sparse-checkout: stop blocking empty workdirs

Remove the error condition when updating the sparse-checkout leaves
an empty working directory.

This behavior was added in 9e1afb167 (sparse checkout: inhibit empty
worktree, 2009-08-20). The comment was added in a7bc906f2 (Add
explanation why we do not allow to sparse checkout to empty working
tree, 2011-09-22) in response to a "dubious" comment in 84563a624
(unpack-trees.c: cosmetic fix, 2010-12-22).

With the recent "cone mode" and "git sparse-checkout init [--cone]"
command, it is common to set a reasonable sparse-checkout pattern
set of

	/*
	!/*/

which matches only files at root. If the repository has no such files,
then their "git sparse-checkout init" command will fail.

Now that we expect this to be a common pattern, we should not have the
commands fail on an empty working directory. If it is a confusing
result, then the user can recover with "git sparse-checkout disable"
or "git sparse-checkout set". This is especially simple when using cone
mode.

Reported-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t1011-read-tree-sparse-checkout.sh b/t/t1011-read-tree-sparse-checkout.sh
index 63223e13bd1bd20d2539a3e577a84c47416b5ed5..140f45997736c0ead2d059183881a5cbf2c96758 100755 (executable)
--- a/t/t1011-read-tree-sparse-checkout.sh
+++ b/t/t1011-read-tree-sparse-checkout.sh
@@ -74,13 +74,19 @@ test_expect_success 'read-tree --no-sparse-checkout with empty .git/info/sparse-
 test_expect_success 'read-tree with empty .git/info/sparse-checkout' '
        git config core.sparsecheckout true &&
        echo >.git/info/sparse-checkout &&
-       read_tree_u_must_fail -m -u HEAD &&
+       read_tree_u_must_succeed -m -u HEAD &&
        git ls-files --stage >result &&
        test_cmp expected result &&
        git ls-files -t >result &&
+       cat >expected.swt <<-\EOF &&
+       S init.t
+       S sub/added
+       S sub/addedtoo
+       S subsub/added
+       EOF
        test_cmp expected.swt result &&
-       test -f init.t &&
-       test -f sub/added
+       ! test -f init.t &&
+       ! test -f sub/added
 '
 
 test_expect_success 'match directories with trailing slash' '

diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index dee99eeec305ea77b9d6ad9cdd904409e157da85..88cdde255cdad7a0b138033b3ff9a997e4a2c0b2 100755 (executable)
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh
@@ -106,10 +106,8 @@ test_expect_success 'set enables config' '
                cd empty-config &&
                test_commit test file &&
                test_path_is_missing .git/config.worktree &&
-               test_must_fail git sparse-checkout set nothing &&
+               git sparse-checkout set nothing &&
                test_path_is_file .git/config.worktree &&
-               test_must_fail git config core.sparseCheckout &&
-               git sparse-checkout set "/*" &&
                test_cmp_config true core.sparseCheckout
        )
 '
@@ -302,8 +300,8 @@ test_expect_success 'revert to old sparse-checkout on empty update' '
                echo >file &&
                git add file &&
                git commit -m "test" &&
-               test_must_fail git sparse-checkout set nothing 2>err &&
-               test_i18ngrep "Sparse checkout leaves no entry on working directory" err &&
+               git sparse-checkout set nothing 2>err &&
+               test_i18ngrep ! "Sparse checkout leaves no entry on working directory" err &&
                test_i18ngrep ! ".git/index.lock" err &&
                git sparse-checkout set file
        )

diff --git a/unpack-trees.c b/unpack-trees.c
index b43f3e775ad858f16f14078e798ea5718316bf49..9a3ccd9d0837a6c5d8826ac00a251911e95a43c9 100644 (file)
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -1677,8 +1677,6 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
        }
 
        if (!o->skip_sparse_checkout) {
-               int empty_worktree = 1;
-
                /*
                 * Sparse checkout loop #2: set NEW_SKIP_WORKTREE on entries not in loop #1
                 * If they will have NEW_SKIP_WORKTREE, also set CE_SKIP_WORKTREE
@@ -1706,19 +1704,6 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 
                        if (apply_sparse_checkout(&o->result, ce, o))
                                ret = 1;
-
-                       if (!ce_skip_worktree(ce))
-                               empty_worktree = 0;
-               }
-               /*
-                * Sparse checkout is meant to narrow down checkout area
-                * but it does not make sense to narrow down to empty working
-                * tree. This is usually a mistake in sparse checkout rules.
-                * Do not allow users to do that.
-                */
-               if (o->result.cache_nr && empty_worktree) {
-                       ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
-                       goto done;
                }
                if (ret == 1) {
                        /*
@@ -1779,7 +1764,7 @@ enum update_sparsity_result update_sparsity(struct unpack_trees_options *o)
 {
        enum update_sparsity_result ret = UPDATE_SPARSITY_SUCCESS;
        struct pattern_list pl;
-       int i, empty_worktree;
+       int i;
        unsigned old_show_all_errors;
        int free_pattern_list = 0;
 
@@ -1810,7 +1795,6 @@ enum update_sparsity_result update_sparsity(struct unpack_trees_options *o)
 
        /* Then loop over entries and update/remove as needed */
        ret = UPDATE_SPARSITY_SUCCESS;
-       empty_worktree = 1;
        for (i = 0; i < o->src_index->cache_nr; i++) {
                struct cache_entry *ce = o->src_index->cache[i];
 
@@ -1824,28 +1808,12 @@ enum update_sparsity_result update_sparsity(struct unpack_trees_options *o)
 
                if (apply_sparse_checkout(o->src_index, ce, o))
                        ret = UPDATE_SPARSITY_WARNINGS;
-
-               if (!ce_skip_worktree(ce))
-                       empty_worktree = 0;
-       }
-
-       /*
-        * Sparse checkout is meant to narrow down checkout area
-        * but it does not make sense to narrow down to empty working
-        * tree. This is usually a mistake in sparse checkout rules.
-        * Do not allow users to do that.
-        */
-       if (o->src_index->cache_nr && empty_worktree) {
-               unpack_failed(o, "Sparse checkout leaves no entry on working directory");
-               ret = UPDATE_SPARSITY_INDEX_UPDATE_FAILURES;
-               goto done;
        }
 
 skip_sparse_checkout:
        if (check_updates(o, o->src_index))
                ret = UPDATE_SPARSITY_WORKTREE_UPDATE_FAILURES;
 
-done:
        display_warning_msgs(o);
        o->show_all_errors = old_show_all_errors;
        if (free_pattern_list)