[pybank] Improve error reporting in invoke() and return None when function has no return value.

[Johan Dahlin <johan src gnome org>]

commit a01cbc4204f20e37f45a413c233bb55ecdb70c0d
Author: Tomeu Vizoso <tomeu sugarlabs org>
Date:   Fri May 8 11:50:35 2009 +0200

    Improve error reporting in invoke() and return None when function has no return value.
---
 bank/bank-info.c |   32 +++++++++++++++++---------------
 1 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/bank/bank-info.c b/bank/bank-info.c
index e751584..21ecd6c 100644
--- a/bank/bank-info.c
+++ b/bank/bank-info.c
@@ -400,8 +400,10 @@ _wrap_g_function_info_invoke(PyGIBaseInfo *self, PyObject *args)
         GIInfoType type = g_base_info_get_type(container);
 
         py_arg = PyTuple_GetItem(args, 0);
-        if (!py_arg)
+        if (!py_arg) {
+            PyErr_SetString(PyExc_ValueError, "Calling a method without passing an instance");
             return NULL;
+        }
         if (py_arg == Py_None)
             in_args[0].v_pointer = NULL;
         else if (type == GI_INFO_TYPE_STRUCT || type == GI_INFO_TYPE_BOXED) {
@@ -456,7 +458,7 @@ _wrap_g_function_info_invoke(PyGIBaseInfo *self, PyObject *args)
     }
 
     if (failed) {
-	g_error("Failed to convert all args.");
+        PyErr_SetString(PyExc_ValueError, "Failed to convert all args.");
         return NULL;
     }
 
@@ -470,11 +472,6 @@ _wrap_g_function_info_invoke(PyGIBaseInfo *self, PyObject *args)
                                         &return_arg,
                                         &error);
 
-    /* Return value and out arguments are valid only if invocation doesn't
-     * return error. In arguments need to be released always.
-     */
-    failed = FALSE;
-
     return_info = g_callable_info_get_return_type( (GICallableInfo*) self->info);
     g_assert(return_info != NULL);
 
@@ -563,18 +560,23 @@ _wrap_g_function_info_invoke(PyGIBaseInfo *self, PyObject *args)
     g_base_info_unref( (GIBaseInfo*) return_info);
 
     if (invoke_ok) {
-        return failed ? NULL : retval;
+        if (retval == NULL) {
+            Py_INCREF(Py_None);
+            return Py_None;
+        } else
+            return retval;
     } else {
+        char buf[256];
+        snprintf(buf, sizeof(buf), "Error invoking %s.%s: %s",
+                 g_base_info_get_namespace( (GIBaseInfo*) self->info),
+                 g_base_info_get_name( (GIBaseInfo*) self->info),
+                 error->message);
+
         g_assert(error != NULL);
-        g_error("Error invoking %s.%s: %s",
-                g_base_info_get_namespace( (GIBaseInfo*) self->info),
-                g_base_info_get_name( (GIBaseInfo*) self->info),
-                error->message);
+        PyErr_SetString(PyExc_RuntimeError, buf);
         g_error_free(error);
 
-	retval = Py_None;
-	Py_INCREF(retval);
-        return retval;
+        return NULL;
     }
 }