fix(vim.opt): #14708 Now lets you put duplicate values in wildmode

runtime/lua/vim/_meta.lua

@@ -325,9 +325,12 @@ local convert_value_to_vim = (function()
       return result
     end,
 
-    [OptionTypes.ARRAY] = function(_, value)
+    [OptionTypes.ARRAY] = function(info, value)
       if type(value) == "string" then return value end
-      return table.concat(remove_duplicate_values(value), ",")
+      if not info.allows_duplicates then
+        value = remove_duplicate_values(value)
+      end
+      return table.concat(value, ",")
     end,
 
     [OptionTypes.MAP] = function(_, value)

src/nvim/option.c

@@ -7765,6 +7765,7 @@ static Dictionary vimoption2dict(vimoption_T *opt)
     }
     PUT(dict, "type", CSTR_TO_OBJ(type));
     PUT(dict, "default", def);
+    PUT(dict, "allows_duplicates", BOOL(!(opt->flags & P_NODUP)));
 
     return dict;
 }

src/nvim/options.lua

@@ -3152,7 +3152,7 @@ return {
       full_name='wildmode', abbreviation='wim',
       short_desc=N_("mode for 'wildchar' command-line expansion"),
       type='string', list='onecomma', scope={'global'},
-      deny_duplicates=true,
+      deny_duplicates=false,
       vim=true,
       varname='p_wim',
       defaults={if_true={vi="", vim="full"}}

test/functional/lua/vim_spec.lua

@@ -1569,7 +1569,15 @@ describe('lua stdlib', function()
       eq(wildignore, 'super_first,first,foo')
     end)
 
-  end)
+    it('should not remove duplicates from wildmode: #14708', function()
+      local wildmode = exec_lua [[
+        vim.opt.wildmode = {"full", "list", "full"}
+        return vim.o.wildmode
+      ]]
+
+      eq(wildmode, 'full,list,full')
+    end)
+  end) -- vim.opt
 
   it('vim.cmd', function()
     exec_lua [[