GCMemcard: Avoid undefined behavior in the static Format().

1 files changed, 9 insertions, 8 deletions

diff --git a/Source/Core/Core/HW/GCMemcard/GCMemcard.cpp b/Source/Core/Core/HW/GCMemcard/GCMemcard.cpp
index 27149e7895..8da2ff856d 100644
--- a/Source/Core/Core/HW/GCMemcard/GCMemcard.cpp
+++ b/Source/Core/Core/HW/GCMemcard/GCMemcard.cpp
@@ -1373,16 +1373,17 @@ bool GCMemcard::Format(u8* card_data, const CardFlashId& flash_id, u16 size_mbit
 {
   if (!card_data)
     return false;
-  memset(card_data, 0xFF, BLOCK_SIZE * 3);
-  memset(card_data + BLOCK_SIZE * 3, 0, BLOCK_SIZE * 2);
 
-  *((Header*)card_data) =
-      Header(flash_id, size_mbits, shift_jis, rtc_bias, sram_language, format_time);
+  Header header(flash_id, size_mbits, shift_jis, rtc_bias, sram_language, format_time);
+  Directory dir;
+  BlockAlloc bat(size_mbits);
+
+  std::memcpy(&card_data[BLOCK_SIZE * 0], &header, BLOCK_SIZE);
+  std::memcpy(&card_data[BLOCK_SIZE * 1], &dir, BLOCK_SIZE);
+  std::memcpy(&card_data[BLOCK_SIZE * 2], &dir, BLOCK_SIZE);
+  std::memcpy(&card_data[BLOCK_SIZE * 3], &bat, BLOCK_SIZE);
+  std::memcpy(&card_data[BLOCK_SIZE * 4], &bat, BLOCK_SIZE);
 
-  *((Directory*)(card_data + BLOCK_SIZE)) = Directory();
-  *((Directory*)(card_data + BLOCK_SIZE * 2)) = Directory();
-  *((BlockAlloc*)(card_data + BLOCK_SIZE * 3)) = BlockAlloc(size_mbits);
-  *((BlockAlloc*)(card_data + BLOCK_SIZE * 4)) = BlockAlloc(size_mbits);
   return true;
 }