From f2eae0bde91b01f5501e64d2157c1e7770cb7196 Mon Sep 17 00:00:00 2001
From: Nalin Dahyabhai <nalin@redhat.com>
Date: Wed, 31 Mar 2021 17:48:28 -0400
Subject: [PATCH] COPY: treat sources named "" as "*"

If a source for COPY is "", treat it as though it were "*".

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
---
 dockerclient/client.go                      |  3 +++
 dockerclient/conformance_test.go            | 10 ++++++++++
 dockerclient/testdata/copyempty/.script     |  2 ++
 dockerclient/testdata/copyempty/Dockerfile  |  2 ++
 dockerclient/testdata/copyempty/Dockerfile2 |  2 ++
 dockerclient/testdata/copyempty/script1     |  2 ++
 dockerclient/testdata/copyempty/script2     |  2 ++
 7 files changed, 23 insertions(+)
 create mode 100644 dockerclient/testdata/copyempty/.script
 create mode 100644 dockerclient/testdata/copyempty/Dockerfile
 create mode 100644 dockerclient/testdata/copyempty/Dockerfile2
 create mode 100644 dockerclient/testdata/copyempty/script1
 create mode 100644 dockerclient/testdata/copyempty/script2

diff --git a/dockerclient/client.go b/dockerclient/client.go
index 0173b365b..803ec7148 100644
--- a/dockerclient/client.go
+++ b/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
diff --git a/dockerclient/conformance_test.go b/dockerclient/conformance_test.go
index f7d890630..e20262d73 100644
--- a/dockerclient/conformance_test.go
+++ b/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",
diff --git a/dockerclient/testdata/copyempty/.script b/dockerclient/testdata/copyempty/.script
new file mode 100644
index 000000000..f52d05771
--- /dev/null
+++ b/dockerclient/testdata/copyempty/.script
@@ -0,0 +1,2 @@
+#!/bin/bash
+:
\ No newline at end of file
diff --git a/dockerclient/testdata/copyempty/Dockerfile b/dockerclient/testdata/copyempty/Dockerfile
new file mode 100644
index 000000000..8b8c87ede
--- /dev/null
+++ b/dockerclient/testdata/copyempty/Dockerfile
@@ -0,0 +1,2 @@
+FROM centos:7
+COPY "" /usr/local/tmp/
diff --git a/dockerclient/testdata/copyempty/Dockerfile2 b/dockerclient/testdata/copyempty/Dockerfile2
new file mode 100644
index 000000000..b99b8adc3
--- /dev/null
+++ b/dockerclient/testdata/copyempty/Dockerfile2
@@ -0,0 +1,2 @@
+FROM centos:7
+COPY script1 "" script2 /usr/local/tmp/
diff --git a/dockerclient/testdata/copyempty/script1 b/dockerclient/testdata/copyempty/script1
new file mode 100644
index 000000000..c3c3f3f53
--- /dev/null
+++ b/dockerclient/testdata/copyempty/script1
@@ -0,0 +1,2 @@
+#!/bin/bash
+exit 0
\ No newline at end of file
diff --git a/dockerclient/testdata/copyempty/script2 b/dockerclient/testdata/copyempty/script2
new file mode 100644
index 000000000..80f336a03
--- /dev/null
+++ b/dockerclient/testdata/copyempty/script2
@@ -0,0 +1,2 @@
+#!/bin/bash
+exit 1
\ No newline at end of file