Merge branch 'sverk/maps-erl_interface'

* sverk/maps-erl_interface:
  erts: Add distribution capability flag for maps DFLAG_MAP_TAG
  erts: Change external format for maps
  erts: Document external format for maps (MAP_EXT)
  erl_interface: Add test for ei_skip_term of container terms
  erl_interface: Add map support in ei_skip_term
  erl_interface: Fix mem leak in ei_decode_encode_test
  erl_interface: test decode/encode of maps
  erl_interface: Add ei encode/decode for maps
  erl_interface: test decode_encode of tuples and lists
  erl_interface: refactor ei_decode_encode_test.c

19 files changed, 490 insertions, 169 deletions

diff --git a/lib/debugger/test/map_SUITE.erl b/lib/debugger/test/map_SUITE.erl
index e9f4ea1fad..741ad2dc41 100644
--- a/lib/debugger/test/map_SUITE.erl
+++ b/lib/debugger/test/map_SUITE.erl
@@ -790,16 +790,16 @@ t_map_encode_decode(Config) when is_list(Config) ->
 
     %% literally #{ b=>2, a=>1 } in the internal order
     #{ a:=1, b:=2 } =
-	erlang:binary_to_term(<<131,116,0,0,0,2,100,0,1,98,100,0,1,97,97,2,97,1>>),
+	erlang:binary_to_term(<<131,116,0,0,0,2,100,0,1,98,97,2,100,0,1,97,97,1>>),
 
 
     %% literally #{ "hi" => "value", a=>33, b=>55 } in the internal order
     #{ a:=33, b:=55, "hi" := "value"} = erlang:binary_to_term(<<131,116,0,0,0,3,
 	107,0,2,104,105, % "hi" :: list()
-	100,0,1,97, % a :: atom()
-	100,0,1,98, % b :: atom()
 	107,0,5,118,97,108,117,101, % "value" :: list()
+	100,0,1,97, % a :: atom()
 	97,33, % 33 :: integer()
+	100,0,1,98, % b :: atom()
 	97,55  % 55 :: integer()
 	>>),
 
@@ -829,7 +829,8 @@ map_encode_decode_and_match([{K,V}|Pairs], EncodedPairs, M0) ->
     B0 = erlang:term_to_binary(M1),
     Ls = lists:sort(fun(A,B) -> erts_internal:cmp_term(A,B) < 0 end, [{K, erlang:term_to_binary(K), erlang:term_to_binary(V)}|EncodedPairs]),
     %% sort Ks and Vs according to term spec, then match it
-    ok = match_encoded_map(B0, length(Ls), [Kbin||{_,Kbin,_}<-Ls] ++ [Vbin||{_,_,Vbin}<-Ls]),
+    KVbins = lists:foldr(fun({_,Kbin,Vbin}, Acc) -> [Kbin,Vbin | Acc] end, [], Ls),
+    ok = match_encoded_map(B0, length(Ls), KVbins),
     %% decode and match it
     M1 = erlang:binary_to_term(B0),
     map_encode_decode_and_match(Pairs,Ls,M1);
diff --git a/lib/erl_interface/doc/src/ei.xml b/lib/erl_interface/doc/src/ei.xml
index ab185c9179..90495eebd6 100644
--- a/lib/erl_interface/doc/src/ei.xml
+++ b/lib/erl_interface/doc/src/ei.xml
@@ -4,7 +4,7 @@
 <cref>
   <header>
     <copyright>
-      <year>2001</year><year>2013</year>
+      <year>2001</year><year>2014</year>
       <holder>Ericsson AB. All Rights Reserved.</holder>
     </copyright>
     <legalnotice>
@@ -417,6 +417,26 @@ ei_x_encode_empty_list(&amp;x);
       </desc>
     </func>
     <func>
+      <name><ret>int</ret><nametext>ei_encode_map_header(char *buf, int *index, int arity)</nametext></name>
+      <name><ret>int</ret><nametext>ei_x_encode_map_header(ei_x_buff* x, int arity)</nametext></name>
+      <fsummary>Encode a map</fsummary>
+      <desc>
+        <p>This function encodes a map header, with a specified arity. The next
+	   <c>arity*2</c> terms encoded will be the keys and values of the map
+	   encoded in the following order: <c>K1, V1, K2, V2, ..., Kn, Vn</c>.
+	</p>
+        <p>E.g. to encode the map <c>#{a => "Apple", b => "Banana"}</c>:</p>
+        <pre>
+ei_x_encode_map_header(&amp;x, 2);
+ei_x_encode_atom(&amp;x, "a");
+ei_x_encode_string(&amp;x, "Apple");
+ei_x_encode_atom(&amp;x, "b");
+ei_x_encode_string(&amp;x, "Banana");
+        </pre>
+	<p>A correctly encoded map can not have duplicate keys.</p>
+      </desc>
+    </func>
+    <func>
       <name><ret>int</ret><nametext>ei_get_type(const char *buf, const int *index, int *type, int *size)</nametext></name>
       <fsummary>Fetch the type and size of an encoded term</fsummary>
       <desc>
@@ -638,6 +658,18 @@ ei_x_encode_empty_list(&amp;x);
       </desc>
     </func>
     <func>
+      <name><ret>int</ret><nametext>ei_decode_map_header(const char *buf, int *index, int *arity)</nametext></name>
+      <fsummary>Decode a map</fsummary>
+      <desc>
+        <p>This function decodes a map header from the binary
+          format. The number of key-value pairs is returned in
+          <c>*arity</c>. Keys and values follow in the following order:
+	  <c>K1, V1, K2, V2, ..., Kn, Vn</c>. This makes a total of
+	  <c>arity*2</c> terms. If <c>arity</c> is zero, it's an empty map.
+	  A correctly encoded map does not have duplicate keys.</p>
+      </desc>
+    </func>
+    <func>
       <name><ret>int</ret><nametext>ei_decode_ei_term(const char* buf, int* index, ei_term* term)</nametext></name>
       <fsummary>Decode a term, without prior knowledge of type</fsummary>
       <desc>
diff --git a/lib/erl_interface/include/ei.h b/lib/erl_interface/include/ei.h
index 9b83385a46..a3eb437f88 100644
--- a/lib/erl_interface/include/ei.h
+++ b/lib/erl_interface/include/ei.h
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  *
- * Copyright Ericsson AB 1998-2013. All Rights Reserved.
+ * Copyright Ericsson AB 1998-2014. All Rights Reserved.
  *
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -131,6 +131,7 @@
 #define ERL_SMALL_BIG_EXT     'n'
 #define ERL_LARGE_BIG_EXT     'o'
 #define ERL_NEW_FUN_EXT	      'p'
+#define ERL_MAP_EXT           't'
 #define ERL_FUN_EXT	      'u'
  
