reset: improve worktree safety valves

The existing code checked to make sure we were not in a bare
repository when doing a hard reset. However, we should take
this one step further, and make sure we are in a worktree.
Otherwise, we can end up munging files inside of '.git'.

Furthermore, we should do the same check for --merge resets,
which have the same properties. Actually, a merge reset of
HEAD^ would already complain, since further down in the code
we want a worktree. However, it is nicer to check up-front;
then we are sure we cover all cases ("git reset --merge"
would run, even though it wasn't doing anything) and we can
give a more specific message.

Add tests to t7103 to cover these cases and some missing ones.

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

diff --git a/builtin-reset.c b/builtin-reset.c
index 73e6022..11d1c6e 100644 (file)
--- a/builtin-reset.c
+++ b/builtin-reset.c
@@ -286,8 +286,10 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
        if (reset_type == NONE)
                reset_type = MIXED; /* by default */
 
-       if (reset_type == HARD && is_bare_repository())
-               die("hard reset makes no sense in a bare repository");
+       if ((reset_type == HARD || reset_type == MERGE)
+           && !is_inside_work_tree())
+               die("%s reset requires a work tree",
+                   reset_type_names[reset_type]);
 
        /* Soft reset does not touch the index file nor the working tree
         * at all, but requires them in a good order.  Other resets reset

diff --git a/t/t7103-reset-bare.sh b/t/t7103-reset-bare.sh
index 42bf518..68041df 100755 (executable)
--- a/t/t7103-reset-bare.sh
+++ b/t/t7103-reset-bare.sh
@@ -11,16 +11,42 @@ test_expect_success 'setup non-bare' '
        git commit -a -m two
 '
 
+test_expect_success 'hard reset requires a worktree' '
+       (cd .git &&
+        test_must_fail git reset --hard)
+'
+
+test_expect_success 'merge reset requires a worktree' '
+       (cd .git &&
+        test_must_fail git reset --merge)
+'
+
+test_expect_success 'mixed reset is ok' '
+       (cd .git && git reset)
+'
+
+test_expect_success 'soft reset is ok' '
+       (cd .git && git reset --soft)
+'
+
 test_expect_success 'setup bare' '
        git clone --bare . bare.git &&
        cd bare.git
 '
 
-test_expect_success 'hard reset is not allowed' '
-       test_must_fail  git reset --hard HEAD^
+test_expect_success 'hard reset is not allowed in bare' '
+       test_must_fail git reset --hard HEAD^
+'
+
+test_expect_success 'merge reset is not allowed in bare' '
+       test_must_fail git reset --merge HEAD^
+'
+
+test_expect_success 'mixed reset is not allowed in bare' '
+       test_must_fail git reset --mixed HEAD^
 '
 
-test_expect_success 'soft reset is allowed' '
+test_expect_success 'soft reset is allowed in bare' '
        git reset --soft HEAD^ &&
        test "`git show --pretty=format:%s | head -n 1`" = "one"
 '