Merge remote-tracking branch 'upstream/master' into usermarksusermarks

1 files changed, 188 insertions, 101 deletions

diff --git a/src/nvim/eval/typval.c b/src/nvim/eval/typval.c
index 8822bb0491..05b4737206 100644
--- a/src/nvim/eval/typval.c
+++ b/src/nvim/eval/typval.c
@@ -28,9 +28,9 @@
 #include "nvim/lua/executor.h"
 #include "nvim/macros.h"
 #include "nvim/mbyte.h"
+#include "nvim/mbyte_defs.h"
 #include "nvim/memory.h"
 #include "nvim/message.h"
-#include "nvim/os/fileio.h"
 #include "nvim/os/input.h"
 #include "nvim/pos.h"
 #include "nvim/types.h"
@@ -40,6 +40,15 @@
 # include "eval/typval.c.generated.h"
 #endif
 
+static char e_string_required_for_argument_nr[]
+  = N_("E1174: String required for argument %d");
+static char e_non_empty_string_required_for_argument_nr[]
+  = N_("E1175: Non-empty string required for argument %d");
+static char e_number_required_for_argument_nr[]
+  = N_("E1210: Number required for argument %d");
+static char e_string_or_list_required_for_argument_nr[]
+  = N_("E1222: String or List required for argument %d");
+
 bool tv_in_free_unref_items = false;
 
 // TODO(ZyX-I): Remove DICT_MAXNEST, make users be non-recursive instead
@@ -317,10 +326,12 @@ void tv_list_free_list(list_T *const l)
 void tv_list_free(list_T *const l)
   FUNC_ATTR_NONNULL_ALL
 {
-  if (!tv_in_free_unref_items) {
-    tv_list_free_contents(l);
-    tv_list_free_list(l);
+  if (tv_in_free_unref_items) {
+    return;
   }
+
+  tv_list_free_contents(l);
+  tv_list_free_list(l);
 }
 
 /// Unreference a list
@@ -831,7 +842,7 @@ int tv_list_join(garray_T *const gap, list_T *const l, const char *const sep)
 }
 
 /// "join()" function
-void f_join(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+void f_join(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   if (argvars[0].v_type != VAR_LIST) {
     emsg(_(e_listreq));
@@ -855,7 +866,7 @@ void f_join(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 }
 
 /// "list2str()" function
-void f_list2str(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+void f_list2str(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   garray_T ga;
 
@@ -889,8 +900,8 @@ void tv_list_remove(typval_T *argvars, typval_T *rettv, const char *arg_errmsg)
   list_T *l;
   bool error = false;
 
-  if (var_check_lock(tv_list_locked((l = argvars[0].vval.v_list)),
-                     arg_errmsg, TV_TRANSLATE)) {
+  if (value_check_lock(tv_list_locked((l = argvars[0].vval.v_list)),
+                       arg_errmsg, TV_TRANSLATE)) {
     return;
   }
 
@@ -1016,7 +1027,7 @@ static int item_compare(const void *s1, const void *s2, bool keep_zero)
     if (sortinfo->item_compare_lc) {
       res = strcoll(p1, p2);
     } else {
-      res = sortinfo->item_compare_ic ? STRICMP(p1, p2): STRCMP(p1, p2);
+      res = sortinfo->item_compare_ic ? STRICMP(p1, p2): strcmp(p1, p2);
     }
   } else {
     double n1, n2;
@@ -1079,15 +1090,17 @@ static int item_compare2(const void *s1, const void *s2, bool keep_zero)
 
   rettv.v_type = VAR_UNKNOWN;  // tv_clear() uses this
   funcexe_T funcexe = FUNCEXE_INIT;
-  funcexe.evaluate = true;
-  funcexe.partial = partial;
-  funcexe.selfdict = sortinfo->item_compare_selfdict;
+  funcexe.fe_evaluate = true;
+  funcexe.fe_partial = partial;
+  funcexe.fe_selfdict = sortinfo->item_compare_selfdict;
   res = call_func(func_name, -1, &rettv, 2, argv, &funcexe);
   tv_clear(&argv[0]);
   tv_clear(&argv[1]);
 