 #define ERL_NEW_CACHE         'N' /* c nodes don't know these two */
@@ -467,6 +468,8 @@ int ei_encode_list_header(char *buf, int *index, int arity);
 int ei_x_encode_list_header(ei_x_buff* x, long n);
 #define ei_encode_empty_list(buf,i) ei_encode_list_header(buf,i,0)
 int ei_x_encode_empty_list(ei_x_buff* x);
+int ei_encode_map_header(char *buf, int *index, int arity);
+int ei_x_encode_map_header(ei_x_buff* x, long n);
 
 /* 
  * ei_get_type() returns the type and "size" of the item at
@@ -507,6 +510,7 @@ int ei_decode_term(const char *buf, int *index, void *t); /* ETERM** actually */
 int ei_decode_trace(const char *buf, int *index, erlang_trace *p);
 int ei_decode_tuple_header(const char *buf, int *index, int *arity);
 int ei_decode_list_header(const char *buf, int *index, int *arity);
+int ei_decode_map_header(const char *buf, int *index, int *arity);
 
 /* 
  * ei_decode_ei_term() returns 1 if term is decoded, 0 if term is OK,
diff --git a/lib/erl_interface/src/connect/ei_connect.c b/lib/erl_interface/src/connect/ei_connect.c
index c9aa28812c..3175d1bdfd 100644
--- a/lib/erl_interface/src/connect/ei_connect.c
+++ b/lib/erl_interface/src/connect/ei_connect.c
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  *
- * Copyright Ericsson AB 2000-2013. All Rights Reserved.
+ * Copyright Ericsson AB 2000-2014. All Rights Reserved.
  *
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -1336,7 +1336,8 @@ static int send_name_or_challenge(int fd, char *nodename,
 		| DFLAG_NEW_FUN_TAGS
                 | DFLAG_NEW_FLOATS
 		| DFLAG_SMALL_ATOM_TAGS
-		| DFLAG_UTF8_ATOMS));
+		| DFLAG_UTF8_ATOMS
+		| DFLAG_MAP_TAG));
     if (f_chall)
 	put32be(s, challenge);
     memcpy(s, nodename, strlen(nodename));
diff --git a/lib/erl_interface/src/connect/ei_connect_int.h b/lib/erl_interface/src/connect/ei_connect_int.h
index 42ab9b58d7..8fab47a787 100644
--- a/lib/erl_interface/src/connect/ei_connect_int.h
+++ b/lib/erl_interface/src/connect/ei_connect_int.h
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  *
- * Copyright Ericsson AB 2001-2013. All Rights Reserved.
+ * Copyright Ericsson AB 2001-2014. All Rights Reserved.
  *
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -104,6 +104,7 @@ extern int h_errno;
 #define DFLAG_NEW_FLOATS          0x800
 #define DFLAG_SMALL_ATOM_TAGS     0x4000
 #define DFLAG_UTF8_ATOMS          0x10000
+#define DFLAG_MAP_TAG             0x20000
 
 ei_cnode   *ei_fd_to_cnode(int fd);
 int         ei_distversion(int fd);
diff --git a/lib/erl_interface/src/decode/decode_skip.c b/lib/erl_interface/src/decode/decode_skip.c
index 553266471c..2260394da1 100644
--- a/lib/erl_interface/src/decode/decode_skip.c
+++ b/lib/erl_interface/src/decode/decode_skip.c
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  *
- * Copyright Ericsson AB 2002-2013. All Rights Reserved.
+ * Copyright Ericsson AB 2002-2014. All Rights Reserved.
  *
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -61,7 +61,13 @@ int ei_skip_term(const char* buf, int* index)
 	break;
     case ERL_SMALL_TUPLE_EXT:
     case ERL_LARGE_TUPLE_EXT:
-	if (ei_decode_tuple_header(buf, index, &n) < 0) return -1;	
+	if (ei_decode_tuple_header(buf, index, &n) < 0) return -1;
+	for (i = 0; i < n; ++i)
+	    ei_skip_term(buf, index);
+	break;
+    case ERL_MAP_EXT:
+	if (ei_decode_map_header(buf, index, &n) < 0) return -1;
+	n *= 2;
 	for (i = 0; i < n; ++i)
 	    ei_skip_term(buf, index);
 	break;
diff --git a/lib/erl_interface/src/decode/decode_tuple_header.c b/lib/erl_interface/src/decode/decode_tuple_header.c
index c0ba14ea47..698be1b97a 100644
--- a/lib/erl_interface/src/decode/decode_tuple_header.c
+++ b/lib/erl_interface/src/decode/decode_tuple_header.c
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  * 
- * Copyright Ericsson AB 1998-2009. All Rights Reserved.
+ * Copyright Ericsson AB 1998-2014. All Rights Reserved.
  * 
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -45,3 +45,24 @@ int ei_decode_tuple_header(const char *buf, int *index, int *arity)
 
