checkout: implement "-" abbreviation, add docs and tests

diff --git a/t/t4030-diff-textconv.sh b/t/t4030-diff-textconv.sh
index 0b76e7c97a511e5d5bbedaf54d4bab10a15caeb2..2f27a0ba9ec002b1a6e4d3bd0ed1dc7484d4d14e 100755 (executable)
--- a/t/t4030-diff-textconv.sh
+++ b/t/t4030-diff-textconv.sh
@@ -29,7 +29,7 @@ test_expect_success 'setup binary file with history' '
        printf "\\0\\n" >file &&
        git add file &&
        git commit -m one &&
-       printf "\\1\\n" >>file &&
+       printf "\\01\\n" >>file &&
        git add file &&
        git commit -m two
 '