Fix evaluation of empty map updates in the debugger

4 files changed, 23 insertions, 11 deletions

diff --git a/lib/debugger/src/dbg_ieval.erl b/lib/debugger/src/dbg_ieval.erl
index 1d36aae8ee..0653ce4c00 100644
--- a/lib/debugger/src/dbg_ieval.erl
+++ b/lib/debugger/src/dbg_ieval.erl
@@ -663,12 +663,16 @@ expr({map,Line,Fs0}, Bs0, Ieval) ->
 expr({map,Line,E0,Fs0}, Bs0, Ieval0) ->
     Ieval = Ieval0#ieval{line=Line,top=false},
     {value,E,Bs1} = expr(E0, Bs0, Ieval),
-    {Fs,Bs2} = eval_map_fields(Fs0, Bs1, Ieval),
-    Value = lists:foldl(fun ({map_assoc,K,V}, Mi) -> maps:put(K,V,Mi);
-                            ({map_exact,K,V}, Mi) -> maps:update(K,V,Mi) end,
-                        E, Fs),
-    {value,Value,Bs2};
-
+    case E of
+        #{} ->
+            {Fs,Bs2} = eval_map_fields(Fs0, Bs1, Ieval),
+            Value = lists:foldl(fun ({map_assoc,K,V}, Mi) -> maps:put(K,V,Mi);
+                                    ({map_exact,K,V}, Mi) -> maps:update(K,V,Mi)
+                                end, E, Fs),
+            {value,Value,Bs2};
+        _ ->
+            exception(error, {badarg,E}, Bs1, Ieval)
+    end;
 %% A block of statements
 expr({block,Line,Es},Bs,Ieval) ->
     seq(Es, Bs, Ieval#ieval{line=Line});
diff --git a/lib/debugger/test/int_eval_SUITE.erl b/lib/debugger/test/int_eval_SUITE.erl
index 4ffcf7888e..ecbd68ab40 100644
--- a/lib/debugger/test/int_eval_SUITE.erl
+++ b/lib/debugger/test/int_eval_SUITE.erl
@@ -28,7 +28,7 @@
 	 bifs_outside_erlang/1, spawning/1, applying/1,
 	 catch_and_throw/1, external_call/1, test_module_info/1,
 	 apply_interpreted_fun/1, apply_uninterpreted_fun/1,
-	 interpreted_exit/1, otp_8310/1, stacktrace/1]).
+	 interpreted_exit/1, otp_8310/1, stacktrace/1, maps/1]).
 
 %% Helpers.
 -export([applier/3]).
@@ -44,7 +44,7 @@ all() ->
     [bifs_outside_erlang, spawning, applying,
      catch_and_throw, external_call, test_module_info,
      apply_interpreted_fun, apply_uninterpreted_fun,
-     interpreted_exit, otp_8310, stacktrace].
+     interpreted_exit, otp_8310, stacktrace, maps].
 
 groups() -> 
     [].
@@ -291,6 +291,11 @@ stacktrace(Config) when is_list(Config) ->
 	end,
     ok.
 
+maps(Config) when is_list(Config) ->
+    Fun = fun () -> ?IM:empty_map_update([camembert]) end,
+    {'EXIT',{{badarg,[camembert]},_}} = spawn_eval(Fun),
+    ok.
+
 
 do_eval(Config, Mod) ->
     ?line DataDir = ?config(data_dir, Config),
diff --git a/lib/debugger/test/int_eval_SUITE_data/my_int_eval_module.erl b/lib/debugger/test/int_eval_SUITE_data/my_int_eval_module.erl
index ab485fd350..e047a33d8c 100644
--- a/lib/debugger/test/int_eval_SUITE_data/my_int_eval_module.erl
+++ b/lib/debugger/test/int_eval_SUITE_data/my_int_eval_module.erl
@@ -29,6 +29,7 @@
 -export([more_catch/1,more_nocatch/1,exit_me/0]).
 -export([f/1, f_try/1, f_catch/1]).
 -export([otp_5837/1, otp_8310/0]).
+-export([empty_map_update/1]).
 
 %% Internal exports.
 -export([echo/2,my_subtract/2,catch_a_ball/0,throw_a_ball/0]).
@@ -241,3 +242,5 @@ otp_8310() ->
     true = begin (X3 = true) orelse X3, X3 end,
     false = begin (X4 = false) orelse X4, X4 end,
     ok.
+
+empty_map_update(Map) -> Map#{}.
diff --git a/lib/debugger/test/map_SUITE.erl b/lib/debugger/test/map_SUITE.erl
index e9f4ea1fad..fd07e7e40c 100644
--- a/lib/debugger/test/map_SUITE.erl
+++ b/lib/debugger/test/map_SUITE.erl
@@ -226,8 +226,8 @@ t_update_map_expressions(Config) when is_list(Config) ->
     #{ "a" :=1, "b":=42, "c":=42 } = (maps:from_list([{"a",1},{"b",2}]))#{ "b" := 42, "c" => 42 },
 
     %% Error cases, FIXME: should be 'badmap'?
-    {'EXIT',{badarg,_}} = (catch (id(<<>>))#{ a := 42, b => 2 }),
-    {'EXIT',{badarg,_}} = (catch (id([]))#{ a := 42, b => 2 }),
+    {'EXIT',{{badarg,<<>>},_}} = (catch (id(<<>>))#{ a := 42, b => 2 }),
+    {'EXIT',{{badarg,[]},_}} = (catch (id([]))#{ a := 42, b => 2 }),
     ok.
 
 
@@ -244,7 +244,7 @@ t_update_assoc(Config) when is_list(Config) ->
 
     %% Errors cases.
     BadMap = id(badmap),
-    {'EXIT',{badarg,_}} = (catch BadMap#{nonexisting=>val}),
+    {'EXIT',{{badarg,BadMap},_}} = (catch BadMap#{nonexisting=>val}),
 
     ok.