[pygobject] Proper handling of null-ok in virtual methods

[Tomeu Vizoso <tomeuv src gnome org>]

commit 79acac7b86ec52cd3681d94d7f116314c3f00167
Author: Ludovic L'Hours <ludovic lhours gmail com>
Date:   Tue Jul 21 16:28:34 2009 +0200

    Proper handling of null-ok in virtual methods
    
    https://bugzilla.gnome.org/show_bug.cgi?id=589253

 codegen/codegen.py        |    2 ++
 codegen/reversewrapper.py |   18 +++++++++++++++---
 2 files changed, 17 insertions(+), 3 deletions(-)
---
diff --git a/codegen/codegen.py b/codegen/codegen.py
index 73324a5..008f01c 100755
--- a/codegen/codegen.py
+++ b/codegen/codegen.py
@@ -615,6 +615,7 @@ class Wrapper:
                         handler, props = argtypes.matcher.get_reverse(
                             param.ptype)
                         props["direction"] = param.pdir
+                        props["nullok"] = param.pnull
                         wrapper.add_parameter(handler(wrapper,
                                                       param.pname, **props))
                     buf = reversewrapper.MemoryCodeSink()
@@ -1168,6 +1169,7 @@ class GInterfaceWrapper(GObjectWrapper):
                         handler, props = argtypes.matcher.get_reverse(
                             param.ptype)
                         props["direction"] = param.pdir
+                        props["nullok"] = param.pnull
                         wrapper.add_parameter(
                             handler(wrapper, param.pname, **props))
                     buf = reversewrapper.MemoryCodeSink()
diff --git a/codegen/reversewrapper.py b/codegen/reversewrapper.py
index ed48629..b96e12e 100644
--- a/codegen/reversewrapper.py
+++ b/codegen/reversewrapper.py
@@ -408,10 +408,22 @@ class StringParam(Parameter):
                                           % (self.name, self.name, self.name)),
                                     cleanup=("Py_XDECREF(py_%s);" % self.name))
             self.wrapper.add_pyargv_item("py_%s" % self.name, optional=True)
-        else:
+        elif self.props.get('nullok', False):
             self.wrapper.add_declaration("PyObject *py_%s;" % self.name)
-            self.wrapper.write_code(code=("py_%s = PyString_FromString(%s);" %
-                                          (self.name, self.name)),
+            self.wrapper.write_code(code=("if (%s)\n"
+                                          "    py_%s = PyString_FromString(%s);\n"
+                                          "else {\n"
+                                          "    Py_INCREF(Py_None);\n"
+                                          "    py_%s = Py_None;\n"
+                                          "}\n"
+                                          % (self.name, self.name, self.name, self.name)),
+                                    cleanup=("Py_DECREF(py_%s);" % self.name))
+            self.wrapper.add_pyargv_item("py_%s" % self.name)
+        else:
+            self.wrapper.add_declaration("PyObject *py_%s = NULL;" % self.name)
+            self.wrapper.write_code(code=("if (%s)\n"
+                                          "    py_%s = PyString_FromString(%s);\n" %
+                                          (self.name, self.name, self.name)),
                                     cleanup=("Py_DECREF(py_%s);" % self.name),
                                     failure_expression=("!py_%s" % self.name))
             self.wrapper.add_pyargv_item("py_%s" % self.name)