fixed bug in copy

Author: Priya Wadhwa

integration_tests/dockerfiles/Dockerfile_test_multistage

@@ -2,7 +2,8 @@ FROM gcr.io/distroless/base:latest
 COPY . .
 
 FROM scratch as second
-COPY --from=0 context/foo /foo
+ENV foopath context/foo
+COPY --from=0 $foopath context/b* /foo/
 
 FROM gcr.io/distroless/base:latest
 COPY --from=second /foo /foo2

pkg/commands/copy.go

@@ -73,7 +73,8 @@ func (c *CopyCommand) ExecuteCommand(config *manifest.Schema2Config) error {
 		}
 		if fi.IsDir() {
 			if !filepath.IsAbs(dest) {
-				dest = filepath.Join(cwd, dest)
+				// we need to add '/' to the end to indicate the destination is a directory
+				dest = filepath.Join(cwd, dest) + "/"
 			}
 			if err := util.CopyDir(fullPath, dest); err != nil {
 				return err

pkg/dockerfile/dockerfile.go

@@ -42,7 +42,7 @@ func Parse(b []byte) ([]instructions.Stage, error) {
 	return stages, err
 }
 
-// ResolveStages resolves any calls to previous stages to the number value of that stage
+// ResolveStages resolves any calls to previous stages with names to indices
 // Ex. --from=second_stage should be --from=1 for easier processing later on
 func ResolveStages(stages []instructions.Stage) {
 	nameToIndex := make(map[string]string)

pkg/util/fs_util.go

@@ -144,6 +144,9 @@ func RelativeFiles(fp string, root string) ([]string, error) {
 	fullPath := filepath.Join(root, fp)
 	logrus.Debugf("Getting files and contents at root %s", fullPath)
 	err := filepath.Walk(fullPath, func(path string, info os.FileInfo, err error) error {
+		if PathInWhitelist(path, root) {
+			return nil
+		}
 		if err != nil {
 			return err
 		}