mailinfo: better parse email adresses containg parentheses

When using git-rebase, author fields containing a ')' at the last position
had the close-parens character removed; the removal should be done only
when it is of this form:

        user@host (User Name)

i.e. the remainder after stripping the e-mail address part is enclosed in
a parentheses pair as a whole, not for addresses like this:

        User Name (me) <user@host>

Signed-off-by: Philippe Bruhat (BooK) <book@cpan.org>
Acked-by: Lukas Sandström <lukass@etek.chalmers.se>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-mailinfo.c

@@ -115,10 +115,10 @@ static void handle_from(const struct strbuf *from)
 	 * the () pair at the end.
 	 */
 	strbuf_trim(&f);
-	if (f.buf[0] == '(')
-		strbuf_remove(&name, 0, 1);
-	if (f.len && f.buf[f.len - 1] == ')')
+	if (f.buf[0] == '(' && f.len && f.buf[f.len - 1] == ')') {
+		strbuf_remove(&f, 0, 1);
 		strbuf_setlen(&f, f.len - 1);
+	}
 
 	get_sane_name(&name, &f, &email);
 	strbuf_release(&f);