read-tree: explicitly disallow prefixes with a leading '/'

Exit with an error if a prefix provided to `git read-tree --prefix` begins
with '/'. In most cases, prefixes like this result in an "invalid path"
error; however, the repository root would be interpreted as valid when
specified as '--prefix=/'. This is due to leniency around trailing directory
separators on prefixes (e.g., allowing both '--prefix=my-dir' and
'--prefix=my-dir/') - the '/' in the prefix is actually the *trailing*
slash, although it could be misinterpreted as a *leading* slash.

To remove the confusing repo root-as-'/' case and make it clear that
prefixes should not begin with '/', exit with an error if the first
character of the provided prefix is '/'.

Helped-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Victoria Dye 2022-03-01 20:24:26 +00:00 committed by Junio C Hamano
parent 2c521b0e49
commit cc89331ddc
2 changed files with 14 additions and 0 deletions

View File

@ -166,6 +166,10 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
if (1 < opts.merge + opts.reset + prefix_set)
die("Which one? -m, --reset, or --prefix?");
/* Prefix should not start with a directory separator */
if (opts.prefix && opts.prefix[0] == '/')
die("Invalid prefix, prefix cannot start with '/'");
if (opts.reset)
opts.reset = UNPACK_RESET_OVERWRITE_UNTRACKED;

View File

@ -25,4 +25,14 @@ test_expect_success 'read-tree --prefix' '
cmp expect actual
'
test_expect_success 'read-tree --prefix with leading slash exits with error' '
git rm -rf . &&
test_must_fail git read-tree --prefix=/two/ $tree &&
git read-tree --prefix=two/ $tree &&
git rm -rf . &&
test_must_fail git read-tree --prefix=/ $tree &&
git read-tree --prefix= $tree
'
test_done