From 1e6351cf759d0b0176c7256d62fb62b2c3e53535 Mon Sep 17 00:00:00 2001
From: Jonathan Trowbridge <jonathan.trowbridge@gmail.com>
Date: Tue, 31 Jul 2018 19:43:07 -0400
Subject: [PATCH] master - fixed off-by-one in buffer state tail index.

---
 .../models/TorrentSessionBufferState.kt                |  2 +-
 .../TorrentSessionBufferStateTest.kt                   | 10 ++++++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/simpletorrentandroid/src/main/java/com/masterwok/simpletorrentandroid/models/TorrentSessionBufferState.kt b/simpletorrentandroid/src/main/java/com/masterwok/simpletorrentandroid/models/TorrentSessionBufferState.kt
index 12e8adb..d156815 100644
--- a/simpletorrentandroid/src/main/java/com/masterwok/simpletorrentandroid/models/TorrentSessionBufferState.kt
+++ b/simpletorrentandroid/src/main/java/com/masterwok/simpletorrentandroid/models/TorrentSessionBufferState.kt
@@ -24,7 +24,7 @@ class TorrentSessionBufferState constructor(
             field = value
         }
 
-    var bufferTailIndex = startIndex + bufferSize
+    var bufferTailIndex = startIndex + bufferSize - 1
         @Synchronized
         get() = field
         private set(value) {
diff --git a/simpletorrentandroid/src/test/java/com/masterwok/simpletorrentandroid/TorrentSessionBufferStateTest.kt b/simpletorrentandroid/src/test/java/com/masterwok/simpletorrentandroid/TorrentSessionBufferStateTest.kt
index 8663ef6..8f8e99f 100644
--- a/simpletorrentandroid/src/test/java/com/masterwok/simpletorrentandroid/TorrentSessionBufferStateTest.kt
+++ b/simpletorrentandroid/src/test/java/com/masterwok/simpletorrentandroid/TorrentSessionBufferStateTest.kt
@@ -22,7 +22,7 @@ class TorrentSessionBufferStateTest {
             bufferHeadIndex: Int
             , endIndex: Int
             , bufferSize: Int
-    ): Int = Math.min(bufferHeadIndex + bufferSize, endIndex)
+    ): Int = Math.min(bufferHeadIndex + bufferSize - 1, endIndex)
 
     private fun IntRange.random(): Int {
         return Random().nextInt((endInclusive + 1) - start) + start
@@ -185,8 +185,14 @@ class TorrentSessionBufferStateTest {
 
         underTest.setPieceDownloaded(0)
 
+        val expectedTail = getExpectedTailIndex(
+                underTest.bufferHeadIndex
+                , underTest.endIndex
+                , bufferSize
+        )
+
         assertEquals(underTest.bufferHeadIndex, 30)
-        assertEquals(underTest.bufferTailIndex, Math.min(underTest.bufferHeadIndex + bufferSize, endIndex))
+        assertEquals(underTest.bufferTailIndex, Math.min(expectedTail, endIndex))
     }
 
     @Test