   if (res == FAIL) {
+    // XXX: ITEM_COMPARE_FAIL is unused
     res = ITEM_COMPARE_FAIL;
+    sortinfo->item_compare_func_err = true;
   } else {
     res = (int)tv_get_number_chk(&rettv, &sortinfo->item_compare_func_err);
     if (res > 0) {
@@ -1143,7 +1156,7 @@ static void do_sort_uniq(typval_T *argvars, typval_T *rettv, bool sort)
     semsg(_(e_listarg), sort ? "sort()" : "uniq()");
   } else {
     list_T *const l = argvars[0].vval.v_list;
-    if (var_check_lock(tv_list_locked(l), arg_errmsg, TV_TRANSLATE)) {
+    if (value_check_lock(tv_list_locked(l), arg_errmsg, TV_TRANSLATE)) {
       goto theend;
     }
     tv_list_set_ret(rettv, l);
@@ -1242,20 +1255,18 @@ static void do_sort_uniq(typval_T *argvars, typval_T *rettv, bool sort)
         item_compare_func_ptr = item_compare_keeping_zero;
       }
 
-      int idx = 0;
       for (listitem_T *li = TV_LIST_ITEM_NEXT(l, tv_list_first(l))
            ; li != NULL;) {
         listitem_T *const prev_li = TV_LIST_ITEM_PREV(l, li);
         if (item_compare_func_ptr(&prev_li, &li) == 0) {
-          if (info.item_compare_func_err) {  // -V547
-            emsg(_("E882: Uniq compare function failed"));
-            break;
-          }
           li = tv_list_item_remove(l, li);
         } else {
-          idx++;
           li = TV_LIST_ITEM_NEXT(l, li);
         }
+        if (info.item_compare_func_err) {
+          emsg(_("E882: Uniq compare function failed"));
+          break;
+        }
       }
     }
 
@@ -1267,13 +1278,13 @@ theend:
 }
 
 /// "sort"({list})" function
-void f_sort(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+void f_sort(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   do_sort_uniq(argvars, rettv, true);
 }
 
 /// "uniq({list})" function
-void f_uniq(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+void f_uniq(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   do_sort_uniq(argvars, rettv, false);
 }
@@ -1356,7 +1367,7 @@ void tv_list_reverse(list_T *const l)
 ///               true list will not be modified. Must be initialized to false
 ///               by the caller.
 void tv_list_item_sort(list_T *const l, ListSortItem *const ptrs,
-                       const ListSorter item_compare_func, bool *errp)
+                       const ListSorter item_compare_func, const bool *errp)
   FUNC_ATTR_NONNULL_ARG(3, 4)
 {
   const int len = tv_list_len(l);
@@ -1568,7 +1579,7 @@ bool tv_callback_equal(const Callback *cb1, const Callback *cb2)
   }
   switch (cb1->type) {
   case kCallbackFuncref:
-    return STRCMP(cb1->data.funcref, cb2->data.funcref) == 0;
+    return strcmp(cb1->data.funcref, cb2->data.funcref) == 0;
   case kCallbackPartial:
     // FIXME: this is inconsistent with tv_equal but is needed for precision
     // maybe change dictwatcheradd to return a watcher id instead?
@@ -1588,7 +1599,7 @@ void callback_free(Callback *callback)
 {
   switch (callback->type) {
   case kCallbackFuncref:
-    func_unref((char_u *)callback->data.funcref);
+    func_unref(callback->data.funcref);
     xfree(callback->data.funcref);
     break;
   case kCallbackPartial:
@@ -1617,7 +1628,7 @@ void callback_put(Callback *cb, typval_T *tv)
   case kCallbackFuncref:
     tv->v_type = VAR_FUNC;
     tv->vval.v_string = xstrdup(cb->data.funcref);
-    func_ref((char_u *)cb->data.funcref);
+    func_ref(cb->data.funcref);
     break;
   case kCallbackLua:
   // TODO(tjdevries): Unified Callback.
@@ -1643,7 +1654,7 @@ void callback_copy(Callback *dest, Callback *src)
     break;
   case kCallbackFuncref:
     dest->data.funcref = xstrdup(src->data.funcref);
-    func_ref((char_u *)src->data.funcref);
+    func_ref(src->data.funcref);
     break;
   case kCallbackLua:
     dest->data.luaref = api_new_luaref(src->data.luaref);
@@ -1740,9 +1751,8 @@ static bool tv_dict_watcher_matches(DictWatcher *watcher, const char *const key)
   const size_t len = watcher->key_pattern_len;
   if (len && watcher->key_pattern[len - 1] == '*') {
     return strncmp(key, watcher->key_pattern, len - 1) == 0;
-  } else {
-    return strcmp(key, watcher->key_pattern) == 0;
   }
+  return strcmp(key, watcher->key_pattern) == 0;
 }
 
