Bug #2957 for YAML: Serializing array-elements with dashes

I got some good practice out of the Perl debugger on this one. I oughta use that more. :-) Serializing the example Perl code resulted in what YAML terminology calls "in-line nested mapping." The bug causes failure if and when the first (or only) line in an in-line nested mapping uses a quoted string for a key. Line 379 in YAML/Loader.pm (in the _parse_seq subroutine) appears to be the critical point where some markup on a "-" line is examined to see whether it's an in-line mapping: if ($self->preface =~ /^(\s*)(\w.*\:(?: |$).*)$/) {...} This doesn't catch the case where the key is a quoted string, so the wrong branch is taken and parsing falls apart. (In the case of a single-line nested mapping like the example submitted, it chokes with YAML_PARSE_ERR_SINGLE_LINE; if there is more than one line and the first line uses a quoted key, it chokes with YAML_PARSE_ERR_INCONSISTENT_INDENTATION.) I'm attaching a patch I made to fix this. It uses extra regexes to catch single- and double-quoted keys here. This may not be the best way to go about it, but it seems to resolve the bug. I also took the liberty of enabling the relevant test in t/bugs-rt.t (it passes). --Larry Gilbert

Index: YAML/t/bugs-rt.t =================================================================== --- YAML/t/bugs-rt.t (revision 5) +++ YAML/t/bugs-rt.t (working copy) @@ -1,4 +1,4 @@ -use t::TestYAML tests => 41; +use t::TestYAML tests => 42; run_yaml_tests; @@ -59,8 +59,10 @@ -=== Ticket #2957 Serializing array-elements with dashes -+++ skip_this_for_now +=== Ticket #2957 Serializing array-elements with dashes [sic] +(Actually, the real problem is not with hyphens but with spaces in the hash +key. This gets serialized as a quoted string, and the bug prevents the quoted +string from being parsed correctly.) +++ perl: [ { "test - " => 23 } ]; +++ yaml --- Index: YAML/lib/YAML/Loader.pm =================================================================== --- YAML/lib/YAML/Loader.pm (revision 5) +++ YAML/lib/YAML/Loader.pm (working copy) @@ -376,7 +376,15 @@ else { $self->die('YAML_LOAD_ERR_BAD_SEQ_ELEMENT'); } - if ($self->preface =~ /^(\s*)(\w.*\:(?: |$).*)$/) { + # Check whether the preface looks like a YAML mapping ("key: value"). + # This is complicated because it has to account for the possibility + # that a key is a quoted string, which itself may contain escaped + # quotes. + my $preface = $self->preface; + if ( $preface =~ /^ (\s*) ( \w .*? \: (?:\ |$).*) $/x or + $preface =~ /^ (\s*) ('\w .*? (?<!\\) ' \s* \: (?:\ |$).*) $/x or + $preface =~ /^ (\s*) ("\w .*? (?<!\\) " \s* \: (?:\ |$).*) $/x + ) { $self->indent($self->offset->[$self->level] + 2 + length($1)); $self->content($2); $self->level($self->level + 1);