refactor(options)!: unify `set_option` and `set_string_option`

While the interfaces for setting number and boolean options are now unified by #25394, there is still a separate `set_string_option` function that is used for setting a string option. This PR removes that function and merges it with set_option.

BREAKING CHANGE: `v:option_old` is now the old global value for all global-local options, instead of just string global-local options. Local value for a global-local number/boolean option is now unset when the option is set (e.g. using `:set` or `nvim_set_option_value`) without a scope, which means they now behave the same way as string options.

Ref: #25672

1 files changed, 0 insertions, 15 deletions

diff --git a/src/nvim/api/deprecated.c b/src/nvim/api/deprecated.c
index 31ba20f627..59b7fc18d6 100644
--- a/src/nvim/api/deprecated.c
+++ b/src/nvim/api/deprecated.c
@@ -681,21 +681,6 @@ static void set_option_to(uint64_t channel_id, void *to, OptReqScope req_scope,
     return;
   });
 
-  if (value.type == kObjectTypeNil) {
-    if (req_scope == kOptReqGlobal) {
-      api_set_error(err, kErrorTypeException, "Cannot unset option '%s'", name.data);
-      return;
-    } else if (!(flags & SOPT_GLOBAL)) {
-      api_set_error(err, kErrorTypeException,
-                    "Cannot unset option '%s' because it doesn't have a global value",
-                    name.data);
-      return;
-    } else {
-      unset_global_local_option(name.data, to);
-      return;
-    }
-  }
-
   bool error = false;
   OptVal optval = object_as_optval(value, &error);