Merge branch 'hasse/dialyzer/extra-range/OTP-14970'

* hasse/dialyzer/extra-range/OTP-14970:
  ssl: Correct some specs
  os_mon: Correct a spec
  Fix broken spec in beam_asm
  Dialyzer should not throw away spec information because of overspec

11 files changed, 98 insertions, 15 deletions

diff --git a/lib/compiler/src/beam_asm.erl b/lib/compiler/src/beam_asm.erl
index fa919ca862..5ef340c831 100644
--- a/lib/compiler/src/beam_asm.erl
+++ b/lib/compiler/src/beam_asm.erl
@@ -475,7 +475,7 @@ encode_alloc_list_1([{floats,Floats}|T], Dict, Acc0) ->
 encode_alloc_list_1([], Dict, Acc) ->
     {iolist_to_binary(Acc),Dict}.
 
--spec encode(non_neg_integer(), pos_integer()) -> iodata().
+-spec encode(non_neg_integer(), integer()) -> iodata().
 
 encode(Tag, N) when N < 0 ->
     encode1(Tag, negative_to_bytes(N));
diff --git a/lib/dialyzer/src/dialyzer_contracts.erl b/lib/dialyzer/src/dialyzer_contracts.erl
index e72c1aecfc..0df15e55f9 100644
--- a/lib/dialyzer/src/dialyzer_contracts.erl
+++ b/lib/dialyzer/src/dialyzer_contracts.erl
@@ -197,6 +197,10 @@ check_contracts(Contracts, Callgraph, FunTypes, ModOpaques) ->
 		      false ->
 			[{MFA, Contract}|NewContracts]
 		    end;
+                  {error, {extra_range, _, _}} ->
+                    %% do not treat extra range as an error in this check
+                    %% since that prevents discovering other actual errors
+                    [{MFA, Contract}|NewContracts];
 		  {error, _Error} -> NewContracts
 		end;
 	      error -> NewContracts
diff --git a/lib/dialyzer/test/small_SUITE_data/results/chars b/lib/dialyzer/test/small_SUITE_data/results/chars
index 2c1f8f8d17..72fbdb4528 100644
--- a/lib/dialyzer/test/small_SUITE_data/results/chars
+++ b/lib/dialyzer/test/small_SUITE_data/results/chars
@@ -1,4 +1,4 @@
 
-chars.erl:29: Invalid type specification for function chars:f/1. The success typing is (#{'b':=50}) -> 'ok'
-chars.erl:32: Function t1/0 has no local return
-chars.erl:32: The call chars:f(#{'b':=50}) breaks the contract (#{'a':=49,'b'=>50,'c'=>51}) -> 'ok'
+chars.erl:37: Invalid type specification for function chars:f/1. The success typing is (#{'b':=50}) -> 'ok'
+chars.erl:40: Function t1/0 has no local return
+chars.erl:40: The call chars:f(#{'b':=50}) breaks the contract (#{'a':=49,'b'=>50,'c'=>51}) -> 'ok'
diff --git a/lib/dialyzer/test/small_SUITE_data/results/extra_range b/lib/dialyzer/test/small_SUITE_data/results/extra_range
new file mode 100644
index 0000000000..ec50c95c4e
--- /dev/null
+++ b/lib/dialyzer/test/small_SUITE_data/results/extra_range
@@ -0,0 +1,4 @@
+
+extra_range.erl:29: The pattern 'ok' can never match the type 'error'
+extra_range.erl:43: The pattern 'no' can never match the type 'maybe' | 'yes'
+extra_range.erl:58: The pattern 'maybe' can never match the type 'no' | 'yes'
diff --git a/lib/dialyzer/test/small_SUITE_data/src/chars.erl b/lib/dialyzer/test/small_SUITE_data/src/chars.erl
index 1e9c8ab6b9..62b90cf54d 100644
--- a/lib/dialyzer/test/small_SUITE_data/src/chars.erl
+++ b/lib/dialyzer/test/small_SUITE_data/src/chars.erl
@@ -12,17 +12,25 @@
 -spec t() -> $0-$0..$9-$0| $?.
 
 t() ->
-    c(#r{f = $z - 3}),
+    r(#r{f = $z - 3}),
+    r(#r{f = 97}),
+    c($/),
     c($z - 3),
     c($B).
 
