unpack-trees: only clear CE_UPDATE|CE_REMOVE when skip-worktree is always set

The purpose of this clearing is, as explained in comment, because
verify_*() may set those bits before apply_sparse_checkout() is
called. By that time, it's not clear whether an entry will stay in
checkout area or out. After $GIT_DIR/info/sparse-checkout is applied,
we know what entries will be in finally. It's time to clean unwanted
bits.

That works perfectly when checkout area remains unchanged. When
checkout area changes, apply_sparse_checkout() may set CE_UPDATE
or CE_WT_REMOVE to widen/narrow checkout area. Doing the clearing
after apply_sparse_checkout() may clear those widening/narrowing
bits unexpectedly.

So, only do that on entries that are not affected by checkout area
changes (i.e. skip-worktree bit does not change after
apply_sparse_checkout).

This code does not actually fix anything though, just
future-proof. The removed code and the narrow/widen code inside
apply_sparse_checkout are currently independent (narrow code never
sets CE_REMOVE, widen code sets CE_UPDATE, but ce_skip_worktree()
would be false).

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.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 9189de8461825bec601760415fa6e5a9c8fc14c1..81ab4c6f37575328d105446a9c619f64b80cc8d7 100755 (executable)
--- a/t/t1011-read-tree-sparse-checkout.sh
+++ b/t/t1011-read-tree-sparse-checkout.sh
@@ -155,4 +155,16 @@ test_expect_success 'read-tree adds to worktree, dirty case' '
        grep -q dirty sub/added
 '
 
+test_expect_success 'index removal and worktree narrowing at the same time' '
+       >empty &&
+       echo init.t >.git/info/sparse-checkout &&
+       echo sub/added >>.git/info/sparse-checkout &&
+       git checkout -f top &&
+       echo init.t >.git/info/sparse-checkout &&
+       git checkout removed &&
+       git ls-files sub/added >result &&
+       test ! -f sub/added &&
+       test_cmp empty result
+'
+
 test_done

diff --git a/unpack-trees.c b/unpack-trees.c
index 75f54cac97f62ddaad736c2cd582cc6cdeaaebfa..ae5e6bff52f86a8299a9cd9c039de0e3194ccb5a 100644 (file)
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -164,13 +164,18 @@ static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_opt
                ce->ce_flags &= ~CE_SKIP_WORKTREE;
 
        /*
-        * We only care about files getting into the checkout area
-        * If merge strategies want to remove some, go ahead, this
-        * flag will be removed eventually in unpack_trees() if it's
-        * outside checkout area.
+        * if (!was_skip_worktree && !ce_skip_worktree()) {
+        *      This is perfectly normal. Move on;
+        * }
         */
-       if (ce->ce_flags & CE_REMOVE)
-               return 0;
+
+       /*
+        * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
+        * area as a result of ce_skip_worktree() shortcuts in
+        * verify_absent() and verify_uptodate(). Clear them.
+        */
+       if (was_skip_worktree && ce_skip_worktree(ce))
+               ce->ce_flags &= ~(CE_UPDATE | CE_REMOVE);
 
        if (!was_skip_worktree && ce_skip_worktree(ce)) {
                /*
@@ -796,14 +801,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
                                ret = -1;
                                goto done;
                        }
-                       /*
-                        * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
-                        * area as a result of ce_skip_worktree() shortcuts in
-                        * verify_absent() and verify_uptodate(). Clear them.
-                        */
-                       if (ce_skip_worktree(ce))
-                               ce->ce_flags &= ~(CE_UPDATE | CE_REMOVE);
-                       else
+                       if (!ce_skip_worktree(ce))
                                empty_worktree = 0;
 
                }