fixes issue #254 single question mark not dumped with quotes0.15.75

introduced re issue #62 for version 0.15.27
test in ruamel.yaml.data/special/single_indicator.yaml


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7 files changed, 34 insertions, 8 deletions

diff --git a/CHANGES b/CHANGES
index cd4b14f..51b6be3 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,19 @@
+[0, 15, 75]: 2018-10-27
+  - fix issue with single '?' scalar (reported by `Terrance 
+    <https://bitbucket.org/OllieTerrance/>`__)
+  - fix issue with duplicate merge keys (prompted by `answering 
+    <https://stackoverflow.com/a/52852106/1307905>`__ a 
+    `StackOverflow question <https://stackoverflow.com/q/52851168/1307905>`__
+    by `math <https://stackoverflow.com/users/1355634/math>`__)
+
+[0, 15, 75]: 2018-10-27
+  - fix issue with single '?' scalar (reported by `Terrance 
+    <https://bitbucket.org/OllieTerrance/>`__)
+  - fix issue with duplicate merge keys (prompted by `answering 
+    <https://stackoverflow.com/a/52852106/1307905>`__ a 
+    `StackOverflow question <https://stackoverflow.com/q/52851168/1307905>`__
+    by `math <https://stackoverflow.com/users/1355634/math>`__)
+
 [0, 15, 74]: 2018-10-17
   - fix dropping of comment on rt before sequence item that is sequence item
     (reported by `Thorsten Kampe <https://bitbucket.org/thorstenkampe/>`__)
diff --git a/README.rst b/README.rst
index c82ad08..a05eb5f 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:       0.15.74
-:updated:       2018-10-17
+:version:       0.15.75
+:updated:       2018-10-27
 :documentation: http://yaml.readthedocs.io
 :repository:    https://bitbucket.org/ruamel/
 :pypi:          https://pypi.org/project/ruamel.yaml/
@@ -54,6 +54,14 @@ ChangeLog
 
 .. should insert NEXT: at the beginning of line for next key (with empty line)
 
+0.15.75 (2018-10-27):
+  - fix issue with single '?' scalar (reported by `Terrance 
+    <https://bitbucket.org/OllieTerrance/>`__)
+  - fix issue with duplicate merge keys (prompted by `answering 
+    <https://stackoverflow.com/a/52852106/1307905>`__ a 
+    `StackOverflow question <https://stackoverflow.com/q/52851168/1307905>`__
+    by `math <https://stackoverflow.com/users/1355634/math>`__)
+
 0.15.74 (2018-10-17):
   - fix dropping of comment on rt before sequence item that is sequence item
     (reported by `Thorsten Kampe <https://bitbucket.org/thorstenkampe/>`__)
diff --git a/__init__.py b/__init__.py
index 06c70a0..764755b 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, 74),
-    __version__='0.15.74',
+    version_info=(0, 15, 75),
+    __version__='0.15.75',
     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/_static/pypi.svg b/_doc/_static/pypi.svg
index 389f958..2aa33a3 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">0.15.74</text><text x="585" y="140" transform="scale(.1)" textLength="430">0.15.74</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">0.15.75</text><text x="585" y="140" transform="scale(.1)" textLength="430">0.15.75</text></g> </svg>
diff --git a/_test/test_anchor.py b/_test/test_anchor.py
index 4c7a9f2..dec1261 100644
--- a/_test/test_anchor.py
+++ b/_test/test_anchor.py
@@ -493,7 +493,7 @@ class TestDuplicateKeyThroughAnchor:
     def test_duplicate_key_01(self):
         # so issue https://stackoverflow.com/a/52852106/1307905
         from ruamel.yaml import version_info
-        from ruamel.yaml.constructor import DuplicateKeyFutureWarning, DuplicateKeyError
+        from ruamel.yaml.constructor import DuplicateKeyError
 
         s = dedent("""\
         - &name-name
diff --git a/constructor.py b/constructor.py
index 8600c9f..05fbb34 100644
--- a/constructor.py
+++ b/constructor.py
@@ -839,14 +839,14 @@ class Constructor(SafeConstructor):
                     __import__(module_name)
                     # object_name = '.'.join(object_name)
                     break
-                except ImportError as exc:
+                except ImportError:
                     continue
         else:
             module_name = builtins_module
             lobject_name = [name]
         try:
             __import__(module_name)
-        except ImportError as exc:
+        except ImportError:
             raise ConstructorError(
                 'while constructing a Python object',
                 mark,
diff --git a/emitter.py b/emitter.py
index 942eced..c410f2e 100644
--- a/emitter.py
+++ b/emitter.py
@@ -1024,6 +1024,8 @@ class Emitter(object):
                 if ch in u'?:':  # ToDo
                     if self.serializer.use_version == (1, 1):
                         flow_indicators = True
+                    elif len(scalar) == 1:  # single character
+                        flow_indicators = True
                     if followed_by_whitespace:
                         block_indicators = True
                 if ch == u'-' and followed_by_whitespace: