XPath: Increase memory block alignment to 8 bytes

To be more precise, the memory block is now aligned to be able to reliably
allocate objects with both double and pointer fields. If there is a platform
with a 4-byte double and a 4-byte pointer, the memory block alignment there will
stay the same after this change.

Fixes #48.

1 files changed, 6 insertions, 2 deletions

diff --git a/src/pugixml.cpp b/src/pugixml.cpp
index 5f8dbdb..b3195f7 100644
--- a/src/pugixml.cpp
+++ b/src/pugixml.cpp
@@ -7267,14 +7267,18 @@ PUGI__NS_BEGIN
 	#endif
 		;
 
-	static const uintptr_t xpath_memory_block_alignment = sizeof(void*);
+	static const uintptr_t xpath_memory_block_alignment = sizeof(double) > sizeof(void*) ? sizeof(double) : sizeof(void*);
 
 	struct xpath_memory_block
 	{	
 		xpath_memory_block* next;
 		size_t capacity;
 
-		char data[xpath_memory_page_size];
+		union
+		{
+			char data[xpath_memory_page_size];
+			double alignment;
+		};
 	};
 		
 	class xpath_allocator