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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Netty 4 IndexOutOfBoundsException due to writer index exceeding buffer capacity","articleBody":"Netty 4.1.30 and above (plus earlier versions intermittently) fail the following test:\r\n\r\n```java\r\n[INFO] Running org.lmdbjava.CursorParamTest\r\n[ERROR] Tests run: 5, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.78 s \u003c\u003c\u003c FAILURE! - in org.lmdbjava.CursorParamTest\r\n[ERROR] execute[4: buffer adapter: org.lmdbjava.CursorParamTest$NettyBufferRunner@68b7bdcb](org.lmdbjava.CursorParamTest)  Time elapsed: 0.015 s  \u003c\u003c\u003c ERROR!\r\njava.lang.IndexOutOfBoundsException: readerIndex: 0, writerIndex: 8 (expected: 0 \u003c= readerIndex \u003c= writerIndex \u003c= capacity(4))\r\n\tat io.netty.buffer.AbstractByteBuf.checkIndexBounds(AbstractByteBuf.java:112)\r\n\tat io.netty.buffer.AbstractByteBuf.readerIndex(AbstractByteBuf.java:121)\r\n\tat org.lmdbjava.ByteBufProxy.out(ByteBufProxy.java:144)\r\n\tat org.lmdbjava.ByteBufProxy.out(ByteBufProxy.java:39)\r\n\tat org.lmdbjava.KeyVal.valOut(KeyVal.java:133)\r\n\tat org.lmdbjava.Cursor.get(Cursor.java:153)\r\n\tat org.lmdbjava.CursorParamTest$AbstractBufferRunner.execute(CursorParamTest.java:127)\r\n\tat org.lmdbjava.CursorParamTest.execute(CursorParamTest.java:90)\r\n```\r\n\r\nTwo issues were identified in `ButeBufProxy`:\r\n\r\n1. The unsafe setting of the `LENGTH_OFFSET` was setting the value as a `long`, whereas the actual field in the Java `PooledByteBuf` type is an `int`. \r\n2. The order of updating the `readerIndex` before the `writerIndex` was causing the bounds check on the `readerIndex` call to fail as the `writerIndex` had not yet been corrected.\r\n\r\nCorrection of the above causes tests to pass consistently with Netty 4.1.32 (currently the latest version).\r\n\r\ncc #90 #96 #111 ","author":{"url":"https://github.com/bp-alex","@type":"Person","name":"bp-alex"},"datePublished":"2018-12-18T00:42:36.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/113/lmdbjava/issues/113"}