If the -L option is used to specify a line range in git log, and the end
of the range is past the end of the file, git will fail with a fatal
error. This commit prevents such behaviour - instead we perform the log
for existing lines within the specified range.

This commit also fixes a corner case where -L ,-n:file would be treated
as a log over the whole file. Now we treat this as -L 1,-n:file and
blame the first line of the file instead.

Signed-off-by: Isabella Stephens <redacted>
---

diff --git a/t/t4211-line-log.sh b/t/t4211-line-log.sh

@@ -86,12 +85,7 @@ test_expect_success '-L ,Y (Y == nlines)' '
 test_expect_success '-L ,Y (Y == nlines + 1)' '
        n=$(expr $(wc -l <b.c) + 1) &&
-       test_must_fail git log -L ,$n:b.c
-'
-
-test_expect_success '-L ,Y (Y == nlines + 2)' '
-       n=$(expr $(wc -l <b.c) + 2) &&
-       test_must_fail git log -L ,$n:b.c
+       git log -L ,$n:b.c
 '