# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1481059629 -3600
# Node ID c3aadc0a672daed52bc82db7fe381983462a4fec
# Parent  aa10eecbc8ce350f4ad5057b2689bd04277b00f1
Attempt to handle module ordering dependencies caused by function defaults.

diff -r aa10eecbc8ce -r c3aadc0a672d importer.py
--- a/importer.py	Tue Dec 06 21:26:58 2016 +0100
+++ b/importer.py	Tue Dec 06 22:27:09 2016 +0100
@@ -445,7 +445,7 @@
 
                         # Record a module ordering dependency.
 
-                        if not found.static():
+                        if not found.static() or self.uses_dynamic_callable(found):
                             init_item(self.depends, module.name, set)
                             self.depends[module.name].add(provider)
 
@@ -470,6 +470,16 @@
                         print >>sys.stderr, "Requiring", provider
                     self.require_providers(provider)
 
+    def uses_dynamic_callable(self, ref):
+
+        """
+        Return whether 'ref' refers to a callable employing defaults that may
+        need initialising before the callable can be used.
+        """
+
+        return ref.has_kind("<function>") and self.function_defaults.get(ref.get_origin()) or \
+               ref.has_kind("<class>") and self.function_defaults.get("%s.__init__" % ref.get_origin())
+
     def order_modules(self):
 
         "Produce a module initialisation ordering."