python modules in the game engine could point to builtin modules like GameLogic that was cleared.

I added module clearing before there was checks for invalid python objects, so now its not needed for BGE Builtin types at least.

also made the builtin modules get re-used if they already exist and clear all user modules when the game engine finishes so with Module-Py-Controllers the referenced modules are at least up to date when pressing Pkey.

source/blender/python/api2_2x/bpy_internal_import.c

@@ -272,7 +272,12 @@ PyMethodDef bpy_reload_meth[] = { {"bpy_reload_meth", blender_reload, METH_VARAR
  * Its also needed for the BGE Python api so imported scripts are not used between levels
  * 
  * This clears every modules that has a __file__ attribute (is not a builtin)
- * and is a filename only (no path). since pythons bultins include a full path even for win32.
+ *
+ * Note that clearing external python modules is important for the BGE otherwise
+ * it wont reload scripts between loading different blend files or while making the game.
+ * - use 'clear_all' arg in this case.
+ *
+ * Since pythons bultins include a full path even for win32.
  * even if we remove a python module a reimport will bring it back again.
  */
 
@@ -284,7 +289,7 @@ PyMethodDef bpy_reload_meth[] = { {"bpy_reload_meth", blender_reload, METH_VARAR
 #endif
 
 
-void bpy_text_clear_modules(void)
+void bpy_text_clear_modules(int clear_all)
 {
 	PyObject *modules= PySys_GetObject("modules");
 	
@@ -309,7 +314,7 @@ void bpy_text_clear_modules(void)
 	while (PyDict_Next(modules, &pos, &key, &value)) {
 		fname= PyModule_GetFilename(value);
 		if(fname) {
-			if ((strstr(fname, SEPSTR))==0) { /* no path ? */
+			if (clear_all || ((strstr(fname, SEPSTR))==0)) { /* no path ? */
 				file_extension = strstr(fname, ".py");
 				if(file_extension && *(file_extension + 3) == '\0') { /* .py extension ? */
 					/* now we can be fairly sure its a python import from the blendfile */

source/blender/python/api2_2x/bpy_internal_import.h

@@ -37,7 +37,7 @@
 
 PyObject*	bpy_text_import( char *name, int *found );
 PyObject*	bpy_text_reimport( PyObject *module, int *found );
-void		bpy_text_clear_modules( void ); /* Clear user modules */
+void		bpy_text_clear_modules( int clear_all ); /* Clear user modules */
 extern PyMethodDef bpy_import_meth[];
 extern PyMethodDef bpy_reload_meth[];