 /// Send a change notification to all dictionary watchers that match given key
@@ -1774,7 +1784,7 @@ void tv_dict_watcher_notify(dict_T *const dict, const char *const key, typval_T
     tv_dict_add(argv[2].vval.v_dict, v);
   }
 
-  if (oldtv) {
+  if (oldtv && oldtv->v_type != VAR_UNKNOWN) {
     dictitem_T *const v = tv_dict_item_alloc_len(S_LEN("old"));
     tv_copy(oldtv, &v->di_tv);
     tv_dict_add(argv[2].vval.v_dict, v);
@@ -1834,6 +1844,7 @@ dictitem_T *tv_dict_item_alloc_len(const char *const key, const size_t key_len)
   di->di_key[key_len] = NUL;
   di->di_flags = DI_FLAGS_ALLOC;
   di->di_tv.v_lock = VAR_UNLOCKED;
+  di->di_tv.v_type = VAR_UNKNOWN;
   return di;
 }
 
@@ -2053,9 +2064,24 @@ int tv_dict_get_tv(dict_T *d, const char *const key, typval_T *rettv)
 varnumber_T tv_dict_get_number(const dict_T *const d, const char *const key)
   FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
 {
+  return tv_dict_get_number_def(d, key, 0);
+}
+
+/// Get a number item from a dictionary.
+///
+/// Returns "def" if the entry doesn't exist.
+///
+/// @param[in]  d  Dictionary to get item from.
+/// @param[in]  key  Key to find in dictionary.
+/// @param[in]  def  Default value.
+///
+/// @return Dictionary item.
+varnumber_T tv_dict_get_number_def(const dict_T *const d, const char *const key, const int def)
+  FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
+{
   dictitem_T *const di = tv_dict_find(d, key, -1);
   if (di == NULL) {
-    return 0;
+    return def;
   }
   return tv_get_number(&di->di_tv);
 }
@@ -2074,7 +2100,7 @@ char **tv_dict_to_env(dict_T *denv)
   TV_DICT_ITER(denv, var, {
     const char *str = tv_get_string(&var->di_tv);
     assert(str);
-    size_t len = STRLEN(var->di_key) + strlen(str) + strlen("=") + 1;
+    size_t len = strlen((char *)var->di_key) + strlen(str) + strlen("=") + 1;
     env[i] = xmalloc(len);
     snprintf(env[i], len, "%s=%s", (char *)var->di_key, str);
     i++;
@@ -2183,6 +2209,15 @@ bool tv_dict_get_callback(dict_T *const d, const char *const key, const ptrdiff_
   return res;
 }
 