   return 0;
 }
+
+int ei_decode_map_header(const char *buf, int *index, int *arity)
+{
+  const char *s = buf + *index;
+  const char *s0 = s;
+  int i;
+
+  switch ((i=get8(s))) {
+  case ERL_MAP_EXT:
+    if (arity) *arity = get32be(s);
+    else s += 4;
+    break;
+
+  default:
+    return -1;
+  }
+
+  *index += s-s0;
+
+  return 0;
+}
diff --git a/lib/erl_interface/src/encode/encode_tuple_header.c b/lib/erl_interface/src/encode/encode_tuple_header.c
index 97a3d1f808..5b11e60447 100644
--- a/lib/erl_interface/src/encode/encode_tuple_header.c
+++ b/lib/erl_interface/src/encode/encode_tuple_header.c
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  * 
- * Copyright Ericsson AB 1998-2009. All Rights Reserved.
+ * Copyright Ericsson AB 1998-2014. All Rights Reserved.
  * 
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -47,3 +47,20 @@ int ei_encode_tuple_header(char *buf, int *index, int arity)
   return 0;
 }
 
+int ei_encode_map_header(char *buf, int *index, int arity)
+{
+  char *s = buf + *index;
+  char *s0 = s;
+
+  if (arity < 0) return -1;
+
+  if (!buf) s += 5;
+  else {
+      put8(s,ERL_MAP_EXT);
+      put32be(s,arity);
+  }
+
+  *index += s-s0;
+
+  return 0;
+}
diff --git a/lib/erl_interface/src/misc/ei_decode_term.c b/lib/erl_interface/src/misc/ei_decode_term.c
index ce5ae5b19d..2e7317f781 100644
--- a/lib/erl_interface/src/misc/ei_decode_term.c
+++ b/lib/erl_interface/src/misc/ei_decode_term.c
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  *
- * Copyright Ericsson AB 2001-2013. All Rights Reserved.
+ * Copyright Ericsson AB 2001-2014. All Rights Reserved.
  *
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -100,6 +100,7 @@ int ei_decode_ei_term(const char* buf, int* index, ei_term* term)
 	term->size = get16be(s);
 	return 0;
     case ERL_LIST_EXT:
+    case ERL_MAP_EXT:
 	term->arity = get32be(s);
 	break;
     case ERL_BINARY_EXT:
diff --git a/lib/erl_interface/src/misc/ei_x_encode.c b/lib/erl_interface/src/misc/ei_x_encode.c
index 14d0b56b8f..10542c88a5 100644
--- a/lib/erl_interface/src/misc/ei_x_encode.c
+++ b/lib/erl_interface/src/misc/ei_x_encode.c
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  * 
- * Copyright Ericsson AB 2001-2013. All Rights Reserved.
+ * Copyright Ericsson AB 2001-2014. All Rights Reserved.
  * 
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -206,6 +206,16 @@ int ei_x_encode_tuple_header(ei_x_buff* x, long n)
     return ei_encode_tuple_header(x->buff, &x->index, n);
 }
 
+int ei_x_encode_map_header(ei_x_buff* x, long n)
+{
+    int i = x->index;
+    if (ei_encode_map_header(NULL, &i, n) == -1)
+      return -1;
+    if (!x_fix_buff(x, i))
+	return -1;
+    return ei_encode_map_header(x->buff, &x->index, n);
+}
+
 int ei_x_encode_atom(ei_x_buff* x, const char* s)
 {
     return ei_x_encode_atom_len_as(x, s, strlen(s), ERLANG_LATIN1, ERLANG_LATIN1);
diff --git a/lib/erl_interface/test/all_SUITE_data/ei_runner.c b/lib/erl_interface/test/all_SUITE_data/ei_runner.c
index cdf32b48c4..196a77dce5 100644
--- a/lib/erl_interface/test/all_SUITE_data/ei_runner.c
+++ b/lib/erl_interface/test/all_SUITE_data/ei_runner.c
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  * 
- * Copyright Ericsson AB 2001-2009. All Rights Reserved.
+ * Copyright Ericsson AB 2001-2014. All Rights Reserved.
  * 
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -182,6 +182,10 @@ char *read_packet(int *len)
     return io_buf;
 }
 
+void free_packet(char* packet)
+{
+    free(packet);
+}
 
 /***********************************************************************
  * S e n d i n g   r e p l i e s
diff --git a/lib/erl_interface/test/all_SUITE_data/ei_runner.h b/lib/erl_interface/test/all_SUITE_data/ei_runner.h
index 96d6a1cbf7..a037341d57 100644
--- a/lib/erl_interface/test/all_SUITE_data/ei_runner.h
+++ b/lib/erl_interface/test/all_SUITE_data/ei_runner.h
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  * 
- * Copyright Ericsson AB 2001-2009. All Rights Reserved.
+ * Copyright Ericsson AB 2001-2014. All Rights Reserved.
  * 
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -44,6 +44,7 @@ void run_tests(char* argv0, TestCase cases[], unsigned number);
 
 int get_bin_term(ei_x_buff* x, ei_term* term);
 char *read_packet(int *len);
+void free_packet(char*);
 
