Bug #1311: YAML::dump creates strings YAML::load cannot parse

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 1.8.6 (2007-03-13 patchlevel 0) [powerpc-darwin8.9.0], ruby 1.8.7 (2008-05-31 patchlevel 0) [i686-darwin9.3.0]

[rampion (Noah Easterly)]

=begin
This case seems to occur whenever

• the string begins with a newline, and
• the last line doesn't end in whitespace (except, perhaps, newlines), and
• the second line (after the initial whitespace) begins with more whitespace than some later line

Here are a couple example strings:

• "\n a\nb"
• "\n a\n b\nc"
• "\n a\n b"

YAML::load throws an ArgumentError with a syntax error on the line that begins with less leading
whitespace.

• YAML.load YAML.dump("\n a\nb") #=> ArgumentError: syntax error on line 3, col 0: `b'
• YAML.load YAML.dump("\n a\n b\nc") #=> ArgumentError: syntax error on line 4, col 0: `c'
• YAML.load YAML.dump("\n a\n b") #=> ArgumentError: syntax error on line 3, col 1: ` b'

This has been observed in ruby-1.8.6p0 and ruby-1.8.7p0.

Here is another observation of this same bug: http://blog.smartlogicsolutions.com/2008/09/04/ruby-patch-to-fix-broken-yamldump-for-multi-line-strings-stringto_yaml/
=end

[rampion (Noah Easterly)]

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Correction: should read "the second line (after the initial newline)"

=end

[daz (Dave B)]

• File syck_scan_scalar.patch syck_scan_scalar.patch added
• File test_yaml.patch test_yaml.patch added

=begin
Good reports, thanks.

I've found a workaround but I'm not sure enough about the YAML spec to guarantee that it's the correct fix.

The patch is mild - it just forces one style over another in the same way as the existing code and allows the new tests to pass along with the rest.

Two patches to 1.9.2dev - these files don't change often ;)

?CHANGELOG: Wed Mar 25 20:06:10 2009 Dave B [e-mail]
* ext/syck/emitter.c: Set SCAN_WHITEEDGE flag when
scalar begins with newline [ruby-core:23006][Bug #1311]

        * test/yaml/test_yaml.rb: add new tests and comment old
          Test::Unit::TestSuite code to enable them to run as $0

=end

[coatl (caleb clausen)]

• File test_yaml2.patch test_yaml2.patch added
• File syck_scan_scalar2.patch syck_scan_scalar2.patch added

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I have also been bitten by this same bug. In addition to the cases described above, this problem also occurs when the input contains just a single newline (in either unix or dos style). The patch supplied by Dave B fixes the case of a string containing just a single unix newline, but fails to fix a string with just a single dos newline (and probably the other cases initially reported, if the unix newlines are converted to dos newlines). I'm attaching slightly a slightly modified patches, which addresses the dos newline issue, and tests single dos and unix newlines.

This problem also occurs in ruby 1.9.
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[daz (Dave B)]

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Caleb's revisions are the way to go.

( test_yaml2.patch & syck_scan_scalar2.patch )

Harmlessly beneficial - no compatibility issues - emits YAML to the spec.

daz

=end

[weppos (Simone Carletti)]

• File yaml-error.txt yaml-error.txt added

=begin
Here's an other test case for a similar issue.

require 'yaml'

c = File.read("yaml-error.txt")
YAML.load(YAML.dump(c))
'rgumentError: syntax error on line 34, col 0: -- from /Users/weppos/.rvm/ruby-1.8.7-p248/lib/ruby/1.8/yaml.rb:133:in load'
from /Users/weppos/.rvm/ruby-1.8.7-p248/lib/ruby/1.8/yaml.rb:133:in `load'
from (irb):3
=end

[mame (Yusuke Endoh)]

• Status changed from Open to Closed

=begin
Hi,

Syck is deprecated, in effect. This issue won't be fixed.
Instead, try Psych. [ruby-core:29337]

--
Yusuke Endoh [e-mail]
=end

[coatl (caleb clausen)]

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Yusuke Endoh and I have verified that all of the test cases reported here are fixed when using psych. For proof of most, see [ruby-core:29323]. And I just now verified the last test case is now ok, submitted by Simone Carletti. (No console dump, sorry.)
=end

[nobu (Nobuyoshi Nakada)]

• Status changed from Closed to Open

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=end

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

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This issue was solved with changeset r27591.
Noah, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

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