Process exception during the callback

As process exception may raise an exception, it should be run in the callback
to let the caller catch it. Otherwise it is raised in the thread and never
catch.

issue6907
review42811003

tryton/common/common.py

@@ -1191,17 +1191,15 @@ class RPCProgress(object):
     def process(self):
         if self.parent and self.parent.get_window():
             self.parent.get_window().set_cursor(None)
-        if self.exception:
-            if self.process_exception_p:
-                def rpc_execute(*args):
-                    return RPCProgress('execute',
-                        args).run(self.process_exception_p, self.callback)
-                return process_exception(self.exception, *self.args,
-                    rpc_execute=rpc_execute)
 
         def return_():
             if self.exception:
-                raise self.exception
+                if self.process_exception_p:
+                    def rpc_execute(*args):
+                        return RPCProgress('execute',
+                            args).run(self.process_exception_p, self.callback)
+                    return process_exception(self.exception, *self.args,
+                        rpc_execute=rpc_execute)
             else:
                 return self.res