fsck: warn about ".git" in trees

Having a ".git" entry inside a tree can cause confusing
results on checkout. At the top-level, you could not
checkout such a tree, as it would complain about overwriting
the real ".git" directory. In a subdirectory, you might
check it out, but performing operations in the subdirectory
would confusingly consider the in-tree ".git" directory as
the repository.

The regular git tools already make it hard to accidentally
add such an entry to a tree, and do not allow such entries
to enter the index at all. Teaching fsck about it provides
an additional safety check, and let's us avoid propagating
any such bogosity when transfer.fsckObjects is on.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/fsck.c b/fsck.c
index 31c9a513951418991753bdaf8495d7c9ca7d0603..99c049767484288f273f036b57683df04c1ef0df 100644 (file)
--- a/fsck.c
+++ b/fsck.c
@@ -144,6 +144,7 @@ static int fsck_tree(struct tree *item, int strict, fsck_error error_func)
        int has_empty_name = 0;
        int has_dot = 0;
        int has_dotdot = 0;
+       int has_dotgit = 0;
        int has_zero_pad = 0;
        int has_bad_modes = 0;
        int has_dup_entries = 0;
@@ -174,6 +175,8 @@ static int fsck_tree(struct tree *item, int strict, fsck_error error_func)
                        has_dot = 1;
                if (!strcmp(name, ".."))
                        has_dotdot = 1;
+               if (!strcmp(name, ".git"))
+                       has_dotgit = 1;
                has_zero_pad |= *(char *)desc.buffer == '0';
                update_tree_entry(&desc);
 
@@ -227,6 +230,8 @@ static int fsck_tree(struct tree *item, int strict, fsck_error error_func)
                retval += error_func(&item->object, FSCK_WARN, "contains '.'");
        if (has_dotdot)
                retval += error_func(&item->object, FSCK_WARN, "contains '..'");
+       if (has_dotgit)
+               retval += error_func(&item->object, FSCK_WARN, "contains '.git'");
        if (has_zero_pad)
                retval += error_func(&item->object, FSCK_WARN, "contains zero-padded file modes");
        if (has_bad_modes)

diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index 0b5c30b4d95cf2f94f706188fb1841ad8c8e3459..d730734fde8e4de69fdf2662915bc67342198fc8 100755 (executable)
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -253,4 +253,19 @@ test_expect_success 'fsck notices "." and ".." in trees' '
        )
 '
 
+test_expect_success 'fsck notices ".git" in trees' '
+       (
+               git init dotgit &&
+               cd dotgit &&
+               blob=$(echo foo | git hash-object -w --stdin) &&
+               tab=$(printf "\\t") &&
+               git mktree <<-EOF &&
+               100644 blob $blob$tab.git
+               EOF
+               git fsck 2>out &&
+               cat out &&
+               grep "warning.*\\.git" out
+       )
+'
+
 test_done