COPY: treat sources named "" as "*"

dockerclient/client.go

@@ -936,6 +936,9 @@ func (e *ClientExecutor) CopyContainer(container *docker.Container, excludes []s
 		}
 		// TODO: reuse source
 		for _, src := range c.Src {
+			if src == "" {
+				src = "*"
+			}
 			klog.V(4).Infof("Archiving %s download=%t fromFS=%t from=%s", src, c.Download, c.FromFS, c.From)
 			var r io.Reader
 			var closer io.Closer

dockerclient/conformance_test.go

@@ -269,6 +269,16 @@ func TestConformanceInternal(t *testing.T) {
 			Name:       "copy chown",
 			ContextDir: "testdata/copychown",
 		},
+		{
+			Name:       "copy empty 1",
+			ContextDir: "testdata/copyempty",
+			Dockerfile: "Dockerfile",
+		},
+		{
+			Name:       "copy empty 2",
+			ContextDir: "testdata/copyempty",
+			Dockerfile: "Dockerfile2",
+		},
 		{
 			Name:       "copy dir",
 			ContextDir: "testdata/copydir",

dockerclient/testdata/copyempty/.script

@@ -0,0 +1,2 @@
+#!/bin/bash
+:

dockerclient/testdata/copyempty/Dockerfile

@@ -0,0 +1,2 @@
+FROM centos:7
+COPY "" /usr/local/tmp/

dockerclient/testdata/copyempty/Dockerfile2

@@ -0,0 +1,2 @@
+FROM centos:7
+COPY script1 "" script2 /usr/local/tmp/

dockerclient/testdata/copyempty/script1

@@ -0,0 +1,2 @@
+#!/bin/bash
+exit 0

dockerclient/testdata/copyempty/script2

@@ -0,0 +1,2 @@
+#!/bin/bash
+exit 1