Handle GI_TRANSFER_EVERYTHING for returns of foreign structures

Any (transfer full) return of a cairo type other than a path
was leaked.

Pass the transfer type PyGIArgOverrideFromGIArgumentFunc and handle
it for the cairo foreign type. For paths we can only handle
(transfer full) so throw an error for (transfer none).

https://bugzilla.gnome.org/show_bug.cgi?id=726206

6 files changed, 31 insertions, 8 deletions

diff --git a/gi/pygi-foreign-cairo.c b/gi/pygi-foreign-cairo.c
index 3fe6a39c..8261a07f 100644
--- a/gi/pygi-foreign-cairo.c
+++ b/gi/pygi-foreign-cairo.c
@@ -56,11 +56,14 @@ cairo_context_to_arg (PyObject        *value,
 }
 
 static PyObject *
-cairo_context_from_arg (GIInterfaceInfo *interface_info, gpointer data)
+cairo_context_from_arg (GIInterfaceInfo *interface_info,
+                        GITransfer       transfer,
+                        gpointer         data)
 {
     cairo_t *context = (cairo_t*) data;
 
-    cairo_reference (context);
+    if (transfer == GI_TRANSFER_NOTHING)
+        cairo_reference (context);
 
     return PycairoContext_FromContext (context, &PycairoContext_Type, NULL);
 }
@@ -95,11 +98,14 @@ cairo_surface_to_arg (PyObject        *value,
 }
 
 static PyObject *
-cairo_surface_from_arg (GIInterfaceInfo *interface_info, gpointer data)
+cairo_surface_from_arg (GIInterfaceInfo *interface_info,
+                        GITransfer       transfer,
+                        gpointer         data)
 {
     cairo_surface_t *surface = (cairo_surface_t*) data;
 
-    cairo_surface_reference (surface);
+    if (transfer == GI_TRANSFER_NOTHING)
+        cairo_surface_reference (surface);
 
     return PycairoSurface_FromSurface (surface, NULL);
 }
@@ -134,10 +140,17 @@ cairo_path_to_arg (PyObject        *value,
 }
 
 static PyObject *
-cairo_path_from_arg (GIInterfaceInfo *interface_info, gpointer data)
+cairo_path_from_arg (GIInterfaceInfo *interface_info,
+                     GITransfer       transfer,
+                     gpointer         data)
 {
     cairo_path_t *path = (cairo_path_t*) data;
 
+    if (transfer == GI_TRANSFER_NOTHING) {
+        PyErr_SetString(PyExc_TypeError, "Unsupported annotation (transfer none) for cairo.Path return");
+        return NULL;
+    }
+
     return PycairoPath_FromPath (path);
 }
 
@@ -170,11 +183,16 @@ cairo_font_options_to_arg (PyObject        *value,
 }
 
 static PyObject *
-cairo_font_options_from_arg (GIInterfaceInfo *interface_info, gpointer data)
+cairo_font_options_from_arg (GIInterfaceInfo *interface_info,
+                             GITransfer       transfer,
+                             gpointer         data)
 {
     cairo_font_options_t *font_options = (cairo_font_options_t*) data;
 
-    return PycairoFontOptions_FromFontOptions (cairo_font_options_copy (font_options));
+    if (transfer == GI_TRANSFER_NOTHING)
+        font_options = cairo_font_options_copy (font_options);
+
+    return PycairoFontOptions_FromFontOptions (font_options);
 }
 
 static PyObject *
diff --git a/gi/pygi-foreign.c b/gi/pygi-foreign.c
index c046d0fa..f3c1a344 100644
--- a/gi/pygi-foreign.c
+++ b/gi/pygi-foreign.c
@@ -123,6 +123,7 @@ pygi_struct_foreign_convert_to_g_argument (PyObject        *value,
 
 PyObject *
 pygi_struct_foreign_convert_from_g_argument (GIInterfaceInfo *interface_info,
+                                             GITransfer       transfer,
                                              GIArgument      *arg)
 {
     GIBaseInfo *base_info = (GIBaseInfo *) interface_info;
@@ -131,7 +132,7 @@ pygi_struct_foreign_convert_from_g_argument (GIInterfaceInfo *interface_info,
     if (foreign_struct == NULL)
         return NULL;
 
-    return foreign_struct->from_func (interface_info, arg);
+    return foreign_struct->from_func (interface_info, transfer, arg);
 }
 
 PyObject *
diff --git a/gi/pygi-foreign.h b/gi/pygi-foreign.h
index dd5f8967..478d7594 100644
--- a/gi/pygi-foreign.h
+++ b/gi/pygi-foreign.h
@@ -35,6 +35,7 @@ PyObject *pygi_struct_foreign_convert_to_g_argument (PyObject           *value,
                                                      GITransfer          transfer,
                                                      GIArgument         *arg);
 PyObject *pygi_struct_foreign_convert_from_g_argument (GIInterfaceInfo *interface_info,
+                                                       GITransfer       transfer,
                                                        GIArgument      *arg);
 PyObject *pygi_struct_foreign_release (GITypeInfo *type_info,
                                        gpointer struct_);
diff --git a/gi/pygi-invoke.c b/gi/pygi-invoke.c
index 3bb4dc6c..f4abb266 100644
--- a/gi/pygi-invoke.c
+++ b/gi/pygi-invoke.c
@@ -401,6 +401,7 @@ _caller_alloc (PyGIArgCache *arg_cache, GIArgument *arg)
             PyObject *foreign_struct =
                 pygi_struct_foreign_convert_from_g_argument (
                     iface_cache->interface_info,
+                    GI_TRANSFER_NOTHING,
                     NULL);
 
                 pygi_struct_foreign_convert_to_g_argument (foreign_struct,
diff --git a/gi/pygi-struct-marshal.c b/gi/pygi-struct-marshal.c
index 338f2be5..7346eae0 100644
--- a/gi/pygi-struct-marshal.c
+++ b/gi/pygi-struct-marshal.c
@@ -352,6 +352,7 @@ _pygi_marshal_to_py_interface_struct (GIArgument *arg,
         py_obj = pyg_value_as_pyobject (arg->v_pointer, FALSE);
     } else if (is_foreign) {
         py_obj = pygi_struct_foreign_convert_from_g_argument (interface_info,
+                                                              transfer,
                                                               arg->v_pointer);
     } else if (g_type_is_a (g_type, G_TYPE_BOXED)) {
         if (py_type) {
diff --git a/gi/pygi.h b/gi/pygi.h
index 3a1591f8..ecd3359c 100644
--- a/gi/pygi.h
+++ b/gi/pygi.h
@@ -85,6 +85,7 @@ typedef PyObject * (*PyGIArgOverrideToGIArgumentFunc) (PyObject        *value,
                                                        GITransfer       transfer,
                                                        GIArgument      *arg);
 typedef PyObject * (*PyGIArgOverrideFromGIArgumentFunc) (GIInterfaceInfo *interface_info,
+                                                         GITransfer       transfer,
                                                          gpointer         data);
 typedef PyObject * (*PyGIArgOverrideReleaseFunc) (GITypeInfo *type_info,
                                                   gpointer  struct_);