HandleAllocator: make HandleRange inclusive.

src/libANGLE/HandleAllocator.cpp

@@ -63,11 +63,14 @@ GLuint HandleAllocator::allocate()
     GLuint freeListHandle = listIt->begin;
     ASSERT(freeListHandle > 0);
 
-    listIt->begin++;
     if (listIt->begin == listIt->end)
     {
         mUnallocatedList.erase(listIt);
     }
+    else
+    {
+        listIt->begin++;
+    }
 
     return freeListHandle;
 }
@@ -101,7 +104,7 @@ void HandleAllocator::reserve(GLuint handle)
 
     if (handle == begin || handle == end)
     {
-        if (begin + 1 == end)
+        if (begin == end)
         {
             mUnallocatedList.erase(boundIt);
         }
@@ -117,18 +120,12 @@ void HandleAllocator::reserve(GLuint handle)
         return;
     }
 
+    ASSERT(begin < handle && handle < end);
+
     // need to split the range
     auto placementIt = mUnallocatedList.erase(boundIt);
-
-    if (handle + 1 != end)
-    {
-        placementIt = mUnallocatedList.insert(placementIt, HandleRange(handle + 1, end));
-    }
-    if (begin != handle)
-    {
-        ASSERT(begin < handle);
-        mUnallocatedList.insert(placementIt, HandleRange(begin, handle));
-    }
+    placementIt      = mUnallocatedList.insert(placementIt, HandleRange(handle + 1, end));
+    mUnallocatedList.insert(placementIt, HandleRange(begin, handle - 1));
 }
 
 }  // namespace gl

src/libANGLE/HandleAllocator.h

@@ -41,6 +41,7 @@ class HandleAllocator final : angle::NonCopyable
     typedef std::vector<GLuint> HandleList;
     HandleList mFreeValues;
 
+    // Represents an inclusive range [begin, end]
     struct HandleRange
     {
         HandleRange(GLuint beginIn, GLuint endIn) : begin(beginIn), end(endIn) {}

src/libANGLE/HandleAllocator_unittest.cpp

@@ -90,8 +90,7 @@ TEST(HandleAllocatorTest, Reallocation)
     EXPECT_EQ(finalResult, 1);
 }
 
-// The following test covers reserving a handle with max uint value.
-// See http://anglebug.com/1052
+// The following test covers reserving a handle with max uint value. See http://anglebug.com/1052
 TEST(HandleAllocatorTest, ReserveMaxUintHandle)
 {
     gl::HandleAllocator allocator;
@@ -103,6 +102,19 @@ TEST(HandleAllocatorTest, ReserveMaxUintHandle)
     EXPECT_EQ(1u, normalHandle);
 }
 
+// The following test covers reserving a handle with max uint value minus one then max uint value.
+TEST(HandleAllocatorTest, ReserveMaxUintHandle2)
+{
+    gl::HandleAllocator allocator;
+
+    GLuint maxUintHandle = std::numeric_limits<GLuint>::max();
+    allocator.reserve(maxUintHandle - 1);
+    allocator.reserve(maxUintHandle);
+
+    GLuint normalHandle = allocator.allocate();
+    EXPECT_EQ(1u, normalHandle);
+}
+
 // To test if the allocator keep the handle in a sorted order.
 TEST(HandleAllocatorTest, SortedOrderHandle)
 {