Properly parse quoted identifiers in function calls

lib/elixir/src/elixir_interpolation.erl

@@ -90,7 +90,10 @@ extract_char(Rest, Buffer, Output, Line, Column, Scope, Interpol, Last) ->
       Pos = io_lib:format(". If you want to use such character, use it in its escaped ~ts form instead", [Token]),
       {error, {?LOC(Line, Column), {Pre, Pos}, Token}};
 
-    [Char | NewRest] ->
+    [Char | NewRest] when is_list(Char) ->
+      extract(NewRest, lists:reverse(Char, Buffer), Output, Line, Column + 1, Scope, Interpol, Last);
+
+    [Char | NewRest] when is_integer(Char) ->
       extract(NewRest, [Char | Buffer], Output, Line, Column + 1, Scope, Interpol, Last);
 
     [] ->

lib/elixir/test/elixir/kernel/parser_test.exs

@@ -126,6 +126,10 @@ defmodule Kernel.ParserTest do
       # that are Common-script and non-ASCII
       # assert Code.eval_string("_ℕ𝕩 = 1") == {1, [{:"_ℕ𝕩", 1}]}
     end
+
+    test "handles graphemes inside quoted identifiers" do
+      assert {{:., _, [{:foo, _, nil}, :"➡️"]}, _, []} = Code.string_to_quoted!(~s|foo."➡️"|)
+    end
   end
 
   describe "strings/sigils" do

lib/iex/test/iex/interaction_test.exs

@@ -93,7 +93,8 @@ defmodule IEx.InteractionTest do
     output = capture_iex(input)
 
     assert output =~ "** (TokenMissingError) token missing on iex:1:"
-    assert output =~ "error: incomplete expression\n"
+    assert output =~ "error:"
+    assert output =~ "incomplete expression\n"
     assert output =~ "iex:1"
   end