[PATCH] java.nio/6593946 ByteBuffer.compact does not clear mark

[Keith Seitz]

Hi,

The attached patch should fix the mark problem with ByteBuffer.compact, 
which simply was not following the API specification.

I'm also attaching a simple jtreg testcase for this.

Keith
diff -r 317d604b4da9 j2se/src/share/classes/java/nio/Buffer.java
--- a/j2se/src/share/classes/java/nio/Buffer.java	Tue Sep 25 12:45:52 2007 -0700
+++ b/j2se/src/share/classes/java/nio/Buffer.java	Tue Sep 25 12:47:10 2007 -0700
@@ -235,7 +235,7 @@ public abstract class Buffer {
 	if ((newPosition > limit) || (newPosition < 0))
 	    throw new IllegalArgumentException();
 	position = newPosition;
-	if (mark > position) mark = -1;
+	if (mark > position) clearMark();
 	return this;
     }
 
@@ -267,7 +267,7 @@ public abstract class Buffer {
 	    throw new IllegalArgumentException();
 	limit = newLimit;
 	if (position > limit) position = limit;
-	if (mark > limit) mark = -1;
+	if (mark > limit) clearMark();
 	return this;
     }
 
@@ -320,7 +320,7 @@ public abstract class Buffer {
     public final Buffer clear() {
 	position = 0;
 	limit = capacity;
-	mark = -1;
+	clearMark();
 	return this;
     }
 
@@ -348,7 +348,7 @@ public abstract class Buffer {
     public final Buffer flip() {
 	limit = position;
 	position = 0;
-	mark = -1;
+	clearMark();
 	return this;
     }
 
@@ -369,7 +369,7 @@ public abstract class Buffer {
      */
     public final Buffer rewind() {
 	position = 0;
-	mark = -1;
+	clearMark();
 	return this;
     }
 
@@ -543,6 +543,10 @@ public abstract class Buffer {
 	return mark;
     }
 
+    final void clearMark() {                            // package-private
+        mark = -1;
+    }
+
     static void checkBounds(int off, int len, int size) { // package-private
         if ((off | len | (off + len) | (size - (off + len))) < 0)
 	    throw new IndexOutOfBoundsException();
diff -r 317d604b4da9 j2se/src/share/classes/java/nio/Direct-X-Buffer.java
--- a/j2se/src/share/classes/java/nio/Direct-X-Buffer.java	Tue Sep 25 12:45:52 2007 -0700
+++ b/j2se/src/share/classes/java/nio/Direct-X-Buffer.java	Tue Sep 25 12:47:10 2007 -0700
@@ -354,6 +354,7 @@ class Direct$Type$Buffer$RW$$BO$
  	unsafe.copyMemory(ix(pos), ix(0), rem << $LG_BYTES_PER_VALUE$);
  	position(rem);
 	limit(capacity());
+	clearMark();
 	return this;
 #else[rw]
 	throw new ReadOnlyBufferException();
diff -r 317d604b4da9 j2se/src/share/classes/java/nio/Heap-X-Buffer.java
--- a/j2se/src/share/classes/java/nio/Heap-X-Buffer.java	Tue Sep 25 12:45:52 2007 -0700
+++ b/j2se/src/share/classes/java/nio/Heap-X-Buffer.java	Tue Sep 25 12:47:10 2007 -0700
@@ -222,6 +222,7 @@ class Heap$Type$Buffer$RW$
 	System.arraycopy(hb, ix(position()), hb, ix(0), remaining());
 	position(remaining());
 	limit(capacity());
+	clearMark();
 	return this;
 #else[rw]
 	throw new ReadOnlyBufferException();
import java.nio.ByteBuffer;
import java.nio.InvalidMarkException;

/**
 * @test
 * @bug 6593946
 * @summary ByteBuffer.compact should clear mark
 */
public class ByteBufferCompactMark {

  /*
   * Adapted from the mauve test
   */
  public static void main(String[] args) throws Exception {

    ByteBuffer buf = ByteBuffer.allocate(10);
    buf.rewind();
	
    // Fill buffer
    for (int i = 0; i < 10; i++)
      buf.put((byte)(i + 1));

    buf.position(1);
    buf.mark();

    // This should clear/invalidate the mark
    buf.compact();

    try {
      // This should throw an InvalidMarkxception
      buf.reset();
      throw new Exception ("InvalidMarkException not thrown");
    } catch(InvalidMarkException ime) {
      System.out.println("caught expected InvalidMarkException");
    }
  }
}