 /*
  * Sending replies.
diff --git a/lib/erl_interface/test/ei_decode_encode_SUITE.erl b/lib/erl_interface/test/ei_decode_encode_SUITE.erl
index c7830f58f2..7caec6ac04 100644
--- a/lib/erl_interface/test/ei_decode_encode_SUITE.erl
+++ b/lib/erl_interface/test/ei_decode_encode_SUITE.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2004-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2004-2014. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -127,6 +127,15 @@ test_ei_decode_encode(Config) when is_list(Config) ->
 	   send_rec(P, mk_ref({Atom,1}, [262143, 8723648, 24097245])),
 	   void
      end || Atom <- unicode_atom_data()],
+
+    send_rec(P, {}),
+    send_rec(P, {atom, Pid, Port, Ref}),
+    send_rec(P, [atom, Pid, Port, Ref]),
+    send_rec(P, [atom | Fun]),
+    send_rec(P, #{}),
+    send_rec(P, #{key => value}),
+    send_rec(P, maps:put(Port, Ref, #{key => value, key2 => Pid})),
+
     ?line runner:recv_eot(P),
     ok.
 
diff --git a/lib/erl_interface/test/ei_decode_encode_SUITE_data/ei_decode_encode_test.c b/lib/erl_interface/test/ei_decode_encode_SUITE_data/ei_decode_encode_test.c
index 317e5edecd..fcf546105b 100644
--- a/lib/erl_interface/test/ei_decode_encode_SUITE_data/ei_decode_encode_test.c
+++ b/lib/erl_interface/test/ei_decode_encode_SUITE_data/ei_decode_encode_test.c
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  * 
- * Copyright Ericsson AB 2004-2013. All Rights Reserved.
+ * Copyright Ericsson AB 2004-2014. All Rights Reserved.
  * 
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -32,9 +32,33 @@
 /*#define MESSAGE(FMT,A1,A2) message(FMT,A1,A2)*/
 #define MESSAGE(FMT,A1,A2)
 
-typedef int decodeFT(const char *buf, int *index, void*);
-typedef int encodeFT(char *buf, int *index, void*);
-typedef int x_encodeFT(ei_x_buff*, void*);
+
+typedef struct
+{
+    char name[MAXATOMLEN_UTF8];
+    erlang_char_encoding enc;
+}my_atom;
+
+struct my_obj {
+    union {
+	erlang_fun fun;
+	erlang_pid pid;
+	erlang_port port;
+	erlang_ref ref;
+	erlang_trace trace;
+	erlang_big big;
+	my_atom atom;
+
+	int arity;
+    }u;
+
+    int nterms; /* 0 for non-containers */
+    char* startp; /* container start position in decode buffer */
+};
+
+typedef int decodeFT(const char *buf, int *index, struct my_obj*);
+typedef int encodeFT(char *buf, int *index, struct my_obj*);
+typedef int x_encodeFT(ei_x_buff*, struct my_obj*);
 
 struct Type {
     char* name;
@@ -44,11 +68,36 @@ struct Type {
     x_encodeFT* ei_x_encode_fp;
 };
 
-typedef struct
-{
-    char name[MAXATOMLEN_UTF8];
-    erlang_char_encoding enc;
-}my_atom;
+
+struct Type fun_type = {
+    "fun", "erlang_fun", (decodeFT*)ei_decode_fun,
+    (encodeFT*)ei_encode_fun, (x_encodeFT*)ei_x_encode_fun
+};
+
+struct Type pid_type = {
+    "pid", "erlang_pid", (decodeFT*)ei_decode_pid,
+    (encodeFT*)ei_encode_pid, (x_encodeFT*)ei_x_encode_pid
+};
+
+struct Type port_type = {
+    "port", "erlang_port", (decodeFT*)ei_decode_port,
+    (encodeFT*)ei_encode_port, (x_encodeFT*)ei_x_encode_port
+};
+
+struct Type ref_type = {
+    "ref", "erlang_ref", (decodeFT*)ei_decode_ref,
+    (encodeFT*)ei_encode_ref, (x_encodeFT*)ei_x_encode_ref
+};
+
+struct Type trace_type = {
+    "trace", "erlang_trace", (decodeFT*)ei_decode_trace,
+    (encodeFT*)ei_encode_trace, (x_encodeFT*)ei_x_encode_trace
+};
+
+struct Type big_type = {
+    "big", "erlang_big", (decodeFT*)ei_decode_big,
+    (encodeFT*)ei_encode_big, (x_encodeFT*)ei_x_encode_big
+};
 
 int ei_decode_my_atom(const char *buf, int *index, my_atom* a)
 {
@@ -64,130 +113,274 @@ int ei_x_encode_my_atom(ei_x_buff* x, my_atom* a)
     return ei_x_encode_atom_as(x, a->name, ERLANG_UTF8, a->enc);
 }
 