+/// Check for adding a function to g: or l:.
+/// If the name is wrong give an error message and return true.
+int tv_dict_wrong_func_name(dict_T *d, typval_T *tv, const char *name)
+{
+  return (d == &globvardict || &d->dv_hashtab == get_funccal_local_ht())
+         && tv_is_func(*tv)
+         && var_wrong_func_name(name, true);
+}
+
 //{{{2 dict_add*
 
 /// Add item to dictionary
@@ -2194,7 +2229,10 @@ bool tv_dict_get_callback(dict_T *const d, const char *const key, const ptrdiff_
 int tv_dict_add(dict_T *const d, dictitem_T *const item)
   FUNC_ATTR_NONNULL_ALL
 {
-  return hash_add(&d->dv_hashtab, item->di_key);
+  if (tv_dict_wrong_func_name(d, &item->di_tv, (const char *)item->di_key)) {
+    return FAIL;
+  }
+  return hash_add(&d->dv_hashtab, (char *)item->di_key);
 }
 
 /// Add a list entry to dictionary
@@ -2410,10 +2448,10 @@ void tv_dict_clear(dict_T *const d)
 ///
 /// @param  d1  Dictionary to extend.
 /// @param[in]  d2  Dictionary to extend with.
-/// @param[in]  action  "error", "force", "keep":
-///
+/// @param[in]  action  "error", "force", "move", "keep":
 ///                     e*, including "error": duplicate key gives an error.
 ///                     f*, including "force": duplicate d2 keys override d1.
+///                     m*, including "move": move items instead of copying.
 ///                     other, including "keep": duplicate d2 keys ignored.
 void tv_dict_extend(dict_T *const d1, dict_T *const d2, const char *const action)
   FUNC_ATTR_NONNULL_ALL
@@ -2422,27 +2460,33 @@ void tv_dict_extend(dict_T *const d1, dict_T *const d2, const char *const action
   const char *const arg_errmsg = _("extend() argument");
   const size_t arg_errmsg_len = strlen(arg_errmsg);
 
-  TV_DICT_ITER(d2, di2, {
+  if (*action == 'm') {
+    hash_lock(&d2->dv_hashtab);  // don't rehash on hash_remove()
+  }
+
+  HASHTAB_ITER(&d2->dv_hashtab, hi2, {
+    dictitem_T *const di2 = TV_DICT_HI2DI(hi2);
     dictitem_T *const di1 = tv_dict_find(d1, (const char *)di2->di_key, -1);
-    if (d1->dv_scope != VAR_NO_SCOPE) {
-      // Disallow replacing a builtin function in l: and g:.
-      // Check the key to be valid when adding to any scope.
-      if (d1->dv_scope == VAR_DEF_SCOPE
-          && tv_is_func(di2->di_tv)
-          && !var_check_func_name((const char *)di2->di_key, di1 == NULL)) {
-        break;
-      }
-      if (!valid_varname((const char *)di2->di_key)) {
-        break;
-      }
+    // Check the key to be valid when adding to any scope.
+    if (d1->dv_scope != VAR_NO_SCOPE && !valid_varname((const char *)di2->di_key)) {
+      break;
     }
     if (di1 == NULL) {
-      dictitem_T *const new_di = tv_dict_item_copy(di2);
-      if (tv_dict_add(d1, new_di) == FAIL) {
-        tv_dict_item_free(new_di);
-      } else if (watched) {
-        tv_dict_watcher_notify(d1, (const char *)new_di->di_key, &new_di->di_tv,
-                               NULL);
+      if (*action == 'm') {
+        // Cheap way to move a dict item from "d2" to "d1".
+        // If dict_add() fails then "d2" won't be empty.
+        dictitem_T *const new_di = di2;
+        if (tv_dict_add(d1, new_di) == OK) {
+          hash_remove(&d2->dv_hashtab, hi2);
+          tv_dict_watcher_notify(d1, (const char *)new_di->di_key, &new_di->di_tv, NULL);
+        }
+      } else {
+        dictitem_T *const new_di = tv_dict_item_copy(di2);
+        if (tv_dict_add(d1, new_di) == FAIL) {
+          tv_dict_item_free(new_di);
+        } else if (watched) {
+          tv_dict_watcher_notify(d1, (const char *)new_di->di_key, &new_di->di_tv, NULL);
+        }
       }
     } else if (*action == 'e') {
       semsg(_("E737: Key already exists: %s"), di2->di_key);
@@ -2450,10 +2494,14 @@ void tv_dict_extend(dict_T *const d1, dict_T *const d2, const char *const action
     } else if (*action == 'f' && di2 != di1) {
       typval_T oldtv;
 
