patch 8.1.1320: it is not possible to track changes to a buffer
Problem: It is not possible to track changes to a buffer.
Solution: Add listener_add() and listener_remove(). No docs or tests yet.
diff --git a/src/proto/change.pro b/src/proto/change.pro
index 34733f5..4e8a1e6 100644
--- a/src/proto/change.pro
+++ b/src/proto/change.pro
@@ -2,6 +2,9 @@
void change_warning(int col);
void changed(void);
void changed_internal(void);
+void f_listener_add(typval_T *argvars, typval_T *rettv);
+void f_listener_remove(typval_T *argvars, typval_T *rettv);
+void invoke_listeners(void);
void changed_bytes(linenr_T lnum, colnr_T col);
void inserted_bytes(linenr_T lnum, colnr_T col, int added);
void appended_lines(linenr_T lnum, long count);