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.

1 files changed, 6 insertions, 5 deletions

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;