directive-code: do not force linenos value on run

Now that `highlightlang` directive is deprecated [1], the
`linenothreshold` option is to be used via the `highlight` directive.
The `highlight` directive will walk-through literal blocks to apply a
`linenos` value if:

 1) The literal block has not been explicitly configured with the
     `linenos` option.
 2) If there is enough content (when comparing literal block's line
     count to `linenothreshold`) that `linenos` should be explicitly
     enabled or disabled [2].

While the `hightlight` directive should be able to explicitly define if
a literal block needs to enable line numbers, the logic is always
ignored since the code block and literal include directives already
configures `linenos` when checking for line number-specific options on
the node [3][4]. This effectively prevents `linenothreshold` from being
used.

To allow `linenothreshold` to be used in literal blocks, this commit
disables the explicit configuration `linenos` on a literal block
instance when the `CodeBlock` and `LiteralInclude` directives are
processed.

[1]: b35198d8475fe89aaf9a5224a9832fb394e73cca
[2]: https://github.com/sphinx-doc/sphinx/blob/v1.8.1/sphinx/transforms/post_transforms/code.py#L95-L97
[3]: https://github.com/sphinx-doc/sphinx/blob/v1.8.1/sphinx/directives/code.py#L156-L157
[4]: https://github.com/sphinx-doc/sphinx/blob/v1.8.1/sphinx/directives/code.py#L442-L444

Signed-off-by: James Knight <james.d.knight@live.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/sphinx/directives/code.py b/sphinx/directives/code.py
index 9ac704c55..73afac4ba 100644
--- a/sphinx/directives/code.py
+++ b/sphinx/directives/code.py
@@ -154,8 +154,8 @@ class CodeBlock(SphinxDirective):
             code = '\n'.join(lines)
 
         literal = nodes.literal_block(code, code)  # type: nodes.Element
-        literal['linenos'] = 'linenos' in self.options or \
-                             'lineno-start' in self.options
+        if 'linenos' in self.options or 'lineno-start' in self.options:
+            literal['linenos'] = True
         literal['classes'] += self.options.get('class', [])
         if self.arguments:
             # highlight language specified
@@ -451,9 +451,9 @@ class LiteralInclude(SphinxDirective):
                 retnode['language'] = 'udiff'
             elif 'language' in self.options:
                 retnode['language'] = self.options['language']
-            retnode['linenos'] = ('linenos' in self.options or
-                                  'lineno-start' in self.options or
-                                  'lineno-match' in self.options)
+            if ('linenos' in self.options or 'lineno-start' in self.options or
+                    'lineno-match' in self.options):
+                retnode['linenos'] = True
             retnode['classes'] += self.options.get('class', [])
             extra_args = retnode['highlight_args'] = {}
             if 'emphasize-lines' in self.options: