[netty#1976] Fix IndexOutOfBoundsException when calling CompositeByte…

…Buf.discardReadComponents()
bxvs888 · Nov 9, 2013 · b00f8c6 · b00f8c6
1 parent e4f391f
commit b00f8c6
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Showing 2 changed files with 21 additions and 2 deletions.
diff --git a/buffer/src/main/java/io/netty/buffer/CompositeByteBuf.java b/buffer/src/main/java/io/netty/buffer/CompositeByteBuf.java
@@ -1257,9 +1257,10 @@ public CompositeByteBuf discardReadComponents() {
 
         // Update indexes and markers.
         Component first = components.get(0);
+        int offset = first.offset;
         updateComponentOffsets(0);
-        setIndex(readerIndex - first.offset, writerIndex - first.offset);
-        adjustMarkers(first.offset);
+        setIndex(readerIndex - offset, writerIndex - offset);
+        adjustMarkers(offset);
         return this;
     }
 

diff --git a/buffer/src/test/java/io/netty/buffer/AbstractCompositeByteBufTest.java b/buffer/src/test/java/io/netty/buffer/AbstractCompositeByteBufTest.java
@@ -790,4 +790,22 @@ public void testisDirectMultipleBufs() {
         buf.addComponent(buffer().writeByte(1));
         assertFalse(buf.isDirect());
     }
+
+    // See https://github.com/netty/netty/issues/1976
+    @Test
+    public void testDiscardSomeReadBytes() {
+        CompositeByteBuf cbuf = freeLater(compositeBuffer());
+        int len = 8 * 4;
+        for (int i = 0; i < len; i += 4) {
+            ByteBuf buf = Unpooled.buffer().writeInt(i);
+            cbuf.capacity(cbuf.writerIndex()).addComponent(buf).writerIndex(i + 4);
+        }
+        cbuf.writeByte(1);
+
+        byte[] me = new byte[len];
+        cbuf.readBytes(me);
+        cbuf.readByte();
+
+        cbuf.discardSomeReadBytes();
+    }
 }