[ruby-core:44667] possible YAML bug in ruby 1.9.3p125?

YAML in ruby 1.9.3p125 seems to have a bug reading in YAML from older Ruby versions.  Specifically, YAML in 1.9.3p125 mis-parses text like "123_456" as a number (just as in Ruby) rather than as a string, which appears to be the correct behavior according to the YAML specification.

You can reproduce by

(1) Generate YAML from an older ruby (e.g., 1.9.2):
 
>> YAML::dump ["123_456", 789789]
=> "---\n- 123_456\n- 789789\n"

(2) Load the YAML document from 1.9.3p125:

>> YAML::load "---\n- 123_456\n- 789789\n"
=> [123456, 789789]

Ruby 1.9.3p125 works fine round-tripping with itself:

>> x = YAML::dump ["123_456", 789789]
=> "---\n- '123_456'\n- 789789\n"
>> YAML::load x
=> ["123_456", 789789]

Is this a bug in ruby 1.9.3p125 or in the earlier Ruby versions?


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