[Yaml-core] bug with quoting of strings containing brackets

[Joe C. <jc...@un...>]

Hi,

This simple program fails because of the brackets in the data:

  %data = ('test [1]' => 1);
  $yaml = YAML::Dump(\%data);
  $data = YAML::Load($yaml);

The dump doesn't quote the string "test [1]", which causes the load to get
this error:

  --- !perl/YAML::Error
  code: YAML_LOAD_ERR_BAD_MAP_ELEMENT
  msg: Invalid element in map
  line: 2
  document: 1
  ...

(I'm using version 0.35.)  I find it hard to believe that yaml handles all
sorts of complicated data types but can't handle brackets in strings.  Has
anyone else run into this problem?

I think I found a way to fix it but I'm not sure if it will break anything
else.  In sub is_valid_implicit in yaml.pm, I commented out this line:

    return 1 if $_[0] =~ /^\w/;                       # !str

and I added this line:

    return 0 if $_[0] =~ /\W/;

So any string containing punctuation or spaces will be quoted by sub
_emit_str.  Any feedback on the problem or on my fix would be appreciated.
Thanks.

-Joe