-      if (var_check_lock(di1->di_tv.v_lock, arg_errmsg, arg_errmsg_len)
+      if (value_check_lock(di1->di_tv.v_lock, arg_errmsg, arg_errmsg_len)
           || var_check_ro(di1->di_flags, arg_errmsg, arg_errmsg_len)) {
         break;
       }
+      // Disallow replacing a builtin function.
+      if (tv_dict_wrong_func_name(d1, &di2->di_tv, (const char *)di2->di_key)) {
+        break;
+      }
 
       if (watched) {
         tv_copy(&di1->di_tv, &oldtv);
@@ -2469,6 +2517,10 @@ void tv_dict_extend(dict_T *const d1, dict_T *const d2, const char *const action
       }
     }
   });
+
+  if (*action == 'm') {
+    hash_unlock(&d2->dv_hashtab);
+  }
 }
 
 /// Compare two dictionaries
@@ -2483,10 +2535,14 @@ bool tv_dict_equal(dict_T *const d1, dict_T *const d2, const bool ic, const bool
   if (d1 == d2) {
     return true;
   }
-  if (d1 == NULL || d2 == NULL) {
+  if (tv_dict_len(d1) != tv_dict_len(d2)) {
     return false;
   }
-  if (tv_dict_len(d1) != tv_dict_len(d2)) {
+  if (tv_dict_len(d1) == 0) {
+    // empty and NULL dicts are considered equal
+    return true;
+  }
+  if (d1 == NULL || d2 == NULL) {
     return false;
   }
 
@@ -2532,8 +2588,8 @@ dict_T *tv_dict_copy(const vimconv_T *const conv, dict_T *const orig, const bool
     if (conv == NULL || conv->vc_type == CONV_NONE) {
       new_di = tv_dict_item_alloc((const char *)di->di_key);
     } else {
-      size_t len = STRLEN(di->di_key);
-      char *const key = (char *)string_convert(conv, di->di_key, &len);
+      size_t len = strlen((char *)di->di_key);
+      char *const key = (char *)string_convert(conv, (char *)di->di_key, &len);
       if (key == NULL) {
         new_di = tv_dict_item_alloc_len((const char *)di->di_key, len);
       } else {
@@ -2654,7 +2710,7 @@ void tv_blob_remove(typval_T *argvars, typval_T *rettv, const char *arg_errmsg)
 {
   blob_T *const b = argvars[0].vval.v_blob;
 
-  if (b != NULL && var_check_lock(b->bv_lock, arg_errmsg, TV_TRANSLATE)) {
+  if (b != NULL && value_check_lock(b->bv_lock, arg_errmsg, TV_TRANSLATE)) {
     return;
   }
 
@@ -2674,7 +2730,7 @@ void tv_blob_remove(typval_T *argvars, typval_T *rettv, const char *arg_errmsg)
     }
     if (argvars[2].v_type == VAR_UNKNOWN) {
       // Remove one item, return its value.
-      char_u *const p = (char_u *)b->bv_ga.ga_data;
+      uint8_t *const p = (uint8_t *)b->bv_ga.ga_data;
       rettv->vval.v_number = (varnumber_T)(*(p + idx));
       memmove(p + idx, p + idx + 1, (size_t)(len - idx - 1));
       b->bv_ga.ga_len--;
@@ -2696,9 +2752,8 @@ void tv_blob_remove(typval_T *argvars, typval_T *rettv, const char *arg_errmsg)
       blob->bv_ga.ga_len = (int)(end - idx + 1);
       ga_grow(&blob->bv_ga, (int)(end - idx + 1));
 