+struct Type my_atom_type = {
+    "atom", "my_atom", (decodeFT*)ei_decode_my_atom,
+    (encodeFT*)ei_encode_my_atom, (x_encodeFT*)ei_x_encode_my_atom
+};
+
+
+int my_decode_tuple_header(const char *buf, int *index, struct my_obj* obj)
+{
+    int ret = ei_decode_tuple_header(buf, index, &obj->u.arity);
+    if (ret == 0 && obj)
+	obj->nterms = obj->u.arity;
+    return ret;
+}
+
+int my_encode_tuple_header(char *buf, int *index, struct my_obj* obj)
+{
+    return ei_encode_tuple_header(buf, index, obj->u.arity);
+}
+int my_x_encode_tuple_header(ei_x_buff* x, struct my_obj* obj)
+{
+    return ei_x_encode_tuple_header(x, (long)obj->u.arity);
+}
+
+struct Type tuple_type = {
+    "tuple_header", "arity", my_decode_tuple_header,
+    my_encode_tuple_header, my_x_encode_tuple_header
+};
+
+
+int my_decode_list_header(const char *buf, int *index, struct my_obj* obj)
+{
+    int ret = ei_decode_list_header(buf, index, &obj->u.arity);
+    if (ret == 0 && obj) {
+	obj->nterms = obj->u.arity + 1;
+    }
+    return ret;
+}
+int my_encode_list_header(char *buf, int *index, struct my_obj* obj)
+{
+    return ei_encode_list_header(buf, index, obj->u.arity);
+}
+int my_x_encode_list_header(ei_x_buff* x, struct my_obj* obj)
+{
+    return ei_x_encode_list_header(x, (long)obj->u.arity);
+}
+
+struct Type list_type = {
+    "list_header", "arity", my_decode_list_header,
+    my_encode_list_header, my_x_encode_list_header
+};
+
+
+int my_decode_nil(const char *buf, int *index, struct my_obj* dummy)
+{
+    int type, size, ret;
+    ret = ei_get_type(buf, index, &type, &size);
+    (*index)++;
+    return ret ?  ret : !(type == ERL_NIL_EXT);
+
+}
+int my_encode_nil(char *buf, int *index, struct my_obj* dummy)
+{
+    return ei_encode_empty_list(buf, index);
+}
+
+int my_x_encode_nil(ei_x_buff* x, struct my_obj* dummy)
+{
+    return ei_x_encode_empty_list(x);
+}
+
+struct Type nil_type = {
+    "empty_list", "nil", my_decode_nil,
+    my_encode_nil, my_x_encode_nil
+};
+
+int my_decode_map_header(const char *buf, int *index, struct my_obj* obj)
+{
+    int ret = ei_decode_map_header(buf, index, &obj->u.arity);
+    if (ret == 0 && obj)
+	obj->nterms = obj->u.arity * 2;
+    return ret;
+}
+int my_encode_map_header(char *buf, int *index, struct my_obj* obj)
+{
+    return ei_encode_map_header(buf, index, obj->u.arity);
+}
+int my_x_encode_map_header(ei_x_buff* x, struct my_obj* obj)
+{
+    return ei_x_encode_map_header(x, (long)obj->u.arity);
+}
+
+struct Type map_type = {
+    "map_header", "arity", my_decode_map_header,
+    my_encode_map_header, my_x_encode_map_header
+};
+
+
 #define BUFSZ 2000
 
-void decode_encode(struct Type* t, void* obj)
+void decode_encode(struct Type** tv, int nobj)
 {
-    char *buf;
-    char buf2[BUFSZ];
-    int size1 = 0;
-    int size2 = 0;
-    int size3 = 0;
-    int err;
+    struct my_obj objv[10];
+    int oix = 0;
+    char* packet;
+    char* inp;
+    char* outp;
+    char out_buf[BUFSZ];
+    int size1, size2, size3;
+    int err, i;
     ei_x_buff arg;
     
-    MESSAGE("ei_decode_%s, arg is type %s", t->name, t->type);
-    buf = read_packet(NULL);
-    err = t->ei_decode_fp(buf+1, &size1, NULL);
-    if (err != 0) {
-	if (err != -1) {
-	    fail("decode returned non zero but not -1");
-	} else {
-	    fail("decode returned non zero");
+    packet = read_packet(NULL);
+    inp = packet+1;
+    outp = out_buf;
+    ei_x_new(&arg);
+    for (i=0; i<nobj; i++) {
+	struct Type* t = tv[i];
+
+	MESSAGE("ei_decode_%s, arg is type %s", t->name, t->type);
+
+	size1 = 0;
+	err = t->ei_decode_fp(inp, &size1, NULL);
+	if (err != 0) {
+	    if (err != -1) {
+		fail("decode returned non zero but not -1");
+	    } else {
+		fail("decode returned non zero");
+	    }
+	    return;
+	}
+	if (size1 < 1) {
+	    fail("size is < 1");
+	    return;
 	}
-	return;
-    }
-    if (size1 < 1) {
-	fail("size is < 1");
-	return;
-    }
 
-    if (size1 > BUFSZ) {
-	fail("size is > BUFSZ");
-	return;
-    }
+	if (size1 > BUFSZ) {
+	    fail("size is > BUFSZ");
+	    return;
+	}
 
-    err = t->ei_decode_fp(buf+1, &size2, obj);
-    if (err != 0) {
-	if (err != -1) {
-	    fail("decode returned non zero but not -1");
-	} else {
-	    fail("decode returned non zero");
+	size2 = 0;
+	objv[oix].nterms = 0;
+	objv[oix].startp = inp;
+	err = t->ei_decode_fp(inp, &size2, &objv[oix]);
+	if (err != 0) {
+	    if (err != -1) {
+		fail("decode returned non zero but not -1");
+	    } else {
+		fail("decode returned non zero");
+	    }
+	    return;
+	}
+	if (size1 != size2) {
+	    MESSAGE("size1 = %d, size2 = %d\n",size1,size2);
+	    fail("decode sizes differs");
+	    return;
 	}
-	return;
-    }
-    if (size1 != size2) {
-	MESSAGE("size1 = %d, size2 = %d\n",size1,size2);
-	fail("decode sizes differs");
-	return;
-    }
 
