1 files changed, 22 insertions, 27 deletions

diff --git a/src/3rdparty/angle/src/libGLESv2/renderer/IndexBuffer.cpp b/src/3rdparty/angle/src/libGLESv2/renderer/IndexBuffer.cpp
index 16fd782315..37dbd3e195 100644
--- a/src/3rdparty/angle/src/libGLESv2/renderer/IndexBuffer.cpp
+++ b/src/3rdparty/angle/src/libGLESv2/renderer/IndexBuffer.cpp
@@ -67,18 +67,30 @@ unsigned int IndexBufferInterface::getSerial() const
     return mIndexBuffer->getSerial();
 }
 
-int IndexBufferInterface::mapBuffer(unsigned int size, void** outMappedMemory)
+bool IndexBufferInterface::mapBuffer(unsigned int size, void** outMappedMemory, unsigned int *streamOffset)
 {
+    // Protect against integer overflow
+    if (mWritePosition + size < mWritePosition)
+    {
+        return false;
+    }
+
     if (!mIndexBuffer->mapBuffer(mWritePosition, size, outMappedMemory))
     {
-        *outMappedMemory = NULL;
-        return -1;
+        if (outMappedMemory)
+        {
+            *outMappedMemory = NULL;
+        }
+        return false;
     }
 
-    int oldWritePos = static_cast<int>(mWritePosition);
-    mWritePosition += size;
+    if (streamOffset)
+    {
+        *streamOffset = mWritePosition;
+    }
 
-    return oldWritePos;
+    mWritePosition += size;
+    return true;
 }
 
 bool IndexBufferInterface::unmapBuffer()
@@ -130,12 +142,13 @@ bool StreamingIndexBufferInterface::reserveBufferSpace(unsigned int size, GLenum
 {
     bool result = true;
     unsigned int curBufferSize = getBufferSize();
+    unsigned int writePos = getWritePosition();
     if (size > curBufferSize)
     {
         result = setBufferSize(std::max(size, 2 * curBufferSize), indexType);
         setWritePosition(0);
     }
-    else if (getWritePosition() + size > curBufferSize)
+    else if (writePos + size > curBufferSize || writePos + size < writePos)
     {
         if (!discard())
         {
@@ -175,27 +188,9 @@ bool StaticIndexBufferInterface::reserveBufferSpace(unsigned int size, GLenum in
     }
 }
 
-unsigned int StaticIndexBufferInterface::lookupRange(intptr_t offset, GLsizei count, unsigned int *minIndex, unsigned int *maxIndex)
-{
-    IndexRange range = {offset, count};
-
-    std::map<IndexRange, IndexResult>::iterator res = mCache.find(range);
-
-    if (res == mCache.end())
-    {
-        return -1;
-    }
-
-    *minIndex = res->second.minIndex;
-    *maxIndex = res->second.maxIndex;
-    return res->second.streamOffset;
-}
-
-void StaticIndexBufferInterface::addRange(intptr_t offset, GLsizei count, unsigned int minIndex, unsigned int maxIndex, unsigned int streamOffset)
+IndexRangeCache *StaticIndexBufferInterface::getIndexRangeCache()
 {
-    IndexRange indexRange = {offset, count};
-    IndexResult indexResult = {minIndex, maxIndex, streamOffset};
-    mCache[indexRange] = indexResult;
+    return &mIndexRangeCache;
 }
 
 }