[PATCH] correct conversion of MIN_SMALL numeral to fixnum
Mikael Pettersson <[email protected]> Wed, 20 Aug 2014 09:53:52 +0200
| Newsgroups | gmane.comp.lang.erlang.patches |
|---|---|
| Message-ID | <[email protected]> |
Conversion of MIN_SMALL as a numeral to an Erlang integer, via binary_to_integer/1 or list_to_integer/1, succeeds but creates the integer as a negative bignum. This is incorrect as (a) the value fits in a fixnum, and (b) the VM expects values that fit in fixnums to also be fixnums. The bug is that the numeral is converted first as a non-negative number, and then finally negated if prefixed by a unary minus sign. MIN_SMALL without the sign is MAX_SMALL+1, which doesn't fit in a fixnum, so the value before the negation is a bignum. To correct the representation after the negation call big_plus_small with zero, as already done in other places. Tested with the emulator testsuite on Linux/x86_64, no regressions. Thanks to Jesper Louis Andersen for the report to erlang-bugs. Signed-off-by: Mikael Pettersson <[email protected]> Links: git fetch git://github.com/mikpe/otp.git MIN_SMALL-to-integer https://github.com/mikpe/otp/compare/erlang:maint...MIN_SMALL-to-integer https://github.com/mikpe/otp/compare/erlang:maint...MIN_SMALL-to-integer.patch https://github.com/erlang/otp/pull/452 _______________________________________________ erlang-patches mailing list [email protected] http://erlang.org/mailman/listinfo/erlang-patches