Merge branch 'nox/fix-OTP-11506' into maint

* nox/fix-OTP-11506:
  Smoke test erl_syntax:revert/1
  Fix reverting of local implicit funs in erl_syntax

2 files changed, 34 insertions, 3 deletions

diff --git a/lib/syntax_tools/src/erl_syntax.erl b/lib/syntax_tools/src/erl_syntax.erl
index 409805e95f..775b2cc109 100644
--- a/lib/syntax_tools/src/erl_syntax.erl
+++ b/lib/syntax_tools/src/erl_syntax.erl
@@ -5485,7 +5485,13 @@ revert_implicit_fun(Node) ->
 	arity_qualifier ->
 	    F = arity_qualifier_body(Name),
 	    A = arity_qualifier_argument(Name),
-	    {'fun', Pos, {function, F, A}};
+	    case {type(F), type(A)} of
+		{atom, integer} ->
+		    {'fun', Pos,
+		     {function, concrete(F), concrete(A)}};
+		_ ->
+		    Node
+	    end;
 	module_qualifier ->
 	    M = module_qualifier_argument(Name),
 	    Name1 = module_qualifier_body(Name),
diff --git a/lib/syntax_tools/test/syntax_tools_SUITE.erl b/lib/syntax_tools/test/syntax_tools_SUITE.erl
index fd381f0b25..9eef56bddb 100644
--- a/lib/syntax_tools/test/syntax_tools_SUITE.erl
+++ b/lib/syntax_tools/test/syntax_tools_SUITE.erl
@@ -24,12 +24,12 @@
 	 init_per_group/2,end_per_group/2]).
 
 %% Test cases
--export([smoke_test/1]).
+-export([smoke_test/1,revert/1]).
 
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
 all() -> 
-    [smoke_test].
+    [smoke_test,revert].
 
 groups() -> 
     [].
@@ -79,6 +79,31 @@ print_error_markers(F, File) ->
     end.
     
 
+%% Read with erl_parse, wrap and revert with erl_syntax and check for equality.
+revert(Config) when is_list(Config) ->
+    Dog = ?t:timetrap(?t:minutes(12)),
+    Wc = filename:join([code:lib_dir("stdlib"),"src","*.erl"]),
+    Fs = filelib:wildcard(Wc),
+    Path = [filename:join(code:lib_dir(stdlib), "include"),
+            filename:join(code:lib_dir(kernel), "include")],
+    io:format("~p files\n", [length(Fs)]),
+    case p_run(fun (File) -> revert_file(File, Path) end, Fs) of
+        0 -> ok;
+        N -> ?line ?t:fail({N,errors})
+        end,
+    ?line ?t:timetrap_cancel(Dog).
+
+revert_file(File, Path) ->
+    case epp:parse_file(File, Path, []) of
+        {ok,Fs0} ->
+            Fs1 = erl_syntax:form_list(Fs0),
+            Fs2 = erl_syntax_lib:map(fun (Node) -> Node end, Fs1),
+            Fs3 = erl_syntax:form_list_elements(Fs2),
+            Fs4 = [ erl_syntax:revert(Form) || Form <- Fs3 ],
+            {ok,_} = compile:forms(Fs4, [report,strong_validation]),
+            ok
+    end.
+
 p_run(Test, List) ->
     N = erlang:system_info(schedulers),
     p_run_loop(Test, List, N, [], 0).