erts: Correct conversion of MIN_SMALL numeral to fixnum

list_to_integer and binary_to_integer returned un-normalized bignum for
-134217728 on 32-bit and -576460752303423488 on 64-bit.

Thanks to Jesper Louis Andersen, Mikael Pettersson
and Anthony Ramine for report, initial patch and optimization suggestion.

3 files changed, 28 insertions, 28 deletions

diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index fcbeb6cf5c..b835946729 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  *
- * Copyright Ericsson AB 1996-2013. All Rights Reserved.
+ * Copyright Ericsson AB 1996-2014. 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
@@ -2887,9 +2887,6 @@ static int do_list_to_integer(Process *p, Eterm orig_list,
 	     res = big_plus_small(res, m, hp);
 	 }
 
-	 if (is_big(res))  /* check if small */
-	     res = big_plus_small(res, 0, hp); /* includes conversion to small */
-	 
 	 if (neg) {
 	     if (is_small(res))
 		 res = make_small(-signed_val(res));
@@ -2899,8 +2896,12 @@ static int do_list_to_integer(Process *p, Eterm orig_list,
 	     }
 	 }
 
-	 if (is_big(res)) {
-	     hp += (big_arity(res)+1);
+	 if (is_not_small(res)) {
+	     res = big_plus_small(res, 0, hp); /* includes conversion to small */
+
+	     if (is_not_small(res)) {
+		 hp += (big_arity(res)+1);
+	     }
 	 }
 	 HRelease(p,hp_end,hp);
      }
diff --git a/erts/emulator/beam/big.c b/erts/emulator/beam/big.c
index e62caa6b22..a8710dd910 100644
--- a/erts/emulator/beam/big.c
+++ b/erts/emulator/beam/big.c
@@ -2675,9 +2675,6 @@ Eterm erts_chars_to_integer(Process *BIF_P, char *bytes,
 	res = big_plus_small(res, m, hp);
     }
 
-    if (is_big(res)) /* check if small */
-	res = big_plus_small(res, 0, hp); /* includes conversion to small */
-
     if (neg) {
 	if (is_small(res))
 	    res = make_small(-signed_val(res));
@@ -2687,8 +2684,12 @@ Eterm erts_chars_to_integer(Process *BIF_P, char *bytes,
 	}
     }
 
-    if (is_big(res)) {
-	hp += (big_arity(res) + 1);
+    if (is_not_small(res)) {
+	res = big_plus_small(res, 0, hp); /* includes conversion to small */
+
+	if (is_not_small(res)) {
+	    hp += (big_arity(res) + 1);
+	}
     }
     HRelease(BIF_P, hp_end, hp);
     goto bytebuf_to_integer_1_done;
diff --git a/erts/emulator/test/num_bif_SUITE.erl b/erts/emulator/test/num_bif_SUITE.erl
index ff8d18eef8..8cf8377c30 100644
--- a/erts/emulator/test/num_bif_SUITE.erl
+++ b/erts/emulator/test/num_bif_SUITE.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1997-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2014. 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
@@ -394,18 +394,15 @@ t_string_to_integer(Config) when is_list(Config) ->
     test_sti(268435455),
     test_sti(-268435455),
 
-    %% 1 bsl 28 - 1, just before 32 bit bignum
-    test_sti(1 bsl 28 - 1),
-    %% 1 bsl 28, just beyond 32 bit small
-    test_sti(1 bsl 28),
-    %% 1 bsl 33, just beyond 32 bit
-    test_sti(1 bsl 33),
-    %% 1 bsl 60 - 1, just before 64 bit bignum
-    test_sti(1 bsl 60 - 1),
-    %% 1 bsl 60, just beyond 64 bit small
-    test_sti(1 bsl 60),
-    %% 1 bsl 65, just beyond 64 bit
-    test_sti(1 bsl 65),
+    % Interesting values around 2-pows, such as MIN_SMALL and MAX_SMALL.
+    lists:foreach(fun(Bits) ->
+			  N = 1 bsl Bits,
+			  test_sti(N - 1),
+			  test_sti(N),
+			  test_sti(N + 1)
+		  end,
+		  lists:seq(16, 130)),
+
     %% Bignums.
     test_sti(123456932798748738738,16),
     test_sti(list_to_integer(lists:duplicate(2000, $1))),
@@ -454,10 +451,11 @@ test_sti(Num) ->
      end|| Base <- lists:seq(2,36)].
 
 test_sti(Num,Base) ->
-    Num  = list_to_integer(int2list(Num,Base),Base),
-    Num = -1*list_to_integer(int2list(Num*-1,Base),Base),
-    Num  = binary_to_integer(int2bin(Num,Base),Base),
-    Num = -1*binary_to_integer(int2bin(Num*-1,Base),Base).
+    Neg = -Num,
+    Num = list_to_integer(int2list(Num,Base),Base),
+    Neg = list_to_integer(int2list(Num*-1,Base),Base),
+    Num = binary_to_integer(int2bin(Num,Base),Base),
+    Neg = binary_to_integer(int2bin(Num*-1,Base),Base).
 
 % Calling this function (which is not supposed to be inlined) prevents
 % the compiler from calculating the answer, so we don't test the compiler