commit eb45c2a1e48cc50f70298a34702fb365c61b489d
author zeshuai007 <51382517@qq.com> Mon Jul 06 16:53:47 2020 +0800
committer Jens Geyer <jensg@apache.org> Tue Jul 07 22:18:07 2020 +0200
tree 53fcab0c8ebbdafe72ee483ea37ecd92ba288649
parent dd0918713d8b5db0a2cf9c3bd7141c2e252bd7e4

THRIFT-5247 Avoiding meaningless System.copy
Client: java
Patch: Zezeng Wang

This closes #2196

lib/java/src/org/apache/thrift/transport/AutoExpandingBufferReadTransport.java

diff --git a/lib/java/src/org/apache/thrift/transport/AutoExpandingBufferReadTransport.java b/lib/java/src/org/apache/thrift/transport/AutoExpandingBufferReadTransport.java
index a28d254..d06fec7 100644
--- a/lib/java/src/org/apache/thrift/transport/AutoExpandingBufferReadTransport.java
+++ b/lib/java/src/org/apache/thrift/transport/AutoExpandingBufferReadTransport.java
@@ -51,8 +51,10 @@
   @Override
   public final int read(byte[] target, int off, int len) throws TTransportException {
     int amtToRead = Math.min(len, getBytesRemainingInBuffer());
-    System.arraycopy(buf.array(), pos, target, off, amtToRead);
-    consumeBuffer(amtToRead);
+    if(amtToRead > 0){
+      System.arraycopy(buf.array(), pos, target, off, amtToRead);
+      consumeBuffer(amtToRead);
+    }
     return amtToRead;
   }
 
@@ -81,4 +83,3 @@
     return limit - pos;
   }
 }
-  
\ No newline at end of file