1 files changed, 60 insertions, 21 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 219bd38d82..22ff7988f3 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -2890,9 +2890,12 @@ static int do_unlet_var(lval_T *lp, char_u *name_end, int forceit)
     else if (do_unlet(lp->ll_name, forceit) == FAIL)
       ret = FAIL;
     *name_end = cc;
-  } else if (tv_check_lock(lp->ll_tv->v_lock, lp->ll_name))
+  } else if ((lp->ll_list != NULL
+              && tv_check_lock(lp->ll_list->lv_lock, lp->ll_name))
+             || (lp->ll_dict != NULL
+                 && tv_check_lock(lp->ll_dict->dv_lock, lp->ll_name))) {
     return FAIL;
-  else if (lp->ll_range) {
+  } else if (lp->ll_range) {
     listitem_T    *li;
     listitem_T *ll_li = lp->ll_li;
     int ll_n1 = lp->ll_n1;
@@ -2953,17 +2956,30 @@ int do_unlet(char_u *name, int forceit)
   hashtab_T   *ht;
   hashitem_T  *hi;
   char_u      *varname;
+  dict_T      *d;
   dictitem_T  *di;
   dict_T *dict;
   ht = find_var_ht_dict(name, &varname, &dict);
 
   if (ht != NULL && *varname != NUL) {
+    if (ht == &globvarht) {
+      d = &globvardict;
+    } else if (current_funccal != NULL
+               && ht == &current_funccal->l_vars.dv_hashtab) {
+      d = &current_funccal->l_vars;
+    } else {
+      di = find_var_in_ht(ht, *name, (char_u *)"", false);
+      d = di->di_tv.vval.v_dict;
+    }
+
     hi = hash_find(ht, varname);
     if (!HASHITEM_EMPTY(hi)) {
       di = HI2DI(hi);
       if (var_check_fixed(di->di_flags, name)
-          || var_check_ro(di->di_flags, name))
+          || var_check_ro(di->di_flags, name)
+          || tv_check_lock(d->dv_lock, name)) {
         return FAIL;
+      }
       typval_T oldtv;
       bool watched = is_watched(dict);
 
@@ -6055,7 +6071,7 @@ dictitem_T *dictitem_alloc(char_u *key) FUNC_ATTR_NONNULL_RET
 #ifndef __clang_analyzer__
   STRCPY(di->di_key, key);
 #endif
-  di->di_flags = 0;
+  di->di_flags = DI_FLAGS_ALLOC;
   return di;
 }
 
@@ -6067,7 +6083,7 @@ static dictitem_T *dictitem_copy(dictitem_T *org) FUNC_ATTR_NONNULL_RET
   dictitem_T *di = xmalloc(sizeof(dictitem_T) + STRLEN(org->di_key));
 
   STRCPY(di->di_key, org->di_key);
-  di->di_flags = 0;
+  di->di_flags = DI_FLAGS_ALLOC;
   copy_tv(&org->di_tv, &di->di_tv);
 
   return di;
@@ -6095,7 +6111,9 @@ static void dictitem_remove(dict_T *dict, dictitem_T *item)
 void dictitem_free(dictitem_T *item)
 {
   clear_tv(&item->di_tv);
-  xfree(item);
+  if (item->di_flags & DI_FLAGS_ALLOC) {
+    xfree(item);
+  }
 }
 
 /// Make a copy of dictionary
@@ -9212,6 +9230,7 @@ void dict_extend(dict_T *d1, dict_T *d2, char_u *action)
   hashitem_T  *hi2;
   int todo;
   bool watched = is_watched(d1);
+  char *arg_errmsg = N_("extend() argument");
 
   todo = (int)d2->dv_hashtab.ht_used;
   for (hi2 = d2->dv_hashtab.ht_array; todo > 0; ++hi2) {
@@ -9245,6 +9264,11 @@ void dict_extend(dict_T *d1, dict_T *d2, char_u *action)
       } else if (*action == 'f' && HI2DI(hi2) != di1) {
         typval_T oldtv;
 
