lib/filterx: fix variable lookup

A non-floating (i.e., tied to a LogMessage) FilterX variable is considered invalid if:
- its' generation counter is 0 AND
- the scope is syncable

This is to allow two consecutive FilterX blocks to pass non-floating variables
without calling filterx_scope_sync().
If they would be considered invalid then the changes would be lost in the latter block.
This is because it would fetch it via _pull_variable_from_message() which would
yield the unmodified LogMessageValue.

Signed-off-by: Szilard Parrag <[email protected]>

lib/filterx/filterx-scope.c

@@ -191,6 +191,8 @@ filterx_scope_lookup_variable(FilterXScope *self, FilterXVariableHandle handle)
       if (filterx_variable_handle_is_floating(handle) &&
           !v->declared && v->generation != self->generation)
         return NULL;
+      if (!filterx_variable_handle_is_floating(handle) && v->generation == 0 && self->syncable)
+        return NULL;
       return v;
     }
   return NULL;