-      char_u *const p = (char_u *)b->bv_ga.ga_data;
-      memmove((char_u *)blob->bv_ga.ga_data, p + idx,
-              (size_t)(end - idx + 1));
+      uint8_t *const p = (uint8_t *)b->bv_ga.ga_data;
+      memmove(blob->bv_ga.ga_data, p + idx, (size_t)(end - idx + 1));
       tv_blob_set_ret(rettv, blob);
 
       if (len - end - 1 > 0) {
@@ -2777,7 +2832,7 @@ static void tv_dict_list(typval_T *const tv, typval_T *const rettv, const DictLi
     switch (what) {
       case kDictListKeys:
         tv_item.v_type = VAR_STRING;
-        tv_item.vval.v_string = (char *)vim_strsave(di->di_key);
+        tv_item.vval.v_string = xstrdup((char *)di->di_key);
         break;
       case kDictListValues:
         tv_copy(&di->di_tv, &tv_item);
@@ -2806,25 +2861,25 @@ static void tv_dict_list(typval_T *const tv, typval_T *const rettv, const DictLi
 }
 
 /// "items(dict)" function
-void f_items(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+void f_items(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   tv_dict_list(argvars, rettv, 2);
 }
 
 /// "keys()" function
-void f_keys(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+void f_keys(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   tv_dict_list(argvars, rettv, 0);
 }
 
 /// "values(dict)" function
-void f_values(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+void f_values(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   tv_dict_list(argvars, rettv, 1);
 }
 
 /// "has_key()" function
-void f_has_key(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+void f_has_key(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   if (argvars[0].v_type != VAR_DICT) {
     emsg(_(e_dictreq));
@@ -2846,7 +2901,7 @@ void tv_dict_remove(typval_T *argvars, typval_T *rettv, const char *arg_errmsg)
   if (argvars[2].v_type != VAR_UNKNOWN) {
     semsg(_(e_toomanyarg), "remove()");
   } else if ((d = argvars[0].vval.v_dict) != NULL
-             && !var_check_lock(d->dv_lock, arg_errmsg, TV_TRANSLATE)) {
+             && !value_check_lock(d->dv_lock, arg_errmsg, TV_TRANSLATE)) {
     const char *key = tv_get_string_chk(&argvars[1]);
     if (key != NULL) {
       dictitem_T *di = tv_dict_find(d, key, -1);
@@ -2951,7 +3006,7 @@ void tv_blob_copy(typval_T *const from, typval_T *const to)
     (tv)->v_lock = VAR_UNLOCKED; \
   } while (0)
 
-static inline int _nothing_conv_func_start(typval_T *const tv, char_u *const fun)
+static inline int _nothing_conv_func_start(typval_T *const tv, char *const fun)
   FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_ALWAYS_INLINE FUNC_ATTR_NONNULL_ARG(1)
 {
   tv->v_lock = VAR_UNLOCKED;
@@ -3114,6 +3169,7 @@ static inline void _nothing_conv_dict_end(typval_T *const tv, dict_T **const dic
 #define TYPVAL_ENCODE_FIRST_ARG_TYPE const void *const
 #define TYPVAL_ENCODE_FIRST_ARG_NAME ignored
 #include "nvim/eval/typval_encode.c.h"
+
 #undef TYPVAL_ENCODE_SCOPE
 #undef TYPVAL_ENCODE_NAME
 #undef TYPVAL_ENCODE_FIRST_ARG_TYPE
@@ -3178,7 +3234,7 @@ void tv_free(typval_T *tv)
       partial_unref(tv->vval.v_partial);
       break;
     case VAR_FUNC:
-      func_unref((char_u *)tv->vval.v_string);
+      func_unref(tv->vval.v_string);
       FALLTHROUGH;
     case VAR_STRING:
       xfree(tv->vval.v_string);
@@ -3231,7 +3287,7 @@ void tv_copy(const typval_T *const from, typval_T *const to)
     if (from->vval.v_string != NULL) {
       to->vval.v_string = xstrdup(from->vval.v_string);
       if (from->v_type == VAR_FUNC) {
-        func_ref((char_u *)to->vval.v_string);
+        func_ref(to->vval.v_string);
       }
     }
     break;
@@ -3403,12 +3459,12 @@ bool tv_check_lock(const typval_T *tv, const char *name, size_t name_len)
   default:
     break;
   }
-  return var_check_lock(tv->v_lock, name, name_len)
-         || (lock != VAR_UNLOCKED && var_check_lock(lock, name, name_len));
+  return value_check_lock(tv->v_lock, name, name_len)
+         || (lock != VAR_UNLOCKED && value_check_lock(lock, name, name_len));
 }
 
