use WithOverwriteWithEmptyValue to support merging boolean pointers

Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>

loader/merge.go

@@ -113,7 +113,11 @@ func mergeServices(base, override []types.ServiceConfig) ([]types.ServiceConfig,
 }
 
 func _merge(baseService *types.ServiceConfig, overrideService *types.ServiceConfig) (*types.ServiceConfig, error) {
-	if err := mergo.Merge(baseService, overrideService, mergo.WithAppendSlice, mergo.WithOverride, mergo.WithTransformers(serviceSpecials)); err != nil {
+	if err := mergo.Merge(baseService, overrideService,
+		mergo.WithAppendSlice,
+		mergo.WithOverride,
+		mergo.WithOverwriteWithEmptyValue,
+		mergo.WithTransformers(serviceSpecials)); err != nil {
 		return nil, err
 	}
 	if overrideService.Command != nil {

loader/merge_test.go

@@ -1110,6 +1110,22 @@ func TestMergeUlimitsConfig(t *testing.T) {
 	)
 }
 
+func TestInitOverride(t *testing.T) {
+	var (
+		bt = true
+		bf = false
+	)
+	base := types.ServiceConfig{
+		Init: &bt,
+	}
+	override := types.ServiceConfig{
+		Init: &bf,
+	}
+	config, err := _merge(&base, &override)
+	assert.NilError(t, err)
+	assert.Check(t, *config.Init == false)
+}
+
 func TestMergeServiceNetworkConfig(t *testing.T) {
 	specials := &specials{
 		m: map[reflect.Type]func(dst, src reflect.Value) error{