Add a test for issue #2638.

instrumentation/src/androidTest/java/com/bumptech/glide/Issue2638Test.java

@@ -0,0 +1,80 @@
+package com.bumptech.glide;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.graphics.Bitmap;
+import android.graphics.Bitmap.CompressFormat;
+import android.graphics.BitmapFactory;
+import android.graphics.Color;
+import android.graphics.drawable.BitmapDrawable;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.runner.AndroidJUnit4;
+import android.widget.AbsListView.LayoutParams;
+import android.widget.ImageView;
+import com.bumptech.glide.test.BitmapSubject;
+import com.bumptech.glide.test.ConcurrencyHelper;
+import com.bumptech.glide.test.ResourceIds;
+import com.bumptech.glide.test.TearDownGlide;
+import com.google.common.io.ByteStreams;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.concurrent.ExecutionException;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+public class Issue2638Test {
+  @Rule public final TearDownGlide tearDownGlide = new TearDownGlide();
+  private final ConcurrencyHelper concurrency = new ConcurrencyHelper();
+  private Context context;
+
+  @Before
+  public void setUp() {
+    context = InstrumentationRegistry.getTargetContext();
+  }
+
+  @Test
+  public void intoImageView_withDifferentByteArrays_loadsDifferentImages()
+      throws IOException, ExecutionException, InterruptedException {
+    final ImageView imageView = new ImageView(context);
+    imageView.setLayoutParams(new LayoutParams(/*w=*/ 100, /*h=*/ 100));
+
+    final byte[] canonicalBytes = getCanonicalBytes();
+    final byte[] modifiedBytes = getModifiedBytes();
+
+    Glide.with(context)
+        .load(canonicalBytes)
+        .submit()
+        .get();
+
+    concurrency.loadOnMainThread(Glide.with(context).load(canonicalBytes), imageView);
+    Bitmap firstBitmap = ((BitmapDrawable) imageView.getDrawable()).getBitmap();
+
+    concurrency.loadOnMainThread(Glide.with(context).load(modifiedBytes), imageView);
+    Bitmap secondBitmap = ((BitmapDrawable) imageView.getDrawable()).getBitmap();
+
+    BitmapSubject.assertThat(firstBitmap).isNotSameAs(secondBitmap);
+  }
+
+  private byte[] getModifiedBytes() throws IOException {
+    byte[] canonicalBytes = getCanonicalBytes();
+    BitmapFactory.Options options = new BitmapFactory.Options();
+    options.inMutable = true;
+    Bitmap bitmap =
+        BitmapFactory.decodeByteArray(canonicalBytes, 0, canonicalBytes.length, options);
+    bitmap.setPixel(0, 0, Color.TRANSPARENT);
+    ByteArrayOutputStream os = new ByteArrayOutputStream();
+    bitmap.compress(CompressFormat.PNG, /*quality=*/ 100, os);
+    return os.toByteArray();
+  }
+
+  private byte[] getCanonicalBytes() throws IOException {
+    int resourceId = ResourceIds.raw.canonical;
+    Resources resources = context.getResources();
+    InputStream is = resources.openRawResource(resourceId);
+    return ByteStreams.toByteArray(is);
+  }
+}

instrumentation/src/androidTest/java/com/bumptech/glide/test/BitmapSubject.java

@@ -94,4 +94,10 @@ public void sameAs(Bitmap other) {
       fail("is the same as " + getDisplayString(other));
     }
   }
+
+  public void isNotSameAs(Bitmap other) {
+    if (actual().sameAs(other)) {
+      fail("is not the same as " + getDisplayString(other));
+    }
+  }
 }