Merge pull request #305 from pah/fix/strict-memcpy

Avoid calling memcpy with NULL pointers

include/rapidjson/allocators.h

@@ -160,6 +160,9 @@ class MemoryPoolAllocator {
 
  //! Allocates a memory block. (concept Allocator)
  void* Malloc(size_t size) {
+ if (!size)
+ return NULL;
+
  size = RAPIDJSON_ALIGN(size);
  if (chunkHead_ == 0 || chunkHead_->size + size > chunkHead_->capacity)
  AddChunk(chunk_capacity_ > size ? chunk_capacity_ : size);
@@ -191,7 +194,9 @@ class MemoryPoolAllocator {
  // Realloc process: allocate and copy memory, do not free original buffer.
  void* newBuffer = Malloc(newSize);
  RAPIDJSON_ASSERT(newBuffer != 0); // Do not handle out-of-memory explicitly.
- return std::memcpy(newBuffer, originalPtr, originalSize);
+ if (originalSize)
+ std::memcpy(newBuffer, originalPtr, originalSize);
+ return newBuffer;
  }
 
  //! Frees a memory block (concept Allocator)

include/rapidjson/document.h

@@ -1579,16 +1579,24 @@ class GenericValue {
  // Initialize this value as array with initial data, without calling destructor.
  void SetArrayRaw(GenericValue* values, SizeType count, Allocator& allocator) {
  flags_ = kArrayFlag;
- data_.a.elements = (GenericValue*)allocator.Malloc(count * sizeof(GenericValue));
- std::memcpy(data_.a.elements, values, count * sizeof(GenericValue));
+ if (count) {
+ data_.a.elements = (GenericValue*)allocator.Malloc(count * sizeof(GenericValue));
+ std::memcpy(data_.a.elements, values, count * sizeof(GenericValue));
+ }
+ else
+ data_.a.elements = NULL;
  data_.a.size = data_.a.capacity = count;
  }
 
  //! Initialize this value as object with initial data, without calling destructor.
  void SetObjectRaw(Member* members, SizeType count, Allocator& allocator) {
  flags_ = kObjectFlag;
- data_.o.members = (Member*)allocator.Malloc(count * sizeof(Member));
- std::memcpy(data_.o.members, members, count * sizeof(Member));
+ if (count) {
+ data_.o.members = (Member*)allocator.Malloc(count * sizeof(Member));
+ std::memcpy(data_.o.members, members, count * sizeof(Member));
+ }
+ else
+ data_.o.members = NULL;
  data_.o.size = data_.o.capacity = count;
  }