Bug #330645 - Make _unregister_module_proxy() detect partially imported

modules (indicated when an AttributeError is caught) and handle them
appropriately.

diff --git a/pym/portage/proxy/lazyimport.py b/pym/portage/proxy/lazyimport.py
index 56591c03742dacc95685cfc7a374c8440b1a3702..c9147caead57286d5379cfbd31cec06e7eb87412 100644 (file)
--- a/pym/portage/proxy/lazyimport.py
+++ b/pym/portage/proxy/lazyimport.py
@@ -53,19 +53,13 @@ def _unregister_module_proxy(name):
        Destroy all proxies that reference the give module name. Also, check
        for other proxies referenced by modules that have been imported and
        destroy those proxies too. This way, destruction of a single proxy
-       can trigger destruction of all the rest.
+       can trigger destruction of all the rest. If the a target module appears
+       to be partially imported (indicated when an AttributeError is caught),
+       this function will leave in place proxies that reference it.
        """
        _module_proxies_lock.acquire()
        try:
-               proxy_list = _module_proxies.get(name)
-               if proxy_list is not None:
-                       # First delete this name from the dict so that
-                       # if this same thread reenters below, it won't
-                       # enter this path again.
-                       del _module_proxies[name]
-                       for proxy in proxy_list:
-                               object.__getattribute__(proxy, '_get_target')()
-
+               if name in _module_proxies:
                        modules = sys.modules
                        for name, proxy_list in list(_module_proxies.items()):
                                if name not in modules:
@@ -74,8 +68,16 @@ def _unregister_module_proxy(name):
                                # if this same thread reenters below, it won't
                                # enter this path again.
                                del _module_proxies[name]
-                               for proxy in proxy_list:
-                                       object.__getattribute__(proxy, '_get_target')()
+                               try:
+                                       while proxy_list:
+                                               proxy = proxy_list.pop()
+                                               object.__getattribute__(proxy, '_get_target')()
+                               except AttributeError:
+                                       # Apparently the target module is only partially
+                                       # imported, so proxies that reference it cannot
+                                       # be destroyed yet.
+                                       proxy_list.append(proxy)
+                                       _module_proxies[name] = proxy_list
        finally:
                _module_proxies_lock.release()
 
@@ -120,6 +122,9 @@ class _LazyImportFrom(_LazyImport):
                name = object.__getattribute__(self, '_name')
                attr_name = object.__getattribute__(self, '_attr_name')
                __import__(name)
+               # If called by _unregister_module_proxy() and the target module is
+               # partially imported, then the following getattr call may raise an
+               # AttributeError for _unregister_module_proxy() to handle.
                target = getattr(sys.modules[name], attr_name)
                object.__setattr__(self, '_target', target)
                object.__getattribute__(self, '_scope')[