log: fix -L bounds checking bug

When 12da1d1 added -L support to git-log, a broken bounds check was
copied from git-blame -L which incorrectly allows -LX to extend one line
past end of file without reporting an error.  Instead, it generates an
empty range.  Fix this bug.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

line-log.c

@@ -594,13 +594,13 @@ parse_lines(struct commit *commit, const char *prefix, struct string_list *args)
 				    lines, &begin, &end,
 				    full_name))
 			die("malformed -L argument '%s'", range_part);
+		if (lines < end || ((lines || begin) && lines < begin))
+			die("file %s has only %lu lines", name_part, lines);
 		if (begin < 1)
 			begin = 1;
 		if (end < 1)
 			end = lines;
 		begin--;
-		if (lines < end || lines < begin)
-			die("file %s has only %ld lines", name_part, lines);
 		line_log_data_insert(&ranges, full_name, begin, end);
 
 		free_filespec(spec);

t/t4211-line-log.sh

@@ -69,7 +69,7 @@ test_expect_success '-L X (X == nlines)' '
 	git log -L $n:b.c
 '
 
-test_expect_failure '-L X (X == nlines + 1)' '
+test_expect_success '-L X (X == nlines + 1)' '
 	n=$(expr $(wc -l <b.c) + 1) &&
 	test_must_fail git log -L $n:b.c
 '