Fix in VmaBlockMetadata_Linear::CreateAllocationRequest for too large allocations

Fixes #396 - thanks @dm-tesla

Author: adam-sawicki-a

include/vk_mem_alloc.h

@@ -7808,6 +7808,10 @@ bool VmaBlockMetadata_Linear::CreateAllocationRequest(
     VMA_ASSERT(allocType != VMA_SUBALLOCATION_TYPE_FREE);
     VMA_ASSERT(pAllocationRequest != VMA_NULL);
     VMA_HEAVY_ASSERT(Validate());
+
+    if(allocSize > GetSize())
+        return false;
+
     pAllocationRequest->size = allocSize;
     return upperAddress ?
         CreateAllocationRequest_UpperAddress(

src/Tests.cpp

@@ -3425,6 +3425,14 @@ static void TestVirtualBlocksAlgorithms()
         };
         std::vector<AllocData> allocations;
 
+        // Test too large allocation
+        {
+            VmaVirtualAllocationCreateInfo allocCreateInfo = {};
+            allocCreateInfo.size = blockCreateInfo.size * 2;
+            VmaVirtualAllocation alloc;
+            TEST(vmaVirtualAllocate(block, &allocCreateInfo, &alloc, nullptr) < 0);
+        }
+
         // Make some allocations
         for(size_t i = 0; i < 20; ++i)
         {