makrup-renderer: fix some cases which could cause lxml errors, skip js flags

rhodecode/lib/markup_renderer.py

@@ -1,455 +1,461 b''
 # -*- coding: utf-8 -*-
 
 # Copyright (C) 2011-2017 RhodeCode GmbH
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License, version 3
 # (only), as published by the Free Software Foundation.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 # This program is dual-licensed. If you wish to learn more about the
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
 
 """
 Renderer for markup languages with ability to parse using rst or markdown
 """
 
 import re
 import os
 import lxml
 import logging
 import urlparse
-import urllib
 
 from mako.lookup import TemplateLookup
 from mako.template import Template as MakoTemplate
 
 from docutils.core import publish_parts
 from docutils.parsers.rst import directives
 import markdown
 
 from rhodecode.lib.markdown_ext import GithubFlavoredMarkdownExtension
 from rhodecode.lib.utils2 import (
     safe_str, safe_unicode, md5_safe, MENTIONS_REGEX)
 
 log = logging.getLogger(__name__)
 
 # default renderer used to generate automated comments
 DEFAULT_COMMENTS_RENDERER = 'rst'
 
 
 def relative_links(html_source, server_path):
-    doc = lxml.html.fromstring(html_source)
+    if not html_source:
+        return html_source
+
+    try:
+        doc = lxml.html.fromstring(html_source)
+    except Exception:
+        return html_source
+
     for el in doc.cssselect('img, video'):
         src = el.attrib['src']
         if src:
             el.attrib['src'] = relative_path(src, server_path)
 
     for el in doc.cssselect('a:not(.gfm)'):
         src = el.attrib['href']
         if src:
             el.attrib['href'] = relative_path(src, server_path)
 
     return lxml.html.tostring(doc)
 
 
 def relative_path(path, request_path, is_repo_file=None):
     """
     relative link support, path is a rel path, and request_path is current
     server path (not absolute)
 
     e.g.
 
     path = '../logo.png'
     request_path= '/repo/files/path/file.md'
     produces: '/repo/files/logo.png'
     """
     # TODO(marcink): unicode/str support ?
     # maybe=> safe_unicode(urllib.quote(safe_str(final_path), '/:'))
 
     def dummy_check(p):
         return True  # assume default is a valid file path
 
     is_repo_file = is_repo_file or dummy_check
     if not path:
         return request_path
 
     path = safe_unicode(path)
     request_path = safe_unicode(request_path)
 
-    if path.startswith((u'data:', u'#', u':')):
+    if path.startswith((u'data:', u'javascript:', u'#', u':')):
         # skip data, anchor, invalid links
         return path
 
     is_absolute = bool(urlparse.urlparse(path).netloc)
     if is_absolute:
         return path
 
     if not request_path:
         return path
 
     if path.startswith(u'/'):
         path = path[1:]
 
     if path.startswith(u'./'):
         path = path[2:]
 
     parts = request_path.split('/')
     # compute how deep we need to traverse the request_path
     depth = 0
 
     if is_repo_file(request_path):
         # if request path is a VALID file, we use a relative path with
         # one level up
         depth += 1
 
     while path.startswith(u'../'):
         depth += 1
         path = path[3:]
 
     if depth > 0:
         parts = parts[:-depth]
 
     parts.append(path)
     final_path = u'/'.join(parts).lstrip(u'/')
 
     return u'/' + final_path
 
 
 class MarkupRenderer(object):
     RESTRUCTUREDTEXT_DISALLOWED_DIRECTIVES = ['include', 'meta', 'raw']
 
     MARKDOWN_PAT = re.compile(r'\.(md|mkdn?|mdown|markdown)$', re.IGNORECASE)
     RST_PAT = re.compile(r'\.re?st$', re.IGNORECASE)
     JUPYTER_PAT = re.compile(r'\.(ipynb)$', re.IGNORECASE)
     PLAIN_PAT = re.compile(r'^readme$', re.IGNORECASE)
 
     extensions = ['codehilite', 'extra', 'def_list', 'sane_lists']
     markdown_renderer = markdown.Markdown(
         extensions, safe_mode=True, enable_attributes=False)
 
     markdown_renderer_flavored = markdown.Markdown(
         extensions + [GithubFlavoredMarkdownExtension()], safe_mode=True,
         enable_attributes=False)
 
     # extension together with weights. Lower is first means we control how
     # extensions are attached to readme names with those.
     PLAIN_EXTS = [
         # prefer no extension
         ('', 0),  # special case that renders READMES names without extension
         ('.text', 2), ('.TEXT', 2),
         ('.txt', 3), ('.TXT', 3)
     ]
 
     RST_EXTS = [
         ('.rst', 1), ('.rest', 1),
         ('.RST', 2), ('.REST', 2)
     ]
 
