YAML 1.2 allows empty implicit keys in block style mappings0.15.92

fixes issue #284


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*(You can do so using the WorkFlow pull-down (close to the top right of this page))*

10 files changed, 57 insertions, 23 deletions

diff --git a/.readthedocs.yml b/.readthedocs.yaml
index 914f036..914f036 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yaml
diff --git a/CHANGES b/CHANGES
index ab457f6..47da0c6 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,7 @@
+[0, 15, 92]: 2019-04-16
+  - fix failure to parse empty implicit block mapping key (reported by 
+    `Nolan W <https://bitbucket.org/i2labs/>`__)
+
 [0, 15, 91]: 2019-04-05
   - allowing duplicate keys would not work for merge keys (reported by mamacdon on
     `StackOverflow <https://stackoverflow.com/questions/55540686/>`__ 
diff --git a/README.rst b/README.rst
index f359efc..7547f69 100644
--- a/README.rst
+++ b/README.rst
@@ -4,8 +4,8 @@ ruamel.yaml
 
 ``ruamel.yaml`` is a YAML 1.2 loader/dumper package for Python.
 
-:version:       0.15.91
-:updated:       2019-04-05
+:version:       0.15.92
+:updated:       2019-04-16
 :documentation: http://yaml.readthedocs.io
 :repository:    https://bitbucket.org/ruamel/
 :pypi:          https://pypi.org/project/ruamel.yaml/
@@ -54,6 +54,10 @@ ChangeLog
 
 .. should insert NEXT: at the beginning of line for next key (with empty line)
 
+0.15.92 (2019-04-16):
+  - fix failure to parse empty implicit block mapping key (reported by 
+    `Nolan W <https://bitbucket.org/i2labs/>`__)
+
 0.15.91 (2019-04-05):
   - allowing duplicate keys would not work for merge keys (reported by mamacdon on
     `StackOverflow <https://stackoverflow.com/questions/55540686/>`__ 
diff --git a/__init__.py b/__init__.py
index d1481e1..eb374fc 100644
--- a/__init__.py
+++ b/__init__.py
@@ -7,8 +7,8 @@ if False:  # MYPY
 
 _package_data = dict(
     full_package_name='ruamel.yaml',
-    version_info=(0, 15, 91),
-    __version__='0.15.91',
+    version_info=(0, 15, 92),
+    __version__='0.15.92',
     author='Anthon van der Neut',
     author_email='a.van.der.neut@ruamel.eu',
     description='ruamel.yaml is a YAML parser/emitter that supports roundtrip preservation of comments, seq/map flow style, and map key order',  # NOQA
diff --git a/_doc/Makefile b/_doc/Makefile
index 630532d..c5d1aa0 100644
--- a/_doc/Makefile
+++ b/_doc/Makefile
@@ -4,7 +4,7 @@
 # You can set these variables from the command line.
 SPHINXOPTS    =
 SPHINXBUILD   = sphinx-build
-PAPER         =
+PAPER         = a4
 BUILDDIR      = _build
 
 # User-friendly check for sphinx-build
diff --git a/_doc/_static/pypi.svg b/_doc/_static/pypi.svg
index 6bc0f5e..d1ffe22 100644
--- a/_doc/_static/pypi.svg
+++ b/_doc/_static/pypi.svg
@@ -1 +1 @@
-<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="86" height="20"><linearGradient id="b" x2="0" y2="100%"><stop offset="0" stop-color="#bbb" stop-opacity=".1"/><stop offset="1" stop-opacity=".1"/></linearGradient><clipPath id="a"><rect width="86" height="20" rx="3" fill="#fff"/></clipPath><g clip-path="url(#a)"><path fill="#555" d="M0 0h33v20H0z"/><path fill="#007ec6" d="M33 0h53v20H33z"/><path fill="url(#b)" d="M0 0h86v20H0z"/></g><g fill="#fff" text-anchor="middle" font-family="DejaVu Sans,Verdana,Geneva,sans-serif" font-size="110"> <text x="175" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="230">pypi</text><text x="175" y="140" transform="scale(.1)" textLength="230">pypi</text><text x="585" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="430">0.15.91</text><text x="585" y="140" transform="scale(.1)" textLength="430">0.15.91</text></g> </svg>
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="86" height="20"><linearGradient id="b" x2="0" y2="100%"><stop offset="0" stop-color="#bbb" stop-opacity=".1"/><stop offset="1" stop-opacity=".1"/></linearGradient><clipPath id="a"><rect width="86" height="20" rx="3" fill="#fff"/></clipPath><g clip-path="url(#a)"><path fill="#555" d="M0 0h33v20H0z"/><path fill="#007ec6" d="M33 0h53v20H33z"/><path fill="url(#b)" d="M0 0h86v20H0z"/></g><g fill="#fff" text-anchor="middle" font-family="DejaVu Sans,Verdana,Geneva,sans-serif" font-size="110"> <text x="175" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="230">pypi</text><text x="175" y="140" transform="scale(.1)" textLength="230">pypi</text><text x="585" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="430">0.15.92</text><text x="585" y="140" transform="scale(.1)" textLength="430">0.15.92</text></g> </svg>
diff --git a/_doc/api.ryd b/_doc/api.ryd
index a295565..314bfbd 100644
--- a/_doc/api.ryd
+++ b/_doc/api.ryd
@@ -95,7 +95,7 @@ all functionality of the old interface will be available via
 ``YAML`` instances (if you are using something that isn't let me know).
 
