When writing a negative sign the write(char) method goes directly to the output stream and by-passes the internal RedisOutputStream buffer causing random corruption of the output. Casting the char to a byte ensures write(byte) is called which will properly buffer the output.

src/main/java/redis/clients/util/RedisOutputStream.java

@@ -187,7 +187,7 @@ public final class RedisOutputStream extends FilterOutputStream {
 
     public void writeIntCrLf(int value) throws IOException {
         if (value < 0) {
-            write('-');
+            write((byte)'-');
             value = -value;
         }