format-patch: append --signature after notes

When appending a new signature with "format-patch --signature", if
the "--notes" option is also in effect, the location of the new
signature (and if the signature should be added in the first place)
should be decided using the contents of the original commit log
message, before the message from the notes is added.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

log-tree.c

@@ -672,12 +672,14 @@ void show_log(struct rev_info *opt)
 	ctx.reflog_info = opt->reflog_info;
 	ctx.fmt = opt->commit_format;
 	pretty_print_commit(&ctx, commit, &msgbuf);
+
+	if (opt->add_signoff)
+		append_signoff(&msgbuf, opt->add_signoff);
+
 	if ((ctx.fmt != CMIT_FMT_USERFORMAT) &&
 	    ctx.notes_message && *ctx.notes_message)
 		strbuf_addstr(&msgbuf, ctx.notes_message);
 
-	if (opt->add_signoff)
-		append_signoff(&msgbuf, opt->add_signoff);
 	if (opt->show_log_size) {
 		printf("log size %i\n", (int)msgbuf.len);
 		graph_show_oneline(opt->graph);

t/t4014-format-patch.sh

@@ -616,8 +616,16 @@ test_expect_success 'format-patch --in-reply-to' '
 '
 
 test_expect_success 'format-patch --signoff' '
-	git format-patch -1 --signoff --stdout |
-	grep "^Signed-off-by: $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>"
+	git format-patch -1 --signoff --stdout >out &&
+	grep "^Signed-off-by: $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>" out
+'
+
+test_expect_success 'format-patch --notes --signoff' '
+	git notes --ref test add -m "test message" HEAD &&
+	git format-patch -1 --signoff --stdout --notes=test >out &&
+	# Notes message must come after S-o-b
+	! sed "/^Signed-off-by: /q" out | grep "test message" &&
+	sed "1,/^Signed-off-by: /d" out | grep "test message"
 '
 
 echo "fatal: --name-only does not make sense" > expect.name-only