Add RPYC2 decompilation code to un.rpyc. Since ren'py maintains backw…

…ards compatibility with the old rpyc format no further changes should be necessary

un.rpyc/unrpyc-compile.py

@@ -46,7 +46,21 @@ def __setstate__(self, state):
 
 def read_ast_from_file(in_file):
     # .rpyc files are just zlib compressed pickles of a tuple of some data and the actual AST of the file
-    raw_contents = in_file.read().decode('zlib')
+    raw_contents = in_file.read()
+    if raw_contents.startswith("RENPY RPC2"):
+        # parse the archive structure
+        position = 10
+        chunks = {}
+        while True:
+            slot, start, length = struct.unpack("III", raw_contents[position: position + 12])
+            if slot == 0:
+                break
+            position += 12
+
+            chunks[slot] = raw_contents[start: start + length]
+
+        raw_contents = chunks[1]
+    raw_contents = raw_contents.decode('zlib')
     data, stmts = magic.safe_loads(raw_contents, factory, ("_ast",))
     return stmts