dist: Work around stdlib bug causing erroneous missing module warnings

direct/src/dist/FreezeTool.py

@@ -2428,6 +2428,76 @@ class PandaModuleFinder(modulefinder.ModuleFinder):
                         self.msg(2, "ImportError:", str(msg))
                         self._add_badmodule(fullname, caller)
 
+    def scan_code(self, co, m):
+        code = co.co_code
+        # This was renamed to scan_opcodes in Python 3.6
+        if hasattr(self, 'scan_opcodes_25'):
+            scanner = self.scan_opcodes_25
+        else:
+            scanner = self.scan_opcodes
+
+        for what, args in scanner(co):
+            if what == "store":
+                name, = args
+                m.globalnames[name] = 1
+            elif what in ("import", "absolute_import"):
+                fromlist, name = args
+                have_star = 0
+                if fromlist is not None:
+                    if "*" in fromlist:
+                        have_star = 1
+                    fromlist = [f for f in fromlist if f != "*"]
+                if what == "absolute_import": level = 0
+                else: level = -1
+                self._safe_import_hook(name, m, fromlist, level=level)
+                if have_star:
+                    # We've encountered an "import *". If it is a Python module,
+                    # the code has already been parsed and we can suck out the
+                    # global names.
+                    mm = None
+                    if m.__path__:
+                        # At this point we don't know whether 'name' is a
+                        # submodule of 'm' or a global module. Let's just try
+                        # the full name first.
+                        mm = self.modules.get(m.__name__ + "." + name)
+                    if mm is None:
+                        mm = self.modules.get(name)
+                    if mm is not None:
+                        m.globalnames.update(mm.globalnames)
+                        m.starimports.update(mm.starimports)
+                        if mm.__code__ is None:
+                            m.starimports[name] = 1
+                    else:
+                        m.starimports[name] = 1
+            elif what == "relative_import":
+                level, fromlist, name = args
+                parent = self.determine_parent(m, level=level)
+                if name:
+                    self._safe_import_hook(name, m, fromlist, level=level)
+                else:
+                    self._safe_import_hook(parent.__name__, None, fromlist, level=0)
+
+                if fromlist and "*" in fromlist:
+                    if name:
+                        mm = self.modules.get(parent.__name__ + "." + name)
+                    else:
+                        mm = self.modules.get(parent.__name__)
+
+                    if mm is not None:
+                        m.globalnames.update(mm.globalnames)
+                        m.starimports.update(mm.starimports)
+                        if mm.__code__ is None:
+                            m.starimports[name] = 1
+                    else:
+                        m.starimports[name] = 1
+            else:
+                # We don't expect anything else from the generator.
+                raise RuntimeError(what)
+
+        for c in co.co_consts:
+            if isinstance(c, type(co)):
+                self.scan_code(c, m)
+
     def find_module(self, name, path=None, parent=None):
         """ Finds a module with the indicated name on the given search path
         (or self.path if None).  Returns a tuple like (fp, path, stuff), where