Bug #12434: Marshal.dump does not dump some numbers as Fixnum

• Status: Rejected
• Assignee: -
• Target version: -
• ruby -v: ruby 2.4.0dev (2016-05-28 trunk 55197) [x86_64-darwin15]
• Backport: 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN

[eitoball (Eito Katagiri)]

Marshal.dump dumps numbers between 1073741824 and 4294967295 and between -4294967296 and -1073741825 as Bignum, but I think that those numbers should be dumped as Fixnum.

$ ./ruby --disable-gems -e'p Marshal.load("\x04\bi\x04\x00\x00\x00\x40")'
1073741824
$ ./ruby --disable-gems -e'p Marshal.dump(1073741824)'
"\x04\bl+\a\x00\x00\x00@"
$ ./ruby --disable-gems -e'p Marshal.load("\x04\bi\xfc\x00\x00\x00\x00")'
-4294967296
$ ./ruby --disable-gems -e'p Marshal.dump(-4294967296)'
"\x04\bl-\b\x00\x00\x00\x00\x01\x00"

I created proposed patch and submit pull request to https://github.com/ruby/ruby/pull/1366

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Rejected

It is intentionally dumped as a Bignum for marshal data compatibility across architectures.

Current behavior:

$ arch -x86_64 ruby -e 'Marshal.dump(1073741824, STDOUT)' | arch -i386 ruby -e 'p Marshal.load(STDIN)'
1073741824

With your patch:

$ .x86_64-darwin/miniruby -e 'Marshal.dump(1073741824, STDOUT)' | .i386-darwin/miniruby -e 'p Marshal.load(STDIN)'
-1073741824

[eitoball (Eito Katagiri)]

Thank you. I should have looked up ruby spec. https://github.com/ruby/spec/blob/master/core/marshal/dump_spec.rb#L40-L48