Merge branch 'vd/sparse-read-tree'

"git read-tree" has been made to be aware of the sparse-index
feature.

* vd/sparse-read-tree:
  read-tree: make three-way merge sparse-aware
  read-tree: make two-way merge sparse-aware
  read-tree: narrow scope of index expansion for '--prefix'
  read-tree: integrate with sparse index
  read-tree: expand sparse checkout test coverage
  read-tree: explicitly disallow prefixes with a leading '/'
  status: fix nested sparse directory diff in sparse index
  sparse-index: prevent repo root from becoming sparse

1 files changed, 4 insertions, 3 deletions

diff --git a/dir.c b/dir.c
index 3b37022720..f2b0f24210 100644
--- a/dir.c
+++ b/dir.c
@@ -1463,10 +1463,11 @@ static int path_in_sparse_checkout_1(const char *path,
 	const char *end, *slash;
 
 	/*
-	 * We default to accepting a path if there are no patterns or
-	 * they are of the wrong type.
+	 * We default to accepting a path if the path is empty, there are no
+	 * patterns, or the patterns are of the wrong type.
 	 */
-	if (init_sparse_checkout_patterns(istate) ||
+	if (!*path ||
+	    init_sparse_checkout_patterns(istate) ||
 	    (require_cone_mode &&
 	     !istate->sparse_checkout_patterns->use_cone_patterns))
 		return 1;