sort() optimization mishandles numeric comparison between overloaded values #23956
Description
Module:
Description
sort's internal version of the { $a <=> $b } block mishandles fallback comparison of large integer overloaded values.
Found when working on numeric comparison APIs for #23918
Steps to Reproduce
# not properly sorted: $ perl -le 'package Big { use overload "0+" => sub { $_[0][0] }, fallback => 1; } my @x = ( bless([~0], "Big"), bless([~0-1], "Big")); print for sort { $a <=> $b } @x' 18446744073709551615 18446744073709551614 If you prevent the optimisation:
$ perl -le 'package Big { use overload "0+" => sub { $_[0][0] }, fallback => 1; } my @x = ( bless([~0], "Big"), bless([~0-1], "Big")); print for sort { $a <=> 0+$b } @x' 18446744073709551614 18446744073709551615 Expected behavior
Correct comparison in the various amagic comparison functions in pp_sort.c.
Perl configuration
(also in system perl 5.40 and blead)
Summary of my perl5 (revision 5 version 42 subversion 0) configuration: Platform: osname=linux osvers=6.1.0-40-amd64 archname=x86_64-linux-thread-multi uname='linux venus 6.1.0-40-amd64 #1 smp preempt_dynamic debian 6.1.153-1 (2025-09-20) x86_64 gnulinux ' config_args='-des -DDEBUGGING -Doptimize=-O1 -ggdb3 -Dprefix=/home/tony/perl/v5.42.0-debug -Dusethreads' hint=recommended useposix=true d_sigaction=define useithreads=define usemultiplicity=define use64bitint=define use64bitall=define uselongdouble=undef usemymalloc=n default_inc_excludes_dot=define Compiler: cc='cc' ccflags ='-D_REENTRANT -D_GNU_SOURCE -fwrapv -DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2' optimize='-O1 -ggdb3' cppflags='-D_REENTRANT -D_GNU_SOURCE -fwrapv -DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include' ccversion='' gccversion='12.2.0' gccosandvers='' intsize=4 longsize=8 ptrsize=8 doublesize=8 byteorder=12345678 doublekind=3 d_longlong=define longlongsize=8 d_longdbl=define longdblsize=16 longdblkind=3 ivtype='long' ivsize=8 nvtype='double' nvsize=8 Off_t='off_t' lseeksize=8 alignbytes=8 prototype=define Linker and Libraries: ld='cc' ldflags =' -fstack-protector-strong -L/usr/local/lib' libpth=/usr/local/lib /usr/lib/x86_64-linux-gnu /usr/lib /usr/lib64 libs=-lpthread -lgdbm -ldl -lm -lcrypt -lutil -lc -lgdbm_compat perllibs=-lpthread -ldl -lm -lcrypt -lutil -lc libc=/lib/x86_64-linux-gnu/libc.so.6 so=so useshrplib=false libperl=libperl.a gnulibc_version='2.36' Dynamic Linking: dlsrc=dl_dlopen.xs dlext=so d_dlsymun=undef ccdlflags='-Wl,-E' cccdlflags='-fPIC' lddlflags='-shared -O1 -ggdb3 -L/usr/local/lib -fstack-protector-strong' Characteristics of this binary (from libperl): Compile-time options: DEBUGGING HAS_LONG_DOUBLE HAS_STRTOLD HAS_TIMES MULTIPLICITY PERLIO_LAYERS PERL_COPY_ON_WRITE PERL_DONT_CREATE_GVSV PERL_HASH_FUNC_SIPHASH13 PERL_HASH_USE_SBOX32 PERL_MALLOC_WRAP PERL_OP_PARENT PERL_PRESERVE_IVUV PERL_TRACK_MEMPOOL PERL_USE_SAFE_PUTENV USE_64_BIT_ALL USE_64_BIT_INT USE_ITHREADS USE_LARGE_FILES USE_LOCALE USE_LOCALE_COLLATE USE_LOCALE_CTYPE USE_LOCALE_NUMERIC USE_LOCALE_TIME USE_PERLIO USE_PERL_ATOF USE_REENTRANT_API USE_THREAD_SAFE_LOCALE Built under linux Compiled at Oct 29 2025 22:32:30 %ENV: PERLBREW_BASHRC_VERSION="0.43" PERLBREW_HOME="/home/tony/.perlbrew" PERLBREW_MANPATH="" PERLBREW_PATH="/home/tony/perl5/perlbrew/bin" PERLBREW_ROOT="/home/tony/perl5/perlbrew" PERLBREW_VERSION="0.67" @INC: /home/tony/perl/v5.42.0-debug/lib/site_perl/5.42.0/x86_64-linux-thread-multi /home/tony/perl/v5.42.0-debug/lib/site_perl/5.42.0 /home/tony/perl/v5.42.0-debug/lib/5.42.0/x86_64-linux-thread-multi /home/tony/perl/v5.42.0-debug/lib/5.42.0