-    size2 = 0;
-    err = ei_skip_term(buf+1, &size2);
-    if (err != 0) {
-	fail("ei_skip_term returned non zero");
-	return;
-    }
-    if (size1 != size2) {
-	MESSAGE("size1 = %d, size2 = %d\n",size1,size2);
-	fail("skip size differs");
-	return;
-    }
+	if (!objv[oix].nterms) {
+	    size2 = 0;
+	    err = ei_skip_term(inp, &size2);
+	    if (err != 0) {
+		fail("ei_skip_term returned non zero");
+		return;
+	    }
+	    if (size1 != size2) {
+		MESSAGE("size1 = %d, size2 = %d\n",size1,size2);
+		fail("skip size differs");
+		return;
+	    }
+	}
 
-    MESSAGE("ei_encode_%s buf is NULL, arg is type %s", t->name, t->type);
-    size2 = 0;
-    err = t->ei_encode_fp(NULL, &size2, obj);
-    if (err != 0) {
-	if (err != -1) {
-	    fail("size calculation returned non zero but not -1");
+	MESSAGE("ei_encode_%s buf is NULL, arg is type %s", t->name, t->type);
+	size2 = 0;
+	err = t->ei_encode_fp(NULL, &size2, &objv[oix]);
+	if (err != 0) {
+	    if (err != -1) {
+		fail("size calculation returned non zero but not -1");
+		return;
+	    } else {
+		fail("size calculation returned non zero");
+		return;
+	    }
+	}
+	if (size1 != size2) {
+	    MESSAGE("size1 = %d, size2 = %d\n",size1,size2);
+	    fail("decode and encode size differs when buf is NULL");
 	    return;
-	} else {
-	    fail("size calculation returned non zero");
+	}
+	MESSAGE("ei_encode_%s, arg is type %s", t->name, t->type);
+	size3 = 0;
+	err = t->ei_encode_fp(outp, &size3, &objv[oix]);
+	if (err != 0) {
+	    if (err != -1) {
+		fail("returned non zero but not -1");
+	    } else {
+		fail("returned non zero");
+	    }
 	    return;
 	}
-    }
-    if (size1 != size2) {
-	MESSAGE("size1 = %d, size2 = %d\n",size1,size2);
-	fail("decode and encode size differs when buf is NULL");
-	return;
-    }
-    MESSAGE("ei_encode_%s, arg is type %s", t->name, t->type);
-    err = t->ei_encode_fp(buf2, &size3, obj);
-    if (err != 0) {
-	if (err != -1) {
-	    fail("returned non zero but not -1");
-	} else {
-	    fail("returned non zero");
+	if (size1 != size3) {
+	    MESSAGE("size1 = %d, size2 = %d\n",size1,size3);
+	    fail("decode and encode size differs");
+	    return;
 	}
-	return;
-    }
-    if (size1 != size3) {
-	MESSAGE("size1 = %d, size2 = %d\n",size1,size3);
-	fail("decode and encode size differs");
-	return;
-    }
-    send_buffer(buf2, size1);
 
-    MESSAGE("ei_x_encode_%s, arg is type %s", t->name, t->type);
-    ei_x_new(&arg);
-    err = t->ei_x_encode_fp(&arg, obj);
-    if (err != 0) {
-	if (err != -1) {
-	    fail("returned non zero but not -1");
-	} else {
-	    fail("returned non zero");
+	MESSAGE("ei_x_encode_%s, arg is type %s", t->name, t->type);
+	err = t->ei_x_encode_fp(&arg, &objv[oix]);
+	if (err != 0) {
+	    if (err != -1) {
+		fail("returned non zero but not -1");
+	    } else {
+		fail("returned non zero");
+	    }
+	    ei_x_free(&arg);
+	    return;
 	}
-	ei_x_free(&arg);
-	return;
+	if (arg.index < 1) {
+	    fail("size is < 1");
+	    ei_x_free(&arg);
+	    return;
+	}
+
+	inp += size1;
+	outp += size1;
+
+	if (objv[oix].nterms) { /* container term */
+	    if (++oix >= sizeof(objv)/sizeof(*objv))
+		fail("Term too deep");
+	}
+	else { /* "leaf" term */
+	    while (oix > 0) {
+		if (--(objv[oix - 1].nterms) == 0) {
+		    /* last element in container */
+		    --oix;
+
+		    size2 = 0;
+		    err = ei_skip_term(objv[oix].startp, &size2);
+		    if (err != 0) {
+			fail("ei_skip_term returned non zero");
+			return;
+		    }
+		    if (objv[oix].startp + size2 != inp) {
+			MESSAGE("size1 = %d, size2 = %d\n", size1, size2);
+			fail("container skip size differs");
+			return;
+		    }
+		}
+		else
+		    break; /* more elements in container */
+	    }
+	}
+
     }
-    if (arg.index < 1) {
-	fail("size is < 1");
-	ei_x_free(&arg);
-	return;
+    if (oix > 0) {
+	fail("Container not complete");
     }
+    send_buffer(out_buf, outp - out_buf);
     send_buffer(arg.buff, arg.index);
     ei_x_free(&arg);
+    free_packet(packet);
 }
 