 -spec c(cs()) -> $3-$0..$9-$0.
-
-c($A + 1) -> 2;
+c($A + 1) -> $9-$0;
 c(C) ->
     case C of
-        $z - 3 -> 3;
-        #r{f = $z - 3} -> 7
+        $z - 3 -> $3-$0;
+        _ -> $7-$0
+    end.
+
+-spec r(#r{f :: $a..$z}) -> ok | error.
+r(R) ->
+    case R of
+        #r{f = $z - 3} -> error;
+        _ -> ok
     end.
 
 %% Display contract with character in warning:
diff --git a/lib/dialyzer/test/small_SUITE_data/src/extra_range.erl b/lib/dialyzer/test/small_SUITE_data/src/extra_range.erl
new file mode 100644
index 0000000000..9d6ba89c95
--- /dev/null
+++ b/lib/dialyzer/test/small_SUITE_data/src/extra_range.erl
@@ -0,0 +1,59 @@
+%% Test that a spec containing more items than actually returned
+%% (whether by accident or by benign overspeccing) does not prevent
+%% detection of impossible matches.
+
+-module(extra_range).
+
+-export([t1/2, t2/2, t3/2, t4/2]).
+
+-dialyzer([no_return]).
+
+%% this spec matches the behaviour of the code
+-spec normal(integer()) -> ok | error.
+normal(1) -> ok;
+normal(2) -> error.
+
+t1(X, Y) when is_integer(X), is_integer(Y) ->
+    ok = normal(X),
+    error = normal(Y),
+    ok.
+
+
+%% this spec has a typo, which should cause anyone trying to match on
+%% `ok = typo(X)' to get a warning, because `ok' is not in the spec
+-spec typo(integer()) -> ook | error.
+typo(1) -> ok;
+typo(2) -> error.
+
+t2(X, Y) when is_integer(X), is_integer(Y) ->
+    ok = typo(X),  % warning expected - not allowed according to spec
+    error = typo(Y),
+    ok.
+
+
+%% this is overspecified, and should cause a warning for trying
+%% to match on `no = over(X)', because it cannot succeed and either
+%% the spec should be updated or the code should be extended
+-spec over(integer()) -> yes | no | maybe.
+over(1) -> yes;
+over(_) -> maybe.
+
+t3(X, Y) when is_integer(X), is_integer(Y) ->
+    yes = over(X),
+    no = over(Y),  % warning expected - spec or code needs fixing
+    maybe = over(X + Y),
+    ok.
+
+
+%% this is underspecified, which should cause anyone trying to match on
+%% `maybe = under(X)' to get a warning, because `maybe' is not in the spec
+-spec under(integer()) -> yes | no.
+under(1) -> yes;
+under(2) -> no;
+under(_) -> maybe.
+
+t4(X, Y) when is_integer(X), is_integer(Y) ->
+    yes = under(X),
+    no = under(Y),
+    maybe = under(X + Y), % warning expected - not in spec
+    ok.
diff --git a/lib/os_mon/src/disksup.erl b/lib/os_mon/src/disksup.erl
index aeec335ba7..5118d807e1 100644
--- a/lib/os_mon/src/disksup.erl
+++ b/lib/os_mon/src/disksup.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2018. All Rights Reserved.
 %% 
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
@@ -357,7 +357,7 @@ parse_df_take_word_percent(Input) ->
 %% and capacity), skip % sign, (optionally for susv3 can also skip IUsed, IFree
 %% and ICap% fields) then take remaining characters as the mount path
 -spec parse_df(string(), posix | susv3) ->
-    {error, parse_df} | {ok, {integer(), integer(), integer()}, string()}.
+    {error, parse_df} | {ok, {integer(), integer(), list()}, string()}.
 parse_df(Input0, Flavor) ->
     %% Format of Posix/Linux df output looks like Header + Lines
     %% Filesystem     1024-blocks     Used Available Capacity Mounted on
diff --git a/lib/ssl/src/ssl_alert.erl b/lib/ssl/src/ssl_alert.erl
index 95ab955ad0..fc7b1e6d1c 100644
--- a/lib/ssl/src/ssl_alert.erl
+++ b/lib/ssl/src/ssl_alert.erl
@@ -48,7 +48,9 @@ decode(Bin) ->
     decode(Bin, [], 0).
 
