git-extra: wrap 'notepad' so it can serve as Git's editor

Windows' notepad.exe handles only DOS line endings and it cannot wrap
any lines. That makes it less useful as a commit message editor.

So let's wrap it in a shell script that adds DOS line endings before,
and strips them after running notepad.exe.

Also, to make it appropriate as commit message editor, interpret a
new config variable "format.commitMessageColumns" and line-wrap the
commit message accordingly.

This very commit message, in fact, was written using that notepad
wrapper with "format.commitMessageColumns" set to 72.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

git-extra/PKGBUILD

@@ -41,6 +41,7 @@ package() {
   install -m644 $startdir/inputrc $pkgdir/etc
   install -m644 $startdir/vimrc $pkgdir/etc
   install -m755 $startdir/vi $pkgdir/usr/bin
+  install -m755 $startdir/notepad $pkgdir/usr/bin
   install -m755 $startdir/wordpad $pkgdir/usr/bin
   install -m755 create-shortcut.exe $pkgdir/$mingwdir/bin
   install -m755 $startdir/git-prompt.sh $pkgdir/etc/profile.d

git-extra/notepad

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+die () {
+	echo "$*" >&2
+	exit 1
+}
+
+test $# = 1 ||
+die "Usage: $0 <file>"
+
+if test -f "$1"
+then
+	unix2dos.exe "$1"
+fi &&
+notepad.exe "$1" &&
+dos2unix.exe "$1" &&
+case "$1" in
+*/COMMIT_EDITMSG|*\\COMMIT_EDITMSG)
+	columns="$(git config format.commitmessagecolumns)" &&
+	test -z "$columns" || {
+		msg="$(fmt.exe -s -w "$columns" "$1")" &&
+		printf "%s" "$msg" >"$1"
+	}
+	;;
+esac