     MARKDOWN_EXTS = [
         ('.md', 1), ('.MD', 1),
         ('.mkdn', 2), ('.MKDN', 2),
         ('.mdown', 3), ('.MDOWN', 3),
         ('.markdown', 4), ('.MARKDOWN', 4)
     ]
 
     def _detect_renderer(self, source, filename=None):
         """
         runs detection of what renderer should be used for generating html
         from a markup language
 
         filename can be also explicitly a renderer name
 
         :param source:
         :param filename:
         """
 
         if MarkupRenderer.MARKDOWN_PAT.findall(filename):
             detected_renderer = 'markdown'
         elif MarkupRenderer.RST_PAT.findall(filename):
             detected_renderer = 'rst'
         elif MarkupRenderer.JUPYTER_PAT.findall(filename):
             detected_renderer = 'jupyter'
         elif MarkupRenderer.PLAIN_PAT.findall(filename):
             detected_renderer = 'plain'
         else:
             detected_renderer = 'plain'
 
         return getattr(MarkupRenderer, detected_renderer)
 
     @classmethod
     def renderer_from_filename(cls, filename, exclude):
         """
         Detect renderer markdown/rst from filename and optionally use exclude
         list to remove some options. This is mostly used in helpers.
         Returns None when no renderer can be detected.
         """
         def _filter(elements):
             if isinstance(exclude, (list, tuple)):
                 return [x for x in elements if x not in exclude]
             return elements
 
         if filename.endswith(
                 tuple(_filter([x[0] for x in cls.MARKDOWN_EXTS if x[0]]))):
             return 'markdown'
         if filename.endswith(tuple(_filter([x[0] for x in cls.RST_EXTS if x[0]]))):
             return 'rst'
 
         return None
 
     def render(self, source, filename=None):
         """
         Renders a given filename using detected renderer
         it detects renderers based on file extension or mimetype.
         At last it will just do a simple html replacing new lines with <br/>
 
         :param file_name:
         :param source:
         """
 
         renderer = self._detect_renderer(source, filename)
         readme_data = renderer(source)
         return readme_data
 
     @classmethod
     def _flavored_markdown(cls, text):
         """
         Github style flavored markdown
 
         :param text:
         """
 
         # Extract pre blocks.
         extractions = {}
 
         def pre_extraction_callback(matchobj):
             digest = md5_safe(matchobj.group(0))
             extractions[digest] = matchobj.group(0)
             return "{gfm-extraction-%s}" % digest
         pattern = re.compile(r'<pre>.*?</pre>', re.MULTILINE | re.DOTALL)
         text = re.sub(pattern, pre_extraction_callback, text)
 
         # Prevent foo_bar_baz from ending up with an italic word in the middle.
         def italic_callback(matchobj):
             s = matchobj.group(0)
             if list(s).count('_') >= 2:
                 return s.replace('_', r'\_')
             return s
         text = re.sub(r'^(?! {4}|\t)\w+_\w+_\w[\w_]*', italic_callback, text)
 
         # Insert pre block extractions.
         def pre_insert_callback(matchobj):
             return '\n\n' + extractions[matchobj.group(1)]
         text = re.sub(r'\{gfm-extraction-([0-9a-f]{32})\}',
                       pre_insert_callback, text)
 
         return text
 
     @classmethod
     def urlify_text(cls, text):
         url_pat = re.compile(r'(http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]'
                              r'|[!*\(\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+)')
 
         def url_func(match_obj):
             url_full = match_obj.groups()[0]
             return '<a href="%(url)s">%(url)s</a>' % ({'url': url_full})
 
         return url_pat.sub(url_func, text)
 
     @classmethod
     def plain(cls, source, universal_newline=True):
         source = safe_unicode(source)
         if universal_newline:
             newline = '\n'
             source = newline.join(source.splitlines())
 
         source = cls.urlify_text(source)
         return '<br />' + source.replace("\n", '<br />')
 
     @classmethod
     def markdown(cls, source, safe=True, flavored=True, mentions=False):
         # It does not allow to insert inline HTML. In presence of HTML tags, it
         # will replace them instead with [HTML_REMOVED]. This is controlled by
         # the safe_mode=True parameter of the markdown method.
 
         if flavored:
             markdown_renderer = cls.markdown_renderer_flavored
         else:
             markdown_renderer = cls.markdown_renderer
 
         if mentions:
             mention_pat = re.compile(MENTIONS_REGEX)
 
             def wrapp(match_obj):
                 uname = match_obj.groups()[0]
                 return ' **@%(uname)s** ' % {'uname': uname}
             mention_hl = mention_pat.sub(wrapp, source).strip()
             # we extracted mentions render with this using Mentions false
             return cls.markdown(mention_hl, safe=safe, flavored=flavored,
                                 mentions=False)
 
         source = safe_unicode(source)
         try:
             if flavored:
                 source = cls._flavored_markdown(source)
             return markdown_renderer.convert(source)
         except Exception:
             log.exception('Error when rendering Markdown')
             if safe:
                 log.debug('Fallback to render in plain mode')
                 return cls.plain(source)
             else:
                 raise
 
