@@ -588,6 +588,7 @@ func TestBuildRm(t *testing.T) {

 	logDone("build - ensure --rm doesn't leave containers behind and that --rm=true is the default")

 	logDone("build - ensure --rm=false overrides the default")

 }

+

 func TestBuildWithVolumes(t *testing.T) {

 	name := "testbuildvolumes"

 	expected := "map[/test1:map[] /test2:map[]]"

@@ -766,6 +767,68 @@ func TestBuildEntrypoint(t *testing.T) {

 	logDone("build - entrypoint")

 }

+// #6445 ensure ONBUILD triggers aren't committed to grandchildren

+func TestBuildOnBuildLimitedInheritence(t *testing.T) {

+	name1 := "testonbuildtrigger1"

+	dockerfile1 := `

+		FROM busybox

+		RUN echo "GRANDPARENT"

+		ONBUILD RUN echo "ONBUILD PARENT"

+	`

+	ctx1, err := fakeContext(dockerfile1, nil)

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	buildCmd := exec.Command(dockerBinary, "build", "-t", name1, ".")

+	buildCmd.Dir = ctx1.Dir

+	out1, _, err := runCommandWithOutput(buildCmd)

+	errorOut(err, t, fmt.Sprintf("build failed to complete: %v %v", out1, err))

+	defer deleteImages(name1)

+

+	name2 := "testonbuildtrigger2"

+	dockerfile2 := `

+		FROM testonbuildtrigger1

+	`

+	ctx2, err := fakeContext(dockerfile2, nil)

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	buildCmd = exec.Command(dockerBinary, "build", "-t", name2, ".")

+	buildCmd.Dir = ctx2.Dir

+	out2, _, err := runCommandWithOutput(buildCmd)

+	errorOut(err, t, fmt.Sprintf("build failed to complete: %v %v", out2, err))

+	defer deleteImages(name2)

+

+	name3 := "testonbuildtrigger3"

+	dockerfile3 := `

+		FROM testonbuildtrigger2

+	`

+	ctx3, err := fakeContext(dockerfile3, nil)

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	buildCmd = exec.Command(dockerBinary, "build", "-t", name3, ".")

+	buildCmd.Dir = ctx3.Dir

+	out3, _, err := runCommandWithOutput(buildCmd)

+	errorOut(err, t, fmt.Sprintf("build failed to complete: %v %v", out3, err))

+	defer deleteImages(name3)

+

+	// ONBUILD should be run in second build.

+	if !strings.Contains(out2, "ONBUILD PARENT") {

+		t.Fatalf("ONBUILD instruction did not run in child of ONBUILD parent")

+	}

+

+	// ONBUILD should *not* be run in third build.

+	if strings.Contains(out3, "ONBUILD PARENT") {

+		t.Fatalf("ONBUILD instruction ran in grandchild of ONBUILD parent")

+	}

+

+	logDone("build - onbuild")

+}

+

 func TestBuildWithCache(t *testing.T) {

 	name := "testbuildwithcache"

 	defer deleteImages(name)

@@ -123,7 +123,12 @@ func (b *buildFile) CmdFrom(name string) error {

 	if nTriggers := len(b.config.OnBuild); nTriggers != 0 {

 		fmt.Fprintf(b.errStream, "# Executing %d build triggers\n", nTriggers)

 	}

-	for n, step := range b.config.OnBuild {

+

+	// Copy the ONBUILD triggers, and remove them from the config, since the config will be commited.

+	onBuildTriggers := b.config.OnBuild

+	b.config.OnBuild = []string{}

+

+	for n, step := range onBuildTriggers {

 		splitStep := strings.Split(step, " ")

 		stepInstruction := strings.ToUpper(strings.Trim(splitStep[0], " "))

 		switch stepInstruction {

@@ -136,7 +141,6 @@ func (b *buildFile) CmdFrom(name string) error {

 			return err

 		}

 	}

-	b.config.OnBuild = []string{}

 	return nil

 }