+void decode_encode_one(struct Type* t)
+{
+    decode_encode(&t, 1);
+}
 
-#define EI_DECODE_ENCODE(TYPE, ERLANG_TYPE) {			\
-	struct Type type_struct = {#TYPE, #ERLANG_TYPE,		\
-				   (decodeFT*)ei_decode_##TYPE,		\
-				   (encodeFT*)ei_encode_##TYPE,		\
-				   (x_encodeFT*)ei_x_encode_##TYPE };	\
-	ERLANG_TYPE type_obj;						\
-	decode_encode(&type_struct, &type_obj);				\
-    }
 
 
 void decode_encode_big(struct Type* t)
@@ -274,14 +467,6 @@ void decode_encode_big(struct Type* t)
     ei_free_big(p);
 }
 
-#define EI_DECODE_ENCODE_BIG(TYPE, ERLANG_TYPE) {					\
-	struct Type type_struct = {#TYPE, #ERLANG_TYPE,		\
-				   (decodeFT*)ei_decode_##TYPE,	\
-				   (encodeFT*)ei_encode_##TYPE,		\
-				   (x_encodeFT*)ei_x_encode_##TYPE };	\
-	decode_encode_big(&type_struct);				\
-    }
-
 
 
 /* ******************************************************************** */
@@ -290,34 +475,63 @@ TESTCASE(test_ei_decode_encode)
 {
     int i;
 
-    EI_DECODE_ENCODE(fun  , erlang_fun);
-    EI_DECODE_ENCODE(pid  , erlang_pid);
-    EI_DECODE_ENCODE(port , erlang_port);
-    EI_DECODE_ENCODE(ref  , erlang_ref);
-    EI_DECODE_ENCODE(trace, erlang_trace);
+    decode_encode_one(&fun_type);
+    decode_encode_one(&pid_type);
+    decode_encode_one(&port_type);
+    decode_encode_one(&ref_type);
+    decode_encode_one(&trace_type);
 
-    EI_DECODE_ENCODE_BIG(big  , erlang_big);
-    EI_DECODE_ENCODE_BIG(big  , erlang_big);
-    EI_DECODE_ENCODE_BIG(big  , erlang_big);
+    decode_encode_big(&big_type);
+    decode_encode_big(&big_type);
+    decode_encode_big(&big_type);
 
-    EI_DECODE_ENCODE_BIG(big  , erlang_big);
-    EI_DECODE_ENCODE_BIG(big  , erlang_big);
-    EI_DECODE_ENCODE_BIG(big  , erlang_big);
+    decode_encode_big(&big_type);
+    decode_encode_big(&big_type);
+    decode_encode_big(&big_type);
 
     /* Test large node containers... */
-    EI_DECODE_ENCODE(pid  , erlang_pid);
-    EI_DECODE_ENCODE(port , erlang_port);
-    EI_DECODE_ENCODE(ref  , erlang_ref);
-    EI_DECODE_ENCODE(pid  , erlang_pid);
-    EI_DECODE_ENCODE(port , erlang_port);
-    EI_DECODE_ENCODE(ref  , erlang_ref);
+    decode_encode_one(&pid_type);
+    decode_encode_one(&port_type);
+    decode_encode_one(&ref_type);
+    decode_encode_one(&pid_type);
+    decode_encode_one(&port_type);
+    decode_encode_one(&ref_type);
 
     /* Unicode atoms */
     for (i=0; i<24; i++) {
-	EI_DECODE_ENCODE(my_atom, my_atom);
-	EI_DECODE_ENCODE(pid, erlang_pid);
-	EI_DECODE_ENCODE(port, erlang_port);
-	EI_DECODE_ENCODE(ref, erlang_ref);
+	decode_encode_one(&my_atom_type);
+	decode_encode_one(&pid_type);
+	decode_encode_one(&port_type);
+	decode_encode_one(&ref_type);
+    }
+
+    decode_encode_one(&tuple_type);  /* {} */
+    {
+	struct Type* tpl[] = { &tuple_type, &my_atom_type, &pid_type, &port_type, &ref_type };
+	decode_encode(tpl, 5);
+    }
+
+    {
+	struct Type* list[] = { &list_type, &my_atom_type, &pid_type, &port_type, &ref_type, &nil_type };
+	decode_encode(list, 6);
+    }
+    {
+	struct Type* list[] = { &list_type, &my_atom_type, &fun_type };
+	decode_encode(list, 3);
+    }
+    decode_encode_one(&map_type);  /* #{} */
+    { /* #{atom => atom}*/
+	struct Type* map[] = { &map_type, &my_atom_type, &my_atom_type };
+	decode_encode(map, 3);
+    }
+
+    { /* #{atom => atom, atom => pid, port => ref }*/
+	struct Type* map[] = { &map_type,
+	    &my_atom_type, &my_atom_type,
+	    &my_atom_type, &pid_type,
+	    &port_type, &ref_type
+	};
+	decode_encode(map, 7);
     }
 