     @classmethod
     def rst(cls, source, safe=True, mentions=False):
         if mentions:
             mention_pat = re.compile(MENTIONS_REGEX)
 
             def wrapp(match_obj):
                 uname = match_obj.groups()[0]
                 return ' **@%(uname)s** ' % {'uname': uname}
             mention_hl = mention_pat.sub(wrapp, source).strip()
             # we extracted mentions render with this using Mentions false
             return cls.rst(mention_hl, safe=safe, mentions=False)
 
         source = safe_unicode(source)
         try:
             docutils_settings = dict(
                 [(alias, None) for alias in
                  cls.RESTRUCTUREDTEXT_DISALLOWED_DIRECTIVES])
 
             docutils_settings.update({'input_encoding': 'unicode',
                                       'report_level': 4})
 
             for k, v in docutils_settings.iteritems():
                 directives.register_directive(k, v)
 
             parts = publish_parts(source=source,
                                   writer_name="html4css1",
                                   settings_overrides=docutils_settings)
 
             return parts['html_title'] + parts["fragment"]
         except Exception:
             log.exception('Error when rendering RST')
             if safe:
                 log.debug('Fallbacking to render in plain mode')
                 return cls.plain(source)
             else:
                 raise
 
     @classmethod
     def jupyter(cls, source, safe=True):
         from rhodecode.lib import helpers
 
         from traitlets.config import Config
         import nbformat
         from nbconvert import HTMLExporter
         from nbconvert.preprocessors import Preprocessor
 
         class CustomHTMLExporter(HTMLExporter):
             def _template_file_default(self):
                 return 'basic'
 
         class Sandbox(Preprocessor):
 
             def preprocess(self, nb, resources):
                 sandbox_text = 'SandBoxed(IPython.core.display.Javascript object)'
                 for cell in nb['cells']:
                     if safe and 'outputs' in cell:
                         for cell_output in cell['outputs']:
                             if 'data' in cell_output:
                                 if 'application/javascript' in cell_output['data']:
                                     cell_output['data']['text/plain'] = sandbox_text
                                     cell_output['data'].pop('application/javascript', None)
                 return nb, resources
 
         def _sanitize_resources(resources):
             """
             Skip/sanitize some of the CSS generated and included in jupyter
             so it doesn't messes up UI so much
             """
 
             # TODO(marcink): probably we should replace this with whole custom
             # CSS set that doesn't screw up, but jupyter generated html has some
             # special markers, so it requires Custom HTML exporter template with
             # _default_template_path_default, to achieve that
 
             # strip the reset CSS
             resources[0] = resources[0][resources[0].find('/*! Source'):]
             return resources
 
         def as_html(notebook):
             conf = Config()
             conf.CustomHTMLExporter.preprocessors = [Sandbox]
             html_exporter = CustomHTMLExporter(config=conf)
 
             (body, resources) = html_exporter.from_notebook_node(notebook)
             header = '<!-- ## IPYTHON NOTEBOOK RENDERING ## -->'
             js = MakoTemplate(r'''
             <!-- Load mathjax -->
                 <!-- MathJax configuration -->
                 <script type="text/x-mathjax-config">
                 MathJax.Hub.Config({
                     jax: ["input/TeX","output/HTML-CSS", "output/PreviewHTML"],
                     extensions: ["tex2jax.js","MathMenu.js","MathZoom.js", "fast-preview.js", "AssistiveMML.js", "[Contrib]/a11y/accessibility-menu.js"],
                     TeX: {
                         extensions: ["AMSmath.js","AMSsymbols.js","noErrors.js","noUndefined.js"]
                     },
                     tex2jax: {
                         inlineMath: [ ['$','$'], ["\\(","\\)"] ],
                         displayMath: [ ['$$','$$'], ["\\[","\\]"] ],
                         processEscapes: true,
                         processEnvironments: true
                     },
                     // Center justify equations in code and markdown cells. Elsewhere
                     // we use CSS to left justify single line equations in code cells.
                     displayAlign: 'center',
                     "HTML-CSS": {
                         styles: {'.MathJax_Display': {"margin": 0}},
                         linebreaks: { automatic: true },
                         availableFonts: ["STIX", "TeX"]
                     },
                     showMathMenu: false
                 });
                 </script>
                 <!-- End of mathjax configuration -->
                 <script src="${h.asset('js/src/math_jax/MathJax.js')}"></script>
             ''').render(h=helpers)
 
             css = '<style>{}</style>'.format(
                 ''.join(_sanitize_resources(resources['inlining']['css'])))
 
             body = '\n'.join([header, css, js, body])
             return body, resources
 
         notebook = nbformat.reads(source, as_version=4)
         (body, resources) = as_html(notebook)
         return body
 
 
 class RstTemplateRenderer(object):
 
     def __init__(self):
         base = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
         rst_template_dirs = [os.path.join(base, 'templates', 'rst_templates')]
         self.template_store = TemplateLookup(
             directories=rst_template_dirs,
             input_encoding='utf-8',
             imports=['from rhodecode.lib import helpers as h'])
 
     def _get_template(self, templatename):
         return self.template_store.get_template(templatename)
 
     def render(self, template_name, **kwargs):
         template = self._get_template(template_name)
         return template.render(**kwargs)