Fix lua wrapper sizeof for static arrays.

Since it actually depends on the element type, it is more tricky.

library/DataDefs.cpp

@@ -42,13 +42,14 @@ using namespace DFHack;
 
 
 void *type_identity::do_allocate_pod() {
-    void *p = malloc(size);
-    memset(p, 0, size);
+    size_t sz = byte_size();
+    void *p = malloc(sz);
+    memset(p, 0, sz);
     return p;
 }
 
 void type_identity::do_copy_pod(void *tgt, const void *src) {
-    memmove(tgt, src, size);
+    memmove(tgt, src, byte_size());
 };
 
 bool type_identity::do_destroy_pod(void *obj) {
@@ -81,8 +82,9 @@ bool type_identity::destroy(void *obj) {
 }
 
 void *enum_identity::do_allocate() {
-    void *p = malloc(byte_size());
-    memcpy(p, &first_item_value, std::min(byte_size(), sizeof(int64_t)));
+    size_t sz = byte_size();
+    void *p = malloc(sz);
+    memcpy(p, &first_item_value, std::min(sz, sizeof(int64_t)));
     return p;
 }
 

library/LuaWrapper.cpp

@@ -542,10 +542,23 @@ static int meta_sizeof(lua_State *state)
         return 2;
     }
 
-    type_identity *id = get_object_identity(state, 1, "df.sizeof()", true);
+    type_identity *id = get_object_identity(state, 1, "df.sizeof()", true, true);
 
-    lua_pushinteger(state, id->byte_size());
+    // Static arrays need special handling
+    if (id->type() == IDTYPE_BUFFER)
+    {
+        auto buf = (df::buffer_container_identity*)id;
+        type_identity *item = buf->getItemType();
+        int count = buf->getSize();
+
+        fetch_container_details(state, lua_gettop(state), &item, &count);
+
+        lua_pushinteger(state, item->byte_size() * count);
+    }
+    else
+        lua_pushinteger(state, id->byte_size());
 
+    // Add the address
     if (lua_isuserdata(state, 1))
     {
         lua_pushnumber(state, (size_t)get_object_ref(state, 1));

library/include/DataDefs.h

@@ -83,7 +83,7 @@ namespace DFHack
     public:
         virtual ~type_identity() {}
 
-        size_t byte_size() { return size; }
+        virtual size_t byte_size() { return size; }
 
         virtual identity_type type() = 0;
 

library/include/DataIdentity.h

@@ -289,9 +289,11 @@ namespace df
         {}
 
         buffer_container_identity(int size, type_identity *item, enum_identity *ienum = NULL)
-            : container_identity(item->byte_size()*size, NULL, item, ienum), size(size)
+            : container_identity(0, NULL, item, ienum), size(size)
         {}
 
+        size_t byte_size() { return getItemType()->byte_size()*size; }
+
         std::string getFullName(type_identity *item);
         int getSize() { return size; }