Fix extra trailing line break with `|-` block literals

The Emitter.write_literal() function will write a line break after a
block literal value if the block literal didn't end with a line break.
The Scanner.scan_block_scalar() function was keeping track of all newlines
that followed block literals, but when `|-` is used it this was one too many.

The code is changed slightly to avoid a confusing `if chomping is not False`
statement.

2 files changed, 3 insertions, 6 deletions

diff --git a/py/scanner.py b/py/scanner.py
index b497c4b..e3f0548 100644
--- a/py/scanner.py
+++ b/py/scanner.py
@@ -1068,13 +1068,11 @@ class Scanner(object):
         # Process trailing line breaks. The 'chomping' setting determines
         # whether they are included in the value.
         comment = []
-        if chomping is not False:
+        if chomping in [None, True]:
             chunks.append(line_break)
-        else:
-            comment.append(line_break)
         if chomping is True:
             chunks.extend(breaks)
-        else:
+        elif chomping in [None, False]:
             comment.extend(breaks)
 
         # We are done.
diff --git a/test/test_string.py b/test/test_string.py
index eb2e95c..8c08e7d 100644
--- a/test/test_string.py
+++ b/test/test_string.py
@@ -46,8 +46,7 @@ class TestYAML:
               def
 
             """
-        o = dedent(s).rstrip() + '\n'
-        round_trip(s, outp=o, intermediate=dict(a='abc\ndef'))
+        round_trip(s, intermediate=dict(a='abc\ndef'))
 
     def test_preserve_string_keep(self):
             # with pytest.raises(AssertionError) as excinfo: