@@ -368,7 +368,9 @@ func run(req dispatchRequest) error {

 		saveCmd = prependEnvOnCmd(req.builder.buildArgs, buildArgs, cmdFromArgs)

 	}

-	runConfigForCacheProbe := copyRunConfig(req.runConfig, withCmd(saveCmd))

+	runConfigForCacheProbe := copyRunConfig(req.runConfig,

+		withCmd(saveCmd),

+		withEntrypointOverride(saveCmd, nil))

 	hit, err := req.builder.probeCache(req.builder.image, runConfigForCacheProbe)

 	if err != nil || hit {

 		return err

@@ -376,18 +378,13 @@ func run(req dispatchRequest) error {

 	runConfig := copyRunConfig(req.runConfig,

 		withCmd(cmdFromArgs),

-		withEnv(append(req.runConfig.Env, buildArgs...)))

+		withEnv(append(req.runConfig.Env, buildArgs...)),

+		withEntrypointOverride(saveCmd, strslice.StrSlice{""}))

 	// set config as already being escaped, this prevents double escaping on windows

 	runConfig.ArgsEscaped = true

 	logrus.Debugf("[BUILDER] Command to be executed: %v", runConfig.Cmd)

-

-	// Set blank entrypoint to cancel the entrypoint from the parent image

-	if len(runConfig.Cmd) > 0 {

-		runConfig.Entrypoint = strslice.StrSlice{""}

-	}

-

 	cID, err := req.builder.create(runConfig)

 	if err != nil {

 		return err

@@ -65,7 +65,8 @@ func (b *Builder) commitContainer(id string, containerConfig *container.Config)

 		ContainerCommitConfig: types.ContainerCommitConfig{

 			Author: b.maintainer,

 			Pause:  true,

-			Config: b.runConfig,

+			// TODO: this should be done by Commit()

+			Config: copyRunConfig(b.runConfig),

 		},

 		ContainerConfig: containerConfig,

 	}

@@ -233,6 +234,21 @@ func withEnv(env []string) runConfigModifier {

 	}

 }

+// withEntrypointOverride sets an entrypoint on runConfig if the command is

+// not empty. The entrypoint is left unmodified if command is empty.

+//

+// The dockerfile RUN instruction expect to run without an entrypoint

+// so the runConfig entrypoint needs to be modified accordingly. ContainerCreate

+// will change a []string{""} entrypoint to nil, so we probe the cache with the

+// nil entrypoint.

+func withEntrypointOverride(cmd []string, entrypoint []string) runConfigModifier {

+	return func(runConfig *container.Config) {

+		if len(cmd) > 0 {

+			runConfig.Entrypoint = entrypoint

+		}

+	}

+}

+

 // getShell is a helper function which gets the right shell for prefixing the

 // shell-form of RUN, ENTRYPOINT and CMD instructions

 func getShell(c *container.Config) []string {

@@ -1785,11 +1785,17 @@ func (s *DockerSuite) TestBuildConditionalCache(c *check.C) {

 	}

 }

-// FIXME(vdemeester) this really seems to test the same thing as before

 func (s *DockerSuite) TestBuildAddMultipleLocalFileWithAndWithoutCache(c *check.C) {

 	name := "testbuildaddmultiplelocalfilewithcache"

-	dockerfile := `

+	baseName := name + "-base"

+

+	cli.BuildCmd(c, baseName, build.WithDockerfile(`

 		FROM busybox

+		ENTRYPOINT ["/bin/sh"]

+	`))

+

+	dockerfile := `

+		FROM testbuildaddmultiplelocalfilewithcache-base

         MAINTAINER dockerio

         ADD foo Dockerfile /usr/lib/bla/

 		RUN sh -c "[ $(cat /usr/lib/bla/foo) = "hello" ]"`

@@ -1799,15 +1805,15 @@ func (s *DockerSuite) TestBuildAddMultipleLocalFileWithAndWithoutCache(c *check.

 	defer ctx.Close()

 	cli.BuildCmd(c, name, build.WithExternalBuildContext(ctx))

 	id1 := getIDByName(c, name)

-	cli.BuildCmd(c, name, build.WithExternalBuildContext(ctx))

+	result2 := cli.BuildCmd(c, name, build.WithExternalBuildContext(ctx))

 	id2 := getIDByName(c, name)

-	cli.BuildCmd(c, name, build.WithoutCache, build.WithExternalBuildContext(ctx))

+	result3 := cli.BuildCmd(c, name, build.WithoutCache, build.WithExternalBuildContext(ctx))

 	id3 := getIDByName(c, name)

 	if id1 != id2 {

-		c.Fatal("The cache should have been used but hasn't.")

+		c.Fatalf("The cache should have been used but hasn't: %s", result2.Stdout())

 	}

 	if id1 == id3 {

-		c.Fatal("The cache should have been invalided but hasn't.")

+		c.Fatalf("The cache should have been invalided but hasn't: %s", result3.Stdout())

 	}

 }