More robust for Graal

Author: rocky

xdis/bytecode_graal.py

@@ -117,7 +117,11 @@ def get_instructions_bytes_graal(
                 if arg >= len(cells):
                     argrepr = freevars[arg - len(cells)]
                 else:
-                    argrepr = cells[arg]
+                    if 0 < arg < len(cells[arg]):
+                        argrepr = cells[arg]
+                    else:
+                        argrepr = "???"
+
                 break
             elif opcode in (
                 opc.opmap["LOAD_FAST"],
@@ -129,7 +133,10 @@ def get_instructions_bytes_graal(
 
             elif optype == "name":
                 argval = arg
-                argrepr = names[arg]
+                if 0 <= arg < len(names):
+                    argrepr = names[arg]
+                else:
+                    argrepr = "??"
                 break
             elif opcode == opc.opmap["FORMAT_VALUE"]:
                 argval = arg

xdis/marsh.py

@@ -650,7 +650,7 @@ def load(self):
         try:
             return self.dispatch[c](self)
         except KeyError:
-            raise ValueError("bad marshal code: %c (%d)" % (c, c))
+            raise ValueError("bad marshal code: %s (%s)" % (hex(c), hex(c)))
 
     def r_byte(self):
         return self._read(1)

xdis/unmarshal.py

@@ -794,6 +794,8 @@ def t_code_old(self, _, bytes_for_s: bool = False):
     # Since Python 3.4
     def t_object_reference(self, save_ref=None, bytes_for_s: bool = False):
         refnum = self.read_uint32()
+        if not (0 < refnum < len(self.intern_objects)):
+            return self.intern_objects[-1]
         return self.intern_objects[refnum]
 
     def t_unknown(self, save_ref=None, bytes_for_s: bool = False):