minor changes needed for the next commit.

- BKE_add_image_extension now sets the extension rather then appending. (no more image.jpg.tga)
- py/rna functions which have no return value now raise an error if a non-None value is returned.
- added back the red-alert flag so buttons can have a red highlight if somethings wrong.

source/blender/blenkernel/BKE_image.h

@@ -48,7 +48,7 @@ void	BKE_stamp_info(struct Scene *scene, struct ImBuf *ibuf);
 void	BKE_stamp_buf(struct Scene *scene, unsigned char *rect, float *rectf, int width, int height, int channels);
 int		BKE_write_ibuf(struct Scene *scene, struct ImBuf *ibuf, char *name, int imtype, int subimtype, int quality);
 void	BKE_makepicstring(char *string, char *base, int frame, int imtype, int use_ext);
-void	BKE_add_image_extension(char *string, int imtype);
+int		BKE_add_image_extension(char *string, int imtype);
 int		BKE_ftype_to_imtype(int ftype);
 int		BKE_imtype_to_ftype(int imtype);
 int		BKE_imtype_is_movie(int imtype);

source/blender/blenkernel/intern/image.c

@@ -757,9 +757,9 @@ int BKE_imtype_is_movie(int imtype)
 	return 0;
 }
 
-void BKE_add_image_extension(char *string, int imtype)
+int BKE_add_image_extension(char *string, int imtype)
 {
-	char *extension="";
+	char *extension= NULL;
 	
 	if(imtype== R_IRIS) {
 		if(!BLI_testextensie(string, ".rgb"))
@@ -830,7 +830,12 @@ void BKE_add_image_extension(char *string, int imtype)
 			extension= ".jpg";
 	}
 
-	strcat(string, extension);
+	if(extension) {
+		return BLI_replace_extension(string, FILE_MAX, extension);
+	}
+	else {
+		return FALSE;
+	}
 }
 
 /* could allow access externally - 512 is for long names, 64 is for id names */

source/blender/editors/include/UI_interface.h

@@ -146,15 +146,16 @@ typedef struct uiLayout uiLayout;
 #define UI_BUT_ANIMATED		(1<<20)
 #define UI_BUT_ANIMATED_KEY	(1<<21)
 #define UI_BUT_DRIVEN		(1<<22)
-#define UI_BUT_INACTIVE		(1<<23)
-#define UI_BUT_LAST_ACTIVE	(1<<24)
-#define UI_BUT_UNDO			(1<<25)
-#define UI_BUT_IMMEDIATE	(1<<26)
-#define UI_BUT_NO_TOOLTIP	(1<<27)
-#define UI_BUT_NO_UTF8		(1<<28)
+#define UI_BUT_REDALERT		(1<<23)
+#define UI_BUT_INACTIVE		(1<<24)
+#define UI_BUT_LAST_ACTIVE	(1<<25)
+#define UI_BUT_UNDO			(1<<26)
+#define UI_BUT_IMMEDIATE	(1<<27)
+#define UI_BUT_NO_TOOLTIP	(1<<28)
+#define UI_BUT_NO_UTF8		(1<<29)
 
-#define UI_BUT_VEC_SIZE_LOCK (1<<29) /* used to flag if color hsv-circle should keep luminance */
-#define UI_BUT_COLOR_CUBIC	(1<<30) /* cubic saturation for the color wheel */
+#define UI_BUT_VEC_SIZE_LOCK (1<<30) /* used to flag if color hsv-circle should keep luminance */
+#define UI_BUT_COLOR_CUBIC	(1<<31) /* cubic saturation for the color wheel */
 
 #define UI_PANEL_WIDTH			340
 #define UI_COMPACT_PANEL_WIDTH	160

source/blender/editors/interface/interface_widgets.c

@@ -1437,6 +1437,11 @@ static void widget_state(uiWidgetType *wt, int state)
 			wt->wcol.inner[2]= wt->wcol.inner[2]>=240? 255 : wt->wcol.inner[2]+15;
 		}
 	}
+
+	if(state & UI_BUT_REDALERT) {
+		char red[4]= {255, 0, 0};
+		widget_state_blend(wt->wcol.inner, red, 0.4f);
+	}
 }
 
 /* sliders use special hack which sets 'item' as inner when drawing filling */

source/blender/python/intern/bpy_rna.c

@@ -5121,13 +5121,17 @@ static int bpy_class_call(PointerRNA *ptr, FunctionRNA *func, ParameterList *par
 		err= -1;
 	}
 	else {
-		if(ret_len==1) {
+		if(ret_len==0 && ret != Py_None) {
+			PyErr_Format(PyExc_RuntimeError, "expected class %.200s, function %.200s to return None, got a %.200s type instead.", RNA_struct_identifier(ptr->type), RNA_function_identifier(func), Py_TYPE(ret)->tp_name);
+			err= -1;
+		}
+		else if(ret_len==1) {
 			err= pyrna_py_to_prop(&funcptr, pret_single, parms, retdata_single, ret, "calling class function:");
 		}
 		else if (ret_len > 1) {
 
 			if(PyTuple_Check(ret)==0) {
-				PyErr_Format(PyExc_RuntimeError, "expected class %.200s, function %.200s to return a tuple of size %d.", RNA_struct_identifier(ptr->type), RNA_function_identifier(func), ret_len);
+				PyErr_Format(PyExc_RuntimeError, "expected class %.200s, function %.200s to return a tuple of size %d, got a %.200s type instead.", RNA_struct_identifier(ptr->type), RNA_function_identifier(func), ret_len, Py_TYPE(ret)->tp_name);
 				err= -1;
 			}
 			else if (PyTuple_GET_SIZE(ret) != ret_len) {