From 15d48703fc04625acdee7ddbac59e53b5a29bcaf Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Thu, 12 May 2016 02:00:22 +0900
Subject: [PATCH] graphics: Bug fix: NewImageFromImage with ebiten.Image froze
 (#212)

---
 image.go      |  5 +++
 image_test.go | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 89 insertions(+)
 create mode 100644 image_test.go

diff --git a/image.go b/image.go
index 2a1ab04c8..2a1a5c874 100644
--- a/image.go
+++ b/image.go
@@ -338,6 +338,11 @@ func NewImage(width, height int, filter Filter) (*Image, error) {
 //
 // This function is concurrent-safe.
 func NewImageFromImage(img image.Image, filter Filter) (*Image, error) {
+	// Can't call (*ebiten.Image).At here because of the lock.
+	if _, ok := img.(*Image); ok {
+		return nil, errors.New("ebiten: NewImageFromImage can't take *ebiten.Image")
+	}
+
 	imageM.Lock()
 	defer imageM.Unlock()
 	size := img.Bounds().Size()
diff --git a/image_test.go b/image_test.go
new file mode 100644
index 000000000..918ab8ab9
--- /dev/null
+++ b/image_test.go
@@ -0,0 +1,84 @@
+// Copyright 2016 Hajime Hoshi
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ebiten_test
+
+import (
+	"image"
+	_ "image/png"
+	"testing"
+
+	. "github.com/hajimehoshi/ebiten"
+)
+
+var ebitenImageBin = ""
+
+func openImage(path string) (image.Image, error) {
+	file, err := readFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	img, _, err := image.Decode(file)
+	if err != nil {
+		return nil, err
+	}
+	return img, nil
+}
+
+func openEbitenImage(path string) (*Image, image.Image, error) {
+	img, err := openImage(path)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	eimg, err := NewImageFromImage(img, FilterNearest)
+	if err != nil {
+		return nil, nil, err
+	}
+	return eimg, img, nil
+}
+
+func TestImageSelf(t *testing.T) {
+	img, _, err := openEbitenImage("testdata/ebiten.png")
+	if err != nil {
+		t.Fatal(err)
+		return
+	}
+	if err := img.DrawImage(img, nil); err == nil {
+		t.Fatalf("img.DrawImage(img, nil) doesn't return error; an error should be returned")
+	}
+}
+
+func TestImageDispose(t *testing.T) {
+	img, err := NewImage(16, 16, FilterNearest)
+	if err != nil {
+		t.Fatal(err)
+		return
+	}
+	if err := img.Dispose(); err != nil {
+		t.Errorf("img.Dipose() returns error: %v", err)
+	}
+}
+
+func TestNewImageFromEbitenImage(t *testing.T) {
+	img, _, err := openEbitenImage("testdata/ebiten.png")
+	if err != nil {
+		t.Fatal(err)
+		return
+	}
+	if _, err := NewImageFromImage(img, FilterNearest); err == nil {
+		t.Errorf("NewImageFromImage with an *ebiten.Image must return an error")
+	}
+}