-/// @return true if variable "name" is locked (immutable)
-bool var_check_lock(VarLockStatus lock, const char *name, size_t name_len)
+/// @return true if variable "name" has a locked (immutable) value
+bool value_check_lock(VarLockStatus lock, const char *name, size_t name_len)
 {
   const char *error_message = NULL;
   switch (lock) {
@@ -3583,13 +3639,13 @@ bool tv_check_str_or_nr(const typval_T *const tv)
 #define FUNC_ERROR "E703: Using a Funcref as a Number"
 
 static const char *const num_errors[] = {
-  [VAR_PARTIAL]=N_(FUNC_ERROR),
-  [VAR_FUNC]=N_(FUNC_ERROR),
-  [VAR_LIST]=N_("E745: Using a List as a Number"),
-  [VAR_DICT]=N_("E728: Using a Dictionary as a Number"),
-  [VAR_FLOAT]=N_("E805: Using a Float as a Number"),
-  [VAR_BLOB]=N_("E974: Using a Blob as a Number"),
-  [VAR_UNKNOWN]=N_("E685: using an invalid value as a Number"),
+  [VAR_PARTIAL]= N_(FUNC_ERROR),
+  [VAR_FUNC]= N_(FUNC_ERROR),
+  [VAR_LIST]= N_("E745: Using a List as a Number"),
+  [VAR_DICT]= N_("E728: Using a Dictionary as a Number"),
+  [VAR_FLOAT]= N_("E805: Using a Float as a Number"),
+  [VAR_BLOB]= N_("E974: Using a Blob as a Number"),
+  [VAR_UNKNOWN]= N_("E685: using an invalid value as a Number"),
 };
 
 #undef FUNC_ERROR
@@ -3628,13 +3684,13 @@ bool tv_check_num(const typval_T *const tv)
 #define FUNC_ERROR "E729: using Funcref as a String"
 
 static const char *const str_errors[] = {
-  [VAR_PARTIAL]=N_(FUNC_ERROR),
-  [VAR_FUNC]=N_(FUNC_ERROR),
-  [VAR_LIST]=N_("E730: using List as a String"),
-  [VAR_DICT]=N_("E731: using Dictionary as a String"),
-  [VAR_FLOAT]=((const char *)e_float_as_string),
-  [VAR_BLOB]=N_("E976: using Blob as a String"),
-  [VAR_UNKNOWN]=N_("E908: using an invalid value as a String"),
+  [VAR_PARTIAL]= N_(FUNC_ERROR),
+  [VAR_FUNC]= N_(FUNC_ERROR),
+  [VAR_LIST]= N_("E730: using List as a String"),
+  [VAR_DICT]= N_("E731: using Dictionary as a String"),
+  [VAR_FLOAT]= ((const char *)e_float_as_string),
+  [VAR_BLOB]= N_("E976: using Blob as a String"),
+  [VAR_UNKNOWN]= N_("E908: using an invalid value as a String"),
 };
 
