dont process purely whiteout flag files (fixes #30)

filetree/node.go

@@ -44,6 +44,7 @@ func NewNode(parent *FileNode, name string, data FileInfo) (node *FileNode) {
 	if parent != nil {
 		node.Tree = parent.Tree
 	}
+
 	return node
 }
 
@@ -85,6 +86,11 @@ func (node *FileNode) Copy(parent *FileNode) *FileNode {
 
 // AddChild creates a new node relative to the current FileNode.
 func (node *FileNode) AddChild(name string, data FileInfo) (child *FileNode) {
+	// never allow processing of purely whiteout flag files (for now)
+	if strings.HasPrefix(name, doubleWhiteoutPrefix) {
+		return nil
+	}
+
 	child = NewNode(node, name, data)
 	if node.Children[name] != nil {
 		// tree node already exists, replace the payload, keep the children
@@ -93,6 +99,7 @@ func (node *FileNode) AddChild(name string, data FileInfo) (child *FileNode) {
 		node.Children[name] = child
 		node.Tree.Size++
 	}
+
 	return child
 }
 
@@ -229,7 +236,7 @@ func (node *FileNode) IsLeaf() bool {
 // Path returns a slash-delimited string from the root of the greater tree to the current node (e.g. /a/path/to/here)
 func (node *FileNode) Path() string {
 	if node.path == "" {
-		path := []string{}
+		var path []string
 		curNode := node
 		for {
 			if curNode.Parent == nil {

filetree/node_test.go

@@ -95,13 +95,18 @@ func TestIsWhiteout(t *testing.T) {
 	tree1 := NewFileTree()
 	p1, _ := tree1.AddPath("/etc/nginx/public1", FileInfo{})
 	p2, _ := tree1.AddPath("/etc/nginx/.wh.public2", FileInfo{})
+	p3, _ := tree1.AddPath("/etc/nginx/public3/.wh..wh..opq", FileInfo{})
 
 	if p1.IsWhiteout() != false {
-		t.Errorf("Expected Path '%s' to **not** be a whiteout file", p1.Name)
+		t.Errorf("Expected path '%s' to **not** be a whiteout file", p1.Name)
 	}
 
 	if p2.IsWhiteout() != true {
-		t.Errorf("Expected Path '%s' to be a whiteout file", p2.Name)
+		t.Errorf("Expected path '%s' to be a whiteout file", p2.Name)
+	}
+
+	if p3 != nil {
+		t.Errorf("Expected to not be able to add path '%s'", p2.Name)
 	}
 }
 

filetree/tree.go

@@ -3,19 +3,21 @@ package filetree
 import (
 	"fmt"
 	"github.com/satori/go.uuid"
+	"github.com/sirupsen/logrus"
 	"sort"
 	"strings"
 )
 
 const (
-	newLine         = "\n"
-	noBranchSpace   = "    "
-	branchSpace     = "│   "
-	middleItem      = "├─"
-	lastItem        = "└─"
-	whiteoutPrefix  = ".wh."
-	uncollapsedItem = "─ "
-	collapsedItem   = "⊕ "
+	newLine              = "\n"
+	noBranchSpace        = "    "
+	branchSpace          = "│   "
+	middleItem           = "├─"
+	lastItem             = "└─"
+	whiteoutPrefix       = ".wh."
+	doubleWhiteoutPrefix = ".wh..wh.."
+	uncollapsedItem      = "─ "
+	collapsedItem        = "⊕ "
 )
 
 // FileTree represents a set of files, directories, and their relations.
@@ -218,6 +220,11 @@ func (tree *FileTree) AddPath(path string, data FileInfo) (*FileNode, error) {
 			// don't attach the payload. The payload is destined for the
 			// Path's end node, not any intermediary node.
 			node = node.AddChild(name, FileInfo{})
+
+			if node == nil {
+				// the child could not be added
+				return node, fmt.Errorf(fmt.Sprintf("could not add child node '%s'", name))
+			}
 		}
 
 		// attach payload to the last specified node
@@ -277,7 +284,10 @@ func (tree *FileTree) markRemoved(path string) error {
 func StackRange(trees []*FileTree, start, stop int) *FileTree {
 	tree := trees[0].Copy()
 	for idx := start; idx <= stop; idx++ {
-		tree.Stack(trees[idx])
+		err := tree.Stack(trees[idx])
+		if err != nil {
+			logrus.Debug("could not stack tree range:", err)
+		}
 	}
 
 	return tree

filetree/tree_test.go

@@ -187,6 +187,8 @@ func TestStack(t *testing.T) {
 	// whiteout the following files
 	tree2.AddPath("/var/run/.wh.bashful", FileInfo{})
 	tree2.AddPath("/.wh.tmp", FileInfo{})
+	// ignore opaque whiteout files entirely
+	tree2.AddPath("/.wh..wh..opq", FileInfo{})
 
 	err := tree1.Stack(tree2)