
+  < Add foo5
+
+EOF
+"
+
+rm -rf sm1 &&
+git checkout-index sm1
+test_expect_success 'typechanged submodule(submodule->blob)' "
+    git submodule summary >actual &&
+    diff actual - <<-EOF
+* sm1 $head4(submodule)->$head5(blob):
+
+EOF
+"
+
+rm -f sm1 &&
+test_create_repo sm1 &&
+head6=$(add_file sm1 foo6 foo7)
+test_expect_success 'nonexistent commit' "
+    git submodule summary >actual &&
+    diff actual - <<-EOF
+* sm1 $head4...$head6:
+  Warn: sm1 doesn't contain commit $head4_full
+
+EOF
+"
+
+commit_file
+test_expect_success 'typechanged submodule(blob->submodule)' "
+    git submodule summary >actual &&
+    diff actual - <<-EOF
+* sm1 $head5(blob)->$head6(submodule) (2):
+  > Add foo7
+
+EOF
+"
+
+commit_file sm1 &&
+rm -rf sm1
+test_expect_success 'deleted submodule' "
+    git submodule summary >actual &&
+    diff actual - <<-EOF
+* sm1 $head6...0000000:
+
+EOF
+"
+
+test_create_repo sm2 &&
+head7=$(add_file sm2 foo8 foo9) &&
+git add sm2
+
+test_expect_success 'multiple submodules' "
+    git submodule summary >actual &&
+    diff actual - <<-EOF
+* sm1 $head6...0000000:
+
+* sm2 0000000...$head7 (2):
+  > Add foo9
+
+EOF
+"
+
+test_expect_success 'path filter' "
+    git submodule summary sm2 >actual &&
+    diff actual - <<-EOF
+* sm2 0000000...$head7 (2):
+  > Add foo9
+
+EOF
+"
+
+commit_file sm2
+test_expect_success 'given commit' "
+    git submodule summary HEAD^ >actual &&
+    diff actual - <<-EOF
+* sm1 $head6...0000000:
+
+* sm2 0000000...$head7 (2):
+  > Add foo9
+
+EOF
+"
+
+test_done