From 4afa934251aa0fb1bb56ef66ab87a1ce327ac6b4 Mon Sep 17 00:00:00 2001
From: Harald Kuhr <harald.kuhr@gmail.com>
Date: Sat, 18 Aug 2018 13:12:54 +0200
Subject: [PATCH] #431: Clean-up + added test

---
 .../plugins/pict/PICTImageReaderSpi.java        |  7 +++----
 .../plugins/pict/PICTImageReaderTest.java       | 17 +++++++++++++++++
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/imageio/imageio-pict/src/main/java/com/twelvemonkeys/imageio/plugins/pict/PICTImageReaderSpi.java b/imageio/imageio-pict/src/main/java/com/twelvemonkeys/imageio/plugins/pict/PICTImageReaderSpi.java
index c19d1d8b..2846a9ad 100755
--- a/imageio/imageio-pict/src/main/java/com/twelvemonkeys/imageio/plugins/pict/PICTImageReaderSpi.java
+++ b/imageio/imageio-pict/src/main/java/com/twelvemonkeys/imageio/plugins/pict/PICTImageReaderSpi.java
@@ -70,9 +70,8 @@ public final class PICTImageReaderSpi extends ImageReaderSpiBase {
                 // Skip header 512 bytes for file-based streams
                 stream.reset();
 
-                // If we don't mark again here, the reset call in the finally block will:
-                // A) do nothing
-                // B) eat marks created in the stream previously
+                // We need to set mark again, to make sure the reset call in
+                // the finally block will not consume existing marks
                 stream.mark();
 
                 skipNullHeader(stream);
@@ -118,7 +117,7 @@ public final class PICTImageReaderSpi extends ImageReaderSpiBase {
         return (magic & 0xffff0000) == PICT.MAGIC_V1 || magic == PICT.MAGIC_V2;
     }
 
-    public ImageReader createReaderInstance(final Object pExtension) throws IOException {
+    public ImageReader createReaderInstance(final Object pExtension) {
         return new PICTImageReader(this);
     }
 
diff --git a/imageio/imageio-pict/src/test/java/com/twelvemonkeys/imageio/plugins/pict/PICTImageReaderTest.java b/imageio/imageio-pict/src/test/java/com/twelvemonkeys/imageio/plugins/pict/PICTImageReaderTest.java
index 15078df2..b565d6d8 100644
--- a/imageio/imageio-pict/src/test/java/com/twelvemonkeys/imageio/plugins/pict/PICTImageReaderTest.java
+++ b/imageio/imageio-pict/src/test/java/com/twelvemonkeys/imageio/plugins/pict/PICTImageReaderTest.java
@@ -8,6 +8,7 @@ import org.junit.Test;
 
 import javax.imageio.spi.IIORegistry;
 import javax.imageio.spi.ImageReaderSpi;
+import javax.imageio.stream.ImageInputStream;
 import java.awt.*;
 import java.awt.image.BufferedImage;
 import java.io.IOException;
@@ -15,6 +16,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 
 /**
@@ -91,6 +93,21 @@ public class PICTImageReaderTest extends ImageReaderAbstractTest<PICTImageReader
         super.testReadWithSubsampleParamPixels();
     }
 
+    @Test
+    public void testProviderShouldNotConsumeExistingMarks() throws IOException {
+        try (ImageInputStream stream = new ByteArrayImageInputStream(new byte[1024])) {
+            stream.seek(42);
+            stream.mark();
+            stream.seek(123);
+
+            sProvider.canDecodeInput(stream);
+
+            assertEquals(123, stream.getStreamPosition());
+            stream.reset();
+            assertEquals(42, stream.getStreamPosition());
+        }
+    }
+
     // Regression tests
 
     @Test