From 42b1ea4889cd61790f81001ada5deac9354be378 Mon Sep 17 00:00:00 2001
From: "Guillaume J. Charmes" <guillaume.charmes@dotcloud.com>
Date: Tue, 7 May 2013 11:18:13 -0700
Subject: [PATCH] Check the command existance prior create and add Unit tests
 for the case

---
 builder.go      |  2 +-
 runtime.go      |  4 ++++
 runtime_test.go | 25 ++++++++++++++++++++++++-
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/builder.go b/builder.go
index e835c6d390..d8a22ac3c8 100644
--- a/builder.go
+++ b/builder.go
@@ -72,7 +72,7 @@ func (builder *Builder) Create(config *Config) (*Container, error) {
 		builder.mergeConfig(config, img.Config)
 	}
 
-	if config.Cmd == nil {
+	if config.Cmd == nil || len(config.Cmd) == 0 {
 		return nil, fmt.Errorf("No command specified")
 	}
 
diff --git a/runtime.go b/runtime.go
index 5958aa1811..7db3b40325 100644
--- a/runtime.go
+++ b/runtime.go
@@ -178,6 +178,10 @@ func (runtime *Runtime) LogToDisk(src *writeBroadcaster, dst string) error {
 }
 
 func (runtime *Runtime) Destroy(container *Container) error {
+	if container == nil {
+		return fmt.Errorf("The given container is <nil>")
+	}
+
 	element := runtime.getContainerElement(container.Id)
 	if element == nil {
 		return fmt.Errorf("Container %v not found - maybe it was already destroyed?", container.Id)
diff --git a/runtime_test.go b/runtime_test.go
index 8e21f57bc5..68e1213497 100644
--- a/runtime_test.go
+++ b/runtime_test.go
@@ -118,7 +118,10 @@ func TestRuntimeCreate(t *testing.T) {
 	if len(runtime.List()) != 0 {
 		t.Errorf("Expected 0 containers, %v found", len(runtime.List()))
 	}
-	container, err := NewBuilder(runtime).Create(&Config{
+
+	builder := NewBuilder(runtime)
+
+	container, err := builder.Create(&Config{
 		Image: GetTestImage(runtime).Id,
 		Cmd:   []string{"ls", "-al"},
 	},
@@ -157,6 +160,26 @@ func TestRuntimeCreate(t *testing.T) {
 	if !runtime.Exists(container.Id) {
 		t.Errorf("Exists() returned false for a newly created container")
 	}
+
+	// Make sure crete with bad parameters returns an error
+	_, err = builder.Create(
+		&Config{
+			Image: GetTestImage(runtime).Id,
+		},
+	)
+	if err == nil {
+		t.Fatal("Builder.Create should throw an error when Cmd is missing")
+	}
+
+	_, err = builder.Create(
+		&Config{
+			Image: GetTestImage(runtime).Id,
+			Cmd:   []string{},
+		},
+	)
+	if err == nil {
+		t.Fatal("Builder.Create should throw an error when Cmd is empty")
+	}
 }
 
 func TestDestroy(t *testing.T) {