 If a parse or dump fails, and throws and exception, the state of the
-`YAML()` instance is not guaranteed to be able to handle further
+``YAML()`` instance is not guaranteed to be able to handle further
 processing. You should, at that point to recreate the YAML instance before
 proceeding.
 
@@ -158,7 +158,7 @@ works for output (dumping) only, requires you to specify the output
 Within the context manager, you cannot use the ``dump()`` with a
 second (stream) argument, nor can you use ``dump_all()``. The
 ``dump()`` within the context of the ``YAML()`` automatically creates
- multi-document if called more than once.
+multi-document if called more than once.
 
 To combine multiple YAML documents from multiple files:
 
diff --git a/_doc/conf.py b/_doc/conf.py
index f0fbcad..610eecb 100644
--- a/_doc/conf.py
+++ b/_doc/conf.py
@@ -36,7 +36,7 @@ templates_path = ['_templates']
 # The suffix(es) of source filenames.
 # You can specify multiple suffix as a list of string:
 # source_suffix = ['.rst', '.md']
-source_suffix = '.rst'
+source_suffix = {'.rst': 'restructuredtext', '.ryd': 'ryd2rst'}
 
 # The encoding of source files.
 # source_encoding = 'utf-8-sig'
@@ -46,7 +46,7 @@ master_doc = 'index'
 
 # General information about the project.
 project = u'yaml'
-copyright = u'2017-2018, Anthon van der Neut, Ruamel bvba'
+copyright = u'2017-2019, Anthon van der Neut, Ruamel bvba'
 author = u'Anthon van der Neut'
 
 # The version info for the project you're documenting, acts as replacement for
@@ -67,20 +67,26 @@ print('ruamel.yaml version', version)
 # print('cwd:', os.getcwd())
 # current working directory is the one with `conf.py` !
 
-try:
-    from ryd.__main__ import RYDCmd
-    from ruamel.std.pathlib import Path
 
-    oldargv = sys.argv
-    for fn in Path('.').glob('*.ryd'):
-        sys.argv = ['ryd', 'convert', '--no-pdf', str(fn)]
-        rc = RYDCmd()
-        rc.parse_args()
-        print(sys.argv, '->', rc.run())
-    sys.argv = oldargv
+class ryd2rst:
+    pass
 
-except Exception as e:
-    print('ryd exception', e)
+
+if False:
+    try:
+        from ryd.__main__ import RYDCmd
+        from ruamel.std.pathlib import Path
+
+        oldargv = sys.argv
+        for fn in Path('.').glob('*.ryd'):
+            sys.argv = ['ryd', 'convert', '--no-pdf', str(fn)]
+            rc = RYDCmd()
+            rc.parse_args()
+            print(sys.argv, '->', rc.run())
+        sys.argv = oldargv
+
+    except Exception as e:
+        print('ryd exception', e)
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/_test/test_issues.py b/_test/test_issues.py
index 5007f60..dd6910b 100644
--- a/_test/test_issues.py
+++ b/_test/test_issues.py
@@ -612,6 +612,23 @@ class TestIssues:
         assert 'c' in yaml_data.keys()
         assert 'c' in yaml_data._ok
 
+    def test_issue_284(self):
+        import ruamel.yaml
+        inp = dedent("""\
+        plain key: in-line value
+        : # Both empty
+        "quoted key":
+        - entry
+        """)
+        yaml = ruamel.yaml.YAML(typ='rt')
+        yaml.version = (1, 2)
+        d = yaml.load(inp)
+        assert d[None] is None
+
+        yaml = ruamel.yaml.YAML(typ='rt')
+        yaml.version = (1, 1)
+        with pytest.raises(ruamel.yaml.parser.ParserError, match='expected <block end>'):
+            d = yaml.load(inp)
 
 #    @pytest.mark.xfail(strict=True, reason='bla bla', raises=AssertionError)
 #    def test_issue_ xxx(self):
diff --git a/parser.py b/parser.py
index a7d082c..0354b6d 100644
--- a/parser.py
+++ b/parser.py
@@ -71,7 +71,7 @@ from __future__ import absolute_import
 # flow_mapping_entry: { ALIAS ANCHOR TAG SCALAR FLOW-SEQUENCE-START
 #                                                    FLOW-MAPPING-START KEY }
 
-# need to have full path, as pkg_resources tries to load parser.py in __init__.py
+# need to have full path with import, as pkg_resources tries to load parser.py in __init__.py
 # only to not do anything with the package afterwards
 # and for Jython too
 
@@ -569,6 +569,9 @@ class Parser(object):
             else:
                 self.state = self.parse_block_mapping_value
                 return self.process_empty_scalar(token.end_mark)
+        if self.resolver.processing_version > (1, 1) and self.scanner.check_token(ValueToken):
+            self.state = self.parse_block_mapping_value
+            return self.process_empty_scalar(self.scanner.peek_token().start_mark)
         if not self.scanner.check_token(BlockEndToken):
             token = self.scanner.peek_token()
             raise ParserError(