+        if (tv_check_lock(di1->di_tv.v_lock, (char_u *)_(arg_errmsg))
+            || var_check_ro(di1->di_flags, (char_u *)_(arg_errmsg))) {
+          break;
+        }
+
         if (watched) {
           copy_tv(&di1->di_tv, &oldtv);
         }
@@ -9460,12 +9484,14 @@ static void filter_map(typval_T *argvars, typval_T *rettv, int map)
 
   if (argvars[0].v_type == VAR_LIST) {
     if ((l = argvars[0].vval.v_list) == NULL
-        || tv_check_lock(l->lv_lock, (char_u *)_(arg_errmsg)))
+        || (!map && tv_check_lock(l->lv_lock, (char_u *)_(arg_errmsg)))) {
       return;
+    }
   } else if (argvars[0].v_type == VAR_DICT) {
     if ((d = argvars[0].vval.v_dict) == NULL
-        || tv_check_lock(d->dv_lock, (char_u *)_(arg_errmsg)))
+        || (!map && tv_check_lock(d->dv_lock, (char_u *)_(arg_errmsg)))) {
       return;
+    }
   } else {
     EMSG2(_(e_listdictarg), ermsg);
     return;
@@ -9494,17 +9520,26 @@ static void filter_map(typval_T *argvars, typval_T *rettv, int map)
       for (hi = ht->ht_array; todo > 0; ++hi) {
         if (!HASHITEM_EMPTY(hi)) {
           --todo;
+
           di = HI2DI(hi);
-          if (tv_check_lock(di->di_tv.v_lock,
-                  (char_u *)_(arg_errmsg)))
+          if (map
+              && (tv_check_lock(di->di_tv.v_lock, (char_u *)_(arg_errmsg))
+                  || var_check_ro(di->di_flags, (char_u *)_(arg_errmsg)))) {
             break;
+          }
+
           vimvars[VV_KEY].vv_str = vim_strsave(di->di_key);
           int r = filter_map_one(&di->di_tv, expr, map, &rem);
           clear_tv(&vimvars[VV_KEY].vv_tv);
           if (r == FAIL || did_emsg)
             break;
-          if (!map && rem)
+          if (!map && rem) {
+            if (var_check_fixed(di->di_flags, (char_u *)_(arg_errmsg))
+                || var_check_ro(di->di_flags, (char_u *)_(arg_errmsg))) {
+              break;
+            }
             dictitem_remove(d, di);
+          }
         }
       }
       hash_unlock(ht);
@@ -9512,8 +9547,9 @@ static void filter_map(typval_T *argvars, typval_T *rettv, int map)
       vimvars[VV_KEY].vv_type = VAR_NUMBER;
 
       for (li = l->lv_first; li != NULL; li = nli) {
-        if (tv_check_lock(li->li_tv.v_lock, (char_u *)_(arg_errmsg)))
+        if (map && tv_check_lock(li->li_tv.v_lock, (char_u *)_(arg_errmsg))) {
           break;
+        }
         nli = li->li_next;
         vimvars[VV_KEY].vv_nr = idx;
         if (filter_map_one(&li->li_tv, expr, map, &rem) == FAIL
@@ -13878,9 +13914,10 @@ static void f_remove(typval_T *argvars, typval_T *rettv)
       key = get_tv_string_chk(&argvars[1]);
       if (key != NULL) {
         di = dict_find(d, key, -1);
-        if (di == NULL)
+        if (di == NULL) {
           EMSG2(_(e_dictkey), key);
-        else {
+        } else if (!var_check_fixed(di->di_flags, (char_u *)_(arg_errmsg))
+                   && !var_check_ro(di->di_flags, (char_u *)_(arg_errmsg))) {
           *rettv = di->di_tv;
           init_tv(&di->di_tv);
           dictitem_remove(d, di);
@@ -18648,14 +18685,16 @@ static void vars_clear_ext(hashtab_T *ht, int free_val)
     if (!HASHITEM_EMPTY(hi)) {
       --todo;
 
-      /* Free the variable.  Don't remove it from the hashtab,
-       * ht_array might change then.  hash_clear() takes care of it
-       * later. */
+      // Free the variable.  Don't remove it from the hashtab,
+      // ht_array might change then.  hash_clear() takes care of it
+      // later.
       v = HI2DI(hi);
-      if (free_val)
+      if (free_val) {
         clear_tv(&v->di_tv);
-      if ((v->di_flags & DI_FLAGS_FIX) == 0)
+      }
+      if (v->di_flags & DI_FLAGS_ALLOC) {
         xfree(v);
+      }
     }
   }
   hash_clear(ht);
@@ -18829,7 +18868,7 @@ set_var (
       xfree(v);
       return;
     }
-    v->di_flags = 0;
+    v->di_flags = DI_FLAGS_ALLOC;
   }
 
   if (copy || tv->v_type == VAR_NUMBER || tv->v_type == VAR_FLOAT) {
@@ -20720,7 +20759,7 @@ call_user_func (
       v->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
     } else {
       v = xmalloc(sizeof(dictitem_T) + STRLEN(name));
-      v->di_flags = DI_FLAGS_RO;
+      v->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX | DI_FLAGS_ALLOC;
     }
     STRCPY(v->di_key, name);
     hash_add(&fc->l_avars.dv_hashtab, DI2HIKEY(v));