2 files changed, 24 insertions, 6 deletions

diff --git a/src/cmd/pack/pack.go b/src/cmd/pack/pack.go
index 99e22ed7ea..7276083264 100644
--- a/src/cmd/pack/pack.go
+++ b/src/cmd/pack/pack.go
@@ -132,9 +132,10 @@ const (
 // An Archive represents an open archive file. It is always scanned sequentially
 // from start to end, without backing up.
 type Archive struct {
-	fd    *os.File // Open file descriptor.
-	files []string // Explicit list of files to be processed.
-	pad   int      // Padding bytes required at end of current archive file
+	fd       *os.File // Open file descriptor.
+	files    []string // Explicit list of files to be processed.
+	pad      int      // Padding bytes required at end of current archive file
+	matchAll bool     // match all files in archive
 }
 
 // archive opens (or if necessary creates) the named archive.
@@ -148,8 +149,9 @@ func archive(name string, mode int, files []string) *Archive {
 	}
 	mustBeArchive(fd)
 	return &Archive{
-		fd:    fd,
-		files: files,
+		fd:       fd,
+		files:    files,
+		matchAll: len(files) == 0,
 	}
 }
 
@@ -282,7 +284,7 @@ func (ar *Archive) skip(entry *Entry) {
 // match reports whether the entry matches the argument list.
 // If it does, it also drops the file from the to-be-processed list.
 func (ar *Archive) match(entry *Entry) bool {
-	if len(ar.files) == 0 {
+	if ar.matchAll {
 		return true
 	}
 	for i, name := range ar.files {
diff --git a/src/cmd/pack/pack_test.go b/src/cmd/pack/pack_test.go
index b54b0ae432..33abe45a20 100644
--- a/src/cmd/pack/pack_test.go
+++ b/src/cmd/pack/pack_test.go
@@ -90,10 +90,12 @@ func TestTableOfContents(t *testing.T) {
 	defer os.RemoveAll(dir)
 	name := filepath.Join(dir, "pack.a")
 	ar := archive(name, os.O_RDWR, nil)
+
 	// Add some entries by hand.
 	ar.addFile(helloFile.Reset())
 	ar.addFile(goodbyeFile.Reset())
 	ar.fd.Close()
+
 	// Now print it.
 	ar = archive(name, os.O_RDONLY, nil)
 	var buf bytes.Buffer
@@ -111,6 +113,7 @@ func TestTableOfContents(t *testing.T) {
 	if result != expect {
 		t.Fatalf("expected %q got %q", expect, result)
 	}
+
 	// Do it again without verbose.
 	verbose = false
 	buf.Reset()
@@ -123,6 +126,19 @@ func TestTableOfContents(t *testing.T) {
 	if result != expect {
 		t.Fatalf("expected %q got %q", expect, result)
 	}
+
+	// Do it again with file list arguments.
+	verbose = false
+	buf.Reset()
+	ar = archive(name, os.O_RDONLY, []string{helloFile.name})
+	ar.scan(ar.tableOfContents)
+	ar.fd.Close()
+	result = buf.String()
+	// Expect only helloFile.
+	expect = fmt.Sprintf("%s\n", helloFile.name)
+	if result != expect {
+		t.Fatalf("expected %q got %q", expect, result)
+	}
 }
 
 // Test that we can create an archive, put some files in it, and get back a file.