1 files changed, 28 insertions, 6 deletions
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index 9279f6b469..46ac3c9022 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -116,8 +116,14 @@ String vim_replace_termcodes(String str, Boolean from_part, Boolean do_lt,
   }
 
   char *ptr = NULL;
-  replace_termcodes((char_u *)str.data, (char_u **)&ptr,
-                                            from_part, do_lt, special);
+  // Set 'cpoptions' the way we want it.
+  //    FLAG_CPO_BSLASH  set - backslashes are *not* treated specially
+  //    FLAG_CPO_KEYCODE set - keycodes are *not* reverse-engineered
+  //    FLAG_CPO_SPECI unset - <Key> sequences *are* interpreted
+  //  The third from end parameter of replace_termcodes() is true so that the
+  //  <lt> sequence is recognised - needed for a real backslash.
+  replace_termcodes((char_u *)str.data, str.size, (char_u **)&ptr,
+                    from_part, do_lt, special, CPO_TO_CPO_FLAGS);
   return cstr_as_string(ptr);
 }
 
@@ -291,7 +297,7 @@ void vim_change_directory(String dir, Error *err)
     return;
   }
 
-  post_chdir(false);
+  post_chdir(kCdScopeGlobal);
   try_end(err);
 }
 
@@ -331,15 +337,31 @@ Object vim_get_var(String name, Error *err)
   return dict_get_value(&globvardict, name, err);
 }
 
-/// Sets a global variable. Passing 'nil' as value deletes the variable.
+/// Sets a global variable
 ///
 /// @param name The variable name
 /// @param value The variable value
 /// @param[out] err Details of an error that may have occurred
-/// @return the old value if any
+/// @return The old value or nil if there was no previous value.
+///
+///         @warning It may return nil if there was no previous value
+///                  or if previous value was `v:null`.
 Object vim_set_var(String name, Object value, Error *err)
 {
-  return dict_set_value(&globvardict, name, value, err);
+  return dict_set_value(&globvardict, name, value, false, err);
+}
+
+/// Removes a global variable
+///
+/// @param name The variable name
+/// @param[out] err Details of an error that may have occurred
+/// @return The old value or nil if there was no previous value.
+///
+///         @warning It may return nil if there was no previous value
+///                  or if previous value was `v:null`.
+Object vim_del_var(String name, Error *err)
+{
+  return dict_set_value(&globvardict, name, NIL, true, err);
 }
 
 /// Gets a vim variable