submodule update: add convenience option --init

When a submodule is not initialized and you do not want to change the
defaults from .gitmodules anyway, you can now say

	$ git submodule update --init <name>

When "update" is called without --init on an uninitialized submodule,
a hint to use --init is printed.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-submodule.txt

@@ -11,7 +11,8 @@ SYNOPSIS
 [verse]
 'git-submodule' [--quiet] add [-b branch] [--] <repository> [<path>]
 'git-submodule' [--quiet] status [--cached] [--] [<path>...]
-'git-submodule' [--quiet] [init|update] [--] [<path>...]
+'git-submodule' [--quiet] init [--] [<path>...]
+'git-submodule' [--quiet] update [--init] [--] [<path>...]
 'git-submodule' [--quiet] summary [--summary-limit <n>] [commit] [--] [<path>...]
 
 
@@ -47,6 +48,10 @@ update::
 	Update the registered submodules, i.e. clone missing submodules and
 	checkout the commit specified in the index of the containing repository.
 	This will make the submodules HEAD be detached.
++
+If the submodule is not yet initialized, and you just want to use the
+setting as stored in .gitmodules, you can automatically initialize the
+submodule with the --init option.
 
 summary::
 	Show commit summary between the given commit (defaults to HEAD) and

git-submodule.sh

@@ -5,7 +5,7 @@
 # Copyright (c) 2007 Lars Hjemli
 
 USAGE="[--quiet] [--cached] \
-[add <repo> [-b branch]|status|init|update|summary [-n|--summary-limit <n>] [<commit>]] \
+[add <repo> [-b branch]|status|init|update [-i|--init]|summary [-n|--summary-limit <n>] [<commit>]] \
 [--] [<path>...]"
 OPTIONS_SPEC=
 . git-sh-setup
@@ -271,6 +271,10 @@ cmd_update()
 		-q|--quiet)
 			quiet=1
 			;;
+		-i|--init)
+			shift
+			cmd_init "$@" || return
+			;;
 		--)
 			shift
 			break
@@ -296,6 +300,7 @@ cmd_update()
 			# path have been specified
 			test "$#" != "0" &&
 			say "Submodule path '$path' not initialized"
+			say "Maybe you want to use 'update --init'?"
 			continue
 		fi
 

t/t7400-submodule-basic.sh

@@ -196,4 +196,17 @@ test_expect_success 'apply submodule diff' '
 	test -z "$D"
 '
 
+test_expect_success 'update --init' '
+
+	mv init init2 &&
+	git config -f .gitmodules submodule.example.url "$(pwd)/init2" &&
+	git config --remove-section submodule.example
+	git submodule update init > update.out &&
+	grep "not initialized" update.out &&
+	test ! -d init/.git &&
+	git submodule update --init init &&
+	test -d init/.git
+
+'
+
 test_done