 %%--------------------------------------------------------------------
--spec reason_code(#alert{}, client | server) -> closed | {essl, string()}.
+-spec reason_code(#alert{}, client | server) ->
+                         closed | {tls_alert, unicode:chardata()}.
+%-spec reason_code(#alert{}, client | server) -> closed | {essl, string()}.
 %%
 %% Description: Returns the error reason that will be returned to the
 %% user.
diff --git a/lib/ssl/src/ssl_cipher.erl b/lib/ssl/src/ssl_cipher.erl
index a83ce42455..6e436aa7c0 100644
--- a/lib/ssl/src/ssl_cipher.erl
+++ b/lib/ssl/src/ssl_cipher.erl
@@ -239,7 +239,7 @@ decipher(?AES_CBC, HashSz, CipherState, Fragment, Version, PaddingCheck) ->
 
 %%--------------------------------------------------------------------
 -spec decipher_aead(cipher_enum(),  #cipher_state{}, integer(), binary(), binary(), ssl_record:ssl_version()) ->
-			   {binary(), binary(), #cipher_state{}} | #alert{}.
+			   {binary(), #cipher_state{}} | #alert{}.
 %%
 %% Description: Decrypts the data and checks the associated data (AAD) MAC using
 %% cipher described by cipher_enum() and updating the cipher state.
diff --git a/lib/ssl/src/ssl_handshake.erl b/lib/ssl/src/ssl_handshake.erl
index 09160e2f9c..9e2b12b186 100644
--- a/lib/ssl/src/ssl_handshake.erl
+++ b/lib/ssl/src/ssl_handshake.erl
@@ -189,12 +189,18 @@ certificate_request(CipherSuite, CertDbHandle, CertDbRef, HashSigns, Version) ->
 		   {dh, binary()} |
 		   {dh, {binary(), binary()}, #'DHParameter'{}, {HashAlgo::atom(), SignAlgo::atom()},
 		   binary(), binary(), public_key:private_key()} |
+		   {ecdh, _, _, _, _, _} |
 		   {ecdh, #'ECPrivateKey'{}} |
+		   {psk, _, _, _, _, _} |
 		   {psk, binary()} |
+		   {dhe_psk, _, _, _, _, _, _, _} |
 		   {dhe_psk, binary(), binary()} |
+		   {ecdhe_psk, _, _, _, _, _, _} |
 		   {ecdhe_psk, binary(), #'ECPrivateKey'{}} |
 		   {srp, {binary(), binary()}, #srp_user{}, {HashAlgo::atom(), SignAlgo::atom()},
-		   binary(), binary(), public_key:private_key()}) ->
+                    binary(), binary(), public_key:private_key()} |
+		   {srp, _} |
+                   {psk_premaster_secret, _, _, _}) ->
     #client_key_exchange{} | #server_key_exchange{}.
 
 %%
diff --git a/lib/ssl/src/ssl_record.erl b/lib/ssl/src/ssl_record.erl
index dd6a3e8521..c0eee466ae 100644
--- a/lib/ssl/src/ssl_record.erl
+++ b/lib/ssl/src/ssl_record.erl
@@ -326,7 +326,7 @@ cipher_aead(Version, Fragment,
 
 %%--------------------------------------------------------------------
 -spec decipher(ssl_version(), binary(), connection_state(), boolean()) ->
-                      {binary(), binary(), connection_state} | #alert{}.
+                      {binary(), binary(), connection_state()} | #alert{}.
 %%
 %% Description: Payload decryption
 %%--------------------------------------------------------------------