[TopGit RFC PATCH] tg mail: new command for mailing patches

@@ -5,6 +5,8 @@ tg-delete
 tg-delete.txt
 tg-info
 tg-info.txt
+tg-mail
+tg-mail.txt
 tg-patch
 tg-patch.txt
 tg-summary

@@ -272,6 +272,24 @@ tg patch
 	TODO: tg patch -i to base at index instead of branch,
 		-w for working tree
 
+tg mail
+~~~~~~~
+	Send a patch from the current or specified topic branch as
+	email.
+
+	Takes the patch given on the command line and emails it out.
+	Destination addresses such as To, Cc and Bcc are taken from the
+	patch header.
+
+	Since it actually boils down to `git send-email` please refer to
+	it's documentation for details on how to setup email for git.
+
+
+	TODO: tg mail patchfile  to mail an already exported patch
+	TODO: mailing patch series
+	TODO: specifying additional options and addresses on command
+	      line
+
 tg remote
 ~~~~~~~~~
 	Register given remote as TopGit-controlled. This will create

@@ -0,0 +1,53 @@
+#!/bin/sh
+# TopGit - A different patch queue manager
+# GPLv2
+
+name=
+
+
+## Parse options
+
+while [ -n "$1" ]; do
+	arg="$1"; shift
+	case "$arg" in
+	-*)
+		echo "Usage: tg [...] mail [NAME]" >&2
+		exit 1;;
+	*)
+		[ -z "$name" ] || die "name already specified ($name)"
+		name="$arg";;
+	esac
+done
+
+# TODO refactor me into something common?
+[ -n "$name" ] || name="$(git symbolic-ref HEAD | sed 's#^refs/heads/##')"
+base_rev="$(git rev-parse --short --verify "refs/top-bases/$name" 2>/dev/null)" ||
+	die "not a TopGit-controlled branch"
+
+
+patchfile="$(mktemp -t tg-mail.XXXXXX)"
+
+$tg patch $name >"$patchfile"
+
+hlines=$(grep -n -m 1 '^---' "$patchfile" | sed 's/:---//')
+header=$(head -$(($hlines - 1)) "$patchfile")
+
+
+
+from="$(echo "$header" | grep '^From:' | sed 's/From:\s*//')"
+to="$(echo "$header" | grep '^To:' | sed 's/To:\s*//')"
+
+
+# XXX I can't get quoting right without arrays
+[ -n "$from" ] && from=(--from "$from")
+[ -n "$to"   ] && to=(--to "$to") # FIXME there could be multimple To
+
+people=()
+[ -n "$from" ] && people=("${people[@]}" "${from[@]}")
+[ -n "$to" ]   && people=("${people[@]}" "${to[@]}")
+
+
+# NOTE git-send-email handles cc itself
+git send-email "${people[@]}" "$patchfile"
+
+rm "$patchfile"