8 files changed, 55 insertions, 17 deletions
diff --git a/utils/merkletrie/difftree.go b/utils/merkletrie/difftree.go
index bd084b2..9f5145a 100644
--- a/utils/merkletrie/difftree.go
+++ b/utils/merkletrie/difftree.go
@@ -304,13 +304,38 @@ func DiffTreeContext(ctx context.Context, fromTree, toTree noder.Noder,
 				return nil, err
 			}
 		case onlyToRemains:
-			if err = ret.AddRecursiveInsert(to); err != nil {
-				return nil, err
+			if to.Skip() {
+				if err = ret.AddRecursiveDelete(to); err != nil {
+					return nil, err
+				}
+			} else {
+				if err = ret.AddRecursiveInsert(to); err != nil {
+					return nil, err
+				}
 			}
 			if err = ii.nextTo(); err != nil {
 				return nil, err
 			}
 		case bothHaveNodes:
+			if from.Skip() {
+				if err = ret.AddRecursiveDelete(from); err != nil {
+					return nil, err
+				}
+				if err := ii.nextBoth(); err != nil {
+					return nil, err
+				}
+				break
+			}
+			if to.Skip() {
+				if err = ret.AddRecursiveDelete(to); err != nil {
+					return nil, err
+				}
+				if err := ii.nextBoth(); err != nil {
+					return nil, err
+				}
+				break
+			}
+
 			if err = diffNodes(&ret, ii); err != nil {
 				return nil, err
 			}
diff --git a/utils/merkletrie/filesystem/node.go b/utils/merkletrie/filesystem/node.go
index 2fc3d7a..ad169ff 100644
--- a/utils/merkletrie/filesystem/node.go
+++ b/utils/merkletrie/filesystem/node.go
@@ -61,6 +61,10 @@ func (n *node) IsDir() bool {
 	return n.isDir
 }
 
+func (n *node) Skip() bool {
+	return false
+}
+
 func (n *node) Children() ([]noder.Noder, error) {
 	if err := n.calculateChildren(); err != nil {
 		return nil, err
diff --git a/utils/merkletrie/index/node.go b/utils/merkletrie/index/node.go
index d05b0c6..c1809f7 100644
--- a/utils/merkletrie/index/node.go
+++ b/utils/merkletrie/index/node.go
@@ -19,6 +19,7 @@ type node struct {
 	entry    *index.Entry
 	children []noder.Noder
 	isDir    bool
+	skip     bool
 }
 
 // NewRootNode returns the root node of a computed tree from a index.Index,
@@ -39,7 +40,7 @@ func NewRootNode(idx *index.Index) noder.Noder {
 				continue
 			}
 
-			n := &node{path: fullpath}
+			n := &node{path: fullpath, skip: e.SkipWorktree}
 			if fullpath == e.Name {
 				n.entry = e
 			} else {
@@ -58,6 +59,10 @@ func (n *node) String() string {
 	return n.path
 }
 
+func (n *node) Skip() bool {
+	return n.skip
+}
+
 // Hash the hash of a filesystem is a 24-byte slice, is the result of
 // concatenating the computed plumbing.Hash of the file as a Blob and its
 // plumbing.FileMode; that way the difftree algorithm will detect changes in the
diff --git a/utils/merkletrie/internal/fsnoder/dir.go b/utils/merkletrie/internal/fsnoder/dir.go
index 20a2aee..3a4c242 100644
--- a/utils/merkletrie/internal/fsnoder/dir.go
+++ b/utils/merkletrie/internal/fsnoder/dir.go
@@ -112,6 +112,10 @@ func (d *dir) NumChildren() (int, error) {
 	return len(d.children), nil
 }
 
+func (d *dir) Skip() bool {
+	return false
+}
+
 const (
 	dirStartMark  = '('
 	dirEndMark    = ')'
diff --git a/utils/merkletrie/internal/fsnoder/file.go b/utils/merkletrie/internal/fsnoder/file.go
index d53643f..0bb908b 100644
--- a/utils/merkletrie/internal/fsnoder/file.go
+++ b/utils/merkletrie/internal/fsnoder/file.go
@@ -55,6 +55,10 @@ func (f *file) NumChildren() (int, error) {
 	return 0, nil
 }
 
+func (f *file) Skip() bool {
+	return false
+}
+
 const (
 	fileStartMark = '<'
 	fileEndMark   = '>'
diff --git a/utils/merkletrie/noder/noder.go b/utils/merkletrie/noder/noder.go
index d6b3de4..6d22b8c 100644
--- a/utils/merkletrie/noder/noder.go
+++ b/utils/merkletrie/noder/noder.go
@@ -53,6 +53,7 @@ type Noder interface {
 	// implement NumChildren in O(1) while Children is usually more
 	// complex.
 	NumChildren() (int, error)
+	Skip()	bool
 }
 
 // NoChildren represents the children of a noder without children.
diff --git a/utils/merkletrie/noder/noder_test.go b/utils/merkletrie/noder/noder_test.go
index 5e014fe..c1af998 100644
--- a/utils/merkletrie/noder/noder_test.go
+++ b/utils/merkletrie/noder/noder_test.go
@@ -25,6 +25,7 @@ func (n noderMock) Name() string               { return n.name }
 func (n noderMock) IsDir() bool                { return n.isDir }
 func (n noderMock) Children() ([]Noder, error) { return n.children, nil }
 func (n noderMock) NumChildren() (int, error)  { return len(n.children), nil }
+func (n noderMock) Skip() bool                 { return false }
 
 // Returns a sequence with the noders 3, 2, and 1 from the
 // following diagram:
@@ -57,20 +58,6 @@ func childrenFixture() []Noder {
 	return []Noder{c1, c2}
 }
 
-// Returns the same as nodersFixture but sorted by name, this is: "1",
-// "2" and then "3".
-func sortedNodersFixture() []Noder {
-	n1 := &noderMock{
-		name:     "1",
-		hash:     []byte{0x00, 0x01, 0x02},
-		isDir:    true,
-		children: childrenFixture(),
-	}
-	n2 := &noderMock{name: "2"}
-	n3 := &noderMock{name: "3"}
-	return []Noder{n1, n2, n3} // the same as nodersFixture but sorted by name
-}
-
 // returns nodersFixture as the path of "1".
 func pathFixture() Path {
 	return Path(nodersFixture())
diff --git a/utils/merkletrie/noder/path.go b/utils/merkletrie/noder/path.go
index 1c7ef54..6c1d363 100644
--- a/utils/merkletrie/noder/path.go
+++ b/utils/merkletrie/noder/path.go
@@ -15,6 +15,14 @@ import (
 // not be used.
 type Path []Noder
 
+func (p Path) Skip() bool {
+	if len(p) > 0 {
+		return p.Last().Skip()
+	}
+
+	return false
+}
+
 // String returns the full path of the final noder as a string, using
 // "/" as the separator.
 func (p Path) String() string {