 #undef FUNC_ERROR
@@ -3717,8 +3773,7 @@ varnumber_T tv_get_number_chk(const typval_T *const tv, bool *const ret_error)
   case VAR_STRING: {
     varnumber_T n = 0;
     if (tv->vval.v_string != NULL) {
-      vim_str2nr((char_u *)tv->vval.v_string, NULL, NULL, STR2NR_ALL, &n, NULL, 0,
-                 false);
+      vim_str2nr(tv->vval.v_string, NULL, NULL, STR2NR_ALL, &n, NULL, 0, false);
     }
     return n;
   }
@@ -3746,9 +3801,11 @@ varnumber_T tv_get_number_chk(const typval_T *const tv, bool *const ret_error)
 linenr_T tv_get_lnum(const typval_T *const tv)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT
 {
+  const int did_emsg_before = did_emsg;
   linenr_T lnum = (linenr_T)tv_get_number_chk(tv, NULL);
-  if (lnum == 0) {  // No valid number, try using same function as line() does.
+  if (lnum <= 0 && did_emsg_before == did_emsg && tv->v_type != VAR_NUMBER) {
     int fnum;
+    // No valid number, try using same function as line() does.
     pos_T *const fp = var2fpos(tv, true, &fnum, false);
     if (fp != NULL) {
       lnum = fp->lnum;
@@ -3801,26 +3858,56 @@ float_T tv_get_float(const typval_T *const tv)
   return 0;
 }
 
-// Give an error and return FAIL unless "tv" is a string.
-int tv_check_for_string(const typval_T *const tv)
+/// Give an error and return FAIL unless "args[idx]" is a string.
+int tv_check_for_string_arg(const typval_T *const args, const int idx)
+  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
+{
+  if (args[idx].v_type != VAR_STRING) {
+    semsg(_(e_string_required_for_argument_nr), idx + 1);
+    return FAIL;
+  }
+  return OK;
+}
+
+/// Give an error and return FAIL unless "args[idx]" is a non-empty string.
+int tv_check_for_nonempty_string_arg(const typval_T *const args, const int idx)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
 {
-  if (tv->v_type != VAR_STRING) {
-    emsg(_(e_stringreq));
+  if (tv_check_for_string_arg(args, idx) == FAIL) {
+    return FAIL;
+  }
+  if (args[idx].vval.v_string == NULL || *args[idx].vval.v_string == NUL) {
+    semsg(_(e_non_empty_string_required_for_argument_nr), idx + 1);
     return FAIL;
   }
   return OK;
 }
 
-// Give an error and return FAIL unless "tv" is a non-empty string.
-int tv_check_for_nonempty_string(const typval_T *const tv)
+/// Give an error and return FAIL unless "args[idx]" is a number.
+int tv_check_for_number_arg(const typval_T *const args, const int idx)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
 {
-  if (tv_check_for_string(tv) == FAIL) {
+  if (args[idx].v_type != VAR_NUMBER) {
+    semsg(_(e_number_required_for_argument_nr), idx + 1);
     return FAIL;
   }
-  if (tv->vval.v_string == NULL || *tv->vval.v_string == NUL) {
-    emsg(_(e_non_empty_string_required));
+  return OK;
+}
+
+/// Check for an optional number argument at "idx"
+int tv_check_for_opt_number_arg(const typval_T *const args, const int idx)
+  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
+{
+  return (args[idx].v_type == VAR_UNKNOWN
+          || tv_check_for_number_arg(args, idx) != FAIL) ? OK : FAIL;
+}
+
+/// Give an error and return FAIL unless "args[idx]" is a string or a list.
+int tv_check_for_string_or_list_arg(const typval_T *const args, const int idx)
+  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
+{
+  if (args[idx].v_type != VAR_STRING && args[idx].v_type != VAR_LIST) {
+    semsg(_(e_string_or_list_required_for_argument_nr), idx + 1);
     return FAIL;
   }
   return OK;