From da5264c5422422d021a7e8ff5c6096dc930b117b Mon Sep 17 00:00:00 2001
From: nathan <nathan@dorkbox.com>
Date: Tue, 18 Aug 2020 01:49:19 +0200
Subject: [PATCH] Fixed RMI short/int packing for negative numbers

---
 src/dorkbox/network/rmi/RmiUtils.kt           |  9 ++---
 test/dorkboxTest/network/rmi/RmiPackIdTest.kt | 40 +++++++++++++++++++
 2 files changed, 44 insertions(+), 5 deletions(-)
 create mode 100644 test/dorkboxTest/network/rmi/RmiPackIdTest.kt

diff --git a/src/dorkbox/network/rmi/RmiUtils.kt b/src/dorkbox/network/rmi/RmiUtils.kt
index c46b8f9a..2bae4849 100644
--- a/src/dorkbox/network/rmi/RmiUtils.kt
+++ b/src/dorkbox/network/rmi/RmiUtils.kt
@@ -427,16 +427,15 @@ object RmiUtils {
         return allClasses
     }
 
-    private const val RIGHT = 0xFFFF
     fun packShorts(left: Int, right: Int): Int {
-        return left shl 16 or (right and RIGHT)
+        return left shl 16 or (right and 0xFFFF)
     }
 
     fun unpackLeft(packedInt: Int): Int {
-        return packedInt ushr 16 // >>> operator 0-fills from left
-
+        return packedInt shr 16
     }
+
     fun unpackRight(packedInt: Int): Int {
-        return packedInt and RIGHT
+        return packedInt.toShort().toInt()
     }
 }
diff --git a/test/dorkboxTest/network/rmi/RmiPackIdTest.kt b/test/dorkboxTest/network/rmi/RmiPackIdTest.kt
new file mode 100644
index 00000000..29bd87c0
--- /dev/null
+++ b/test/dorkboxTest/network/rmi/RmiPackIdTest.kt
@@ -0,0 +1,40 @@
+package dorkboxTest.network.rmi
+
+import dorkbox.network.rmi.RmiUtils
+import org.junit.Assert
+import org.junit.Test
+
+/**
+ *
+ */
+class RmiPackIdTest {
+    @Test
+    fun rmiObjectIdNegative() {
+        // these are SHORTS, so SHORT.MIN -> SHORT.MAX, excluding 0
+        for (rmiObjectId in Short.MIN_VALUE..-1) {
+            for (rmiId in 1..Short.MAX_VALUE) {
+                val packed = RmiUtils.packShorts(rmiObjectId, rmiId)
+                val rmiObjectId2 = RmiUtils.unpackLeft(packed)
+                val rmiId2 = RmiUtils.unpackRight(packed)
+
+                Assert.assertEquals(rmiObjectId, rmiObjectId2)
+                Assert.assertEquals(rmiId, rmiId2)
+            }
+        }
+    }
+
+    @Test
+    fun rmiIdNegative() {
+        // these are SHORTS, so SHORT.MIN -> SHORT.MAX, excluding 0
+        for (rmiId in Short.MIN_VALUE..-1) {
+            for (rmiObjectId in 1..Short.MAX_VALUE) {
+                val packed = RmiUtils.packShorts(rmiObjectId, rmiId)
+                val rmiObjectId2 = RmiUtils.unpackLeft(packed)
+                val rmiId2 = RmiUtils.unpackRight(packed)
+
+                Assert.assertEquals(rmiObjectId, rmiObjectId2)
+                Assert.assertEquals(rmiId, rmiId2)
+            }
+        }
+    }
+}