     report(1);
diff --git a/lib/jinterface/java_src/com/ericsson/otp/erlang/AbstractNode.java b/lib/jinterface/java_src/com/ericsson/otp/erlang/AbstractNode.java
index 968f284bff..3ef44b8851 100644
--- a/lib/jinterface/java_src/com/ericsson/otp/erlang/AbstractNode.java
+++ b/lib/jinterface/java_src/com/ericsson/otp/erlang/AbstractNode.java
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  * 
- * Copyright Ericsson AB 2000-2013. All Rights Reserved.
+ * Copyright Ericsson AB 2000-2014. All Rights Reserved.
  * 
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -92,6 +92,7 @@ public class AbstractNode {
     static final int dFlagNewFloats = 0x800;
     static final int dFlagUnicodeIo = 0x1000;
     static final int dFlagUtf8Atoms = 0x10000;
+    static final int dFlagMapTag = 0x20000;
 
     int ntype = NTYPE_R6;
     int proto = 0; // tcp/ip
@@ -100,7 +101,7 @@ public class AbstractNode {
     int creation = 0;
     int flags = dFlagExtendedReferences | dFlagExtendedPidsPorts
 	    | dFlagBitBinaries | dFlagNewFloats | dFlagFunTags
-	    | dflagNewFunTags | dFlagUtf8Atoms;
+	    | dflagNewFunTags | dFlagUtf8Atoms | dFlagMapTag;
 
     /* initialize hostname and default cookie */
     static {
diff --git a/lib/jinterface/java_src/com/ericsson/otp/erlang/OtpErlangMap.java b/lib/jinterface/java_src/com/ericsson/otp/erlang/OtpErlangMap.java
index 7c1cf84e98..03c18e55a2 100644
--- a/lib/jinterface/java_src/com/ericsson/otp/erlang/OtpErlangMap.java
+++ b/lib/jinterface/java_src/com/ericsson/otp/erlang/OtpErlangMap.java
@@ -125,8 +125,6 @@ public class OtpErlangMap extends OtpErlangObject implements Serializable,
 
 	    for (int i = 0; i < arity; i++) {
 		keys[i] = buf.read_any();
-	    }
-	    for (int i = 0; i < arity; i++) {
 		values[i] = buf.read_any();
 	    }
 	} else {
@@ -227,8 +225,6 @@ public class OtpErlangMap extends OtpErlangObject implements Serializable,
 
 	for (int i = 0; i < arity; i++) {
 	    buf.write_any(keys[i]);
-	}
-	for (int i = 0; i < arity; i++) {
 	    buf.write_any(values[i]);
 	}
     }
diff --git a/lib/jinterface/test/jinterface_SUITE_data/Maps.java b/lib/jinterface/test/jinterface_SUITE_data/Maps.java
index 136a665f23..653defc621 100644
--- a/lib/jinterface/test/jinterface_SUITE_data/Maps.java
+++ b/lib/jinterface/test/jinterface_SUITE_data/Maps.java
@@ -42,16 +42,16 @@ class Maps {
 	runTest(new byte[] { (byte) 131, 116, 0, 0, 0, 1, 100, 0, 1, 97, 100,
 		0, 1, 98 }, "#{a => b}", 2);
 	// make sure keys are sorted here, jinterface doesn't reorder them
-	runTest(new byte[] { (byte) 131, 116, 0, 0, 0, 2, 97, 2, 100, 0, 1, 97,
-		106, 97, 1 }, "#{2 => [],a => 1}", 3);
+	runTest(new byte[] { (byte) 131, 116, 0, 0, 0, 2, 97, 2, 106,
+			     100, 0, 1, 97, 97, 1 }, "#{2 => [],a => 1}", 3);
 	runTest(new byte[] { (byte) 131, 116, 0, 0, 0, 1, 104, 1, 97, 3, 108,
 		0, 0, 0, 1, 100, 0, 1, 114, 106 }, "#{{3} => [r]}", 4);
 
 	try {
 	    // #{2 => [],a => 1}
 	    final OtpErlangMap map = new OtpErlangMap(new OtpInputStream(
-		    new byte[] { (byte) 131, 116, 0, 0, 0, 2, 97, 2, 100, 0, 1,
-			    97, 106, 97, 1 }));
+		  new byte[] { (byte) 131, 116, 0, 0, 0, 2, 97, 2, 106,
+			       100, 0, 1, 97, 97, 1 }));
 
 	    if (map.arity() != 2) {
 		fail(5);
diff --git a/lib/kernel/include/dist.hrl b/lib/kernel/include/dist.hrl
index e32c112e63..77556d1303 100644
--- a/lib/kernel/include/dist.hrl
+++ b/lib/kernel/include/dist.hrl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1999-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2014. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -37,3 +37,4 @@
 -define(DFLAG_DIST_HDR_ATOM_CACHE,16#2000).
 -define(DFLAG_SMALL_ATOM_TAGS, 16#4000).
 -define(DFLAG_UTF8_ATOMS, 16#10000).
+-define(DFLAG_MAP_TAG, 16#20000).
diff --git a/lib/kernel/src/dist_util.erl b/lib/kernel/src/dist_util.erl
index fc50ec6717..b127fe2e33 100644
--- a/lib/kernel/src/dist_util.erl
+++ b/lib/kernel/src/dist_util.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1999-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2014. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -116,7 +116,8 @@ make_this_flags(RequestType, OtherNode) ->
 	 ?DFLAG_UNICODE_IO bor
 	 ?DFLAG_DIST_HDR_ATOM_CACHE bor
 	 ?DFLAG_SMALL_ATOM_TAGS bor
-	 ?DFLAG_UTF8_ATOMS).
+	 ?DFLAG_UTF8_ATOMS bor
+	 ?DFLAG_MAP_TAG).
 
 handshake_other_started(#hs_data{request_type=ReqType}=HSData0) ->
     {PreOtherFlags,Node,Version} = recv_name(HSData0),