From 0d1c8b8d315bb4e603fcac9ea8920cce759f7993 Mon Sep 17 00:00:00 2001
From: Matt <m.moninger.h@gmail.com>
Date: Mon, 4 Feb 2019 14:50:14 +0100
Subject: [PATCH] Fix CircularBuffer push_back method.

---
 src/openrct2/core/CircularBuffer.h | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/src/openrct2/core/CircularBuffer.h b/src/openrct2/core/CircularBuffer.h
index ff18ad7eae..e897a69fae 100644
--- a/src/openrct2/core/CircularBuffer.h
+++ b/src/openrct2/core/CircularBuffer.h
@@ -78,16 +78,30 @@ public:
 
     void push_back(const value_type& val)
     {
-        if (_size == capacity())
+        if (_size == 0)
         {
-            _head = (_head + 1) % capacity();
+            _elements[_head] = val;
+            _tail = _head;
+            _size++;
+        }
+        else if (_size != capacity())
+        {
+            _tail++;
+            if (_tail == capacity())
+                _tail = 0;
+            _size++;
+            _elements[_tail] = val;
         }
         else
         {
-            _size++;
+            _head++;
+            if (_head == capacity())
+                _head = 0;
+            _tail++;
+            if (_tail == capacity())
+                _tail = 0;
+            _elements[_tail] = val;
         }
-        _elements[_tail] = val;
-        _tail = (_tail + 1) % capacity();
     }
 
 private: