ux: make 'no newline at end of file' message more pronounced in diffs

rhodecode/lib/codeblocks.py

@@ -1,635 +1,641 b''
 # -*- coding: utf-8 -*-
 
 # Copyright (C) 2011-2016  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/
 
 import logging
 import difflib
 from itertools import groupby
 
 from pygments import lex
 from pygments.formatters.html import _get_ttype_class as pygment_token_class
 from rhodecode.lib.helpers import (
     get_lexer_for_filenode, get_lexer_safe, html_escape)
 from rhodecode.lib.utils2 import AttributeDict
 from rhodecode.lib.vcs.nodes import FileNode
 from rhodecode.lib.diff_match_patch import diff_match_patch
 from rhodecode.lib.diffs import LimitedDiffContainer
 from pygments.lexers import get_lexer_by_name
 
 plain_text_lexer = get_lexer_by_name(
     'text', stripall=False, stripnl=False, ensurenl=False)
 
 
 log = logging.getLogger()
 
 
 def filenode_as_lines_tokens(filenode, lexer=None):
     lexer = lexer or get_lexer_for_filenode(filenode)
     log.debug('Generating file node pygment tokens for %s, %s', lexer, filenode)
     tokens = tokenize_string(filenode.content, lexer)
     lines = split_token_stream(tokens, split_string='\n')
     rv = list(lines)
     return rv
 
 
 def tokenize_string(content, lexer):
     """
     Use pygments to tokenize some content based on a lexer
     ensuring all original new lines and whitespace is preserved
     """
 
     lexer.stripall = False
     lexer.stripnl = False
     lexer.ensurenl = False
     for token_type, token_text in lex(content, lexer):
         yield pygment_token_class(token_type), token_text
 
 
 def split_token_stream(tokens, split_string=u'\n'):
     """
     Take a list of (TokenType, text) tuples and split them by a string
 
     >>> split_token_stream([(TEXT, 'some\ntext'), (TEXT, 'more\n')])
     [(TEXT, 'some'), (TEXT, 'text'),
      (TEXT, 'more'), (TEXT, 'text')]
     """
 
     buffer = []
     for token_class, token_text in tokens:
         parts = token_text.split(split_string)
         for part in parts[:-1]:
             buffer.append((token_class, part))
             yield buffer
             buffer = []
 
         buffer.append((token_class, parts[-1]))
 
     if buffer:
         yield buffer
 
 
 def filenode_as_annotated_lines_tokens(filenode):
     """
     Take a file node and return a list of annotations => lines, if no annotation
     is found, it will be None.
 
     eg:
 
     [
         (annotation1, [
             (1, line1_tokens_list),
             (2, line2_tokens_list),
         ]),
         (annotation2, [
             (3, line1_tokens_list),
         ]),
         (None, [
             (4, line1_tokens_list),
         ]),
         (annotation1, [
             (5, line1_tokens_list),
             (6, line2_tokens_list),
         ])
     ]
     """
 
     commit_cache = {} # cache commit_getter lookups
 
     def _get_annotation(commit_id, commit_getter):
         if commit_id not in commit_cache:
             commit_cache[commit_id] = commit_getter()
         return commit_cache[commit_id]
 
     annotation_lookup = {
         line_no: _get_annotation(commit_id, commit_getter)
         for line_no, commit_id, commit_getter, line_content
         in filenode.annotate
     }
 
     annotations_lines = ((annotation_lookup.get(line_no), line_no, tokens)
                           for line_no, tokens
                           in enumerate(filenode_as_lines_tokens(filenode), 1))
 
     grouped_annotations_lines = groupby(annotations_lines, lambda x: x[0])
 
     for annotation, group in grouped_annotations_lines:
         yield (
             annotation, [(line_no, tokens)
                           for (_, line_no, tokens) in group]
         )
 
 
 def render_tokenstream(tokenstream):
     result = []
     for token_class, token_ops_texts in rollup_tokenstream(tokenstream):
 
         if token_class:
             result.append(u'<span class="%s">' % token_class)
         else:
             result.append(u'<span>')
 
         for op_tag, token_text in token_ops_texts:
 
             if op_tag:
                 result.append(u'<%s>' % op_tag)
 
             escaped_text = html_escape(token_text)
 
             # TODO: dan: investigate showing hidden characters like space/nl/tab
             # escaped_text = escaped_text.replace(' ', '<sp> </sp>')
             # escaped_text = escaped_text.replace('\n', '<nl>\n</nl>')
             # escaped_text = escaped_text.replace('\t', '<tab>\t</tab>')
 
             result.append(escaped_text)
 
             if op_tag:
                 result.append(u'</%s>' % op_tag)
 
         result.append(u'</span>')
 
     html = ''.join(result)
     return html
 
 
 def rollup_tokenstream(tokenstream):
     """
     Group a token stream of the format:
 
         ('class', 'op', 'text')
     or
         ('class', 'text')
 
     into
 
         [('class1',
             [('op1', 'text'),
              ('op2', 'text')]),
          ('class2',
             [('op3', 'text')])]
 
     This is used to get the minimal tags necessary when
     rendering to html eg for a token stream ie.
 
     <span class="A"><ins>he</ins>llo</span>
     vs
     <span class="A"><ins>he</ins></span><span class="A">llo</span>
 
     If a 2 tuple is passed in, the output op will be an empty string.
 
     eg:
 
     >>> rollup_tokenstream([('classA', '',      'h'),
                             ('classA', 'del',   'ell'),
                             ('classA', '',      'o'),
                             ('classB', '',      ' '),
                             ('classA', '',      'the'),
                             ('classA', '',      're'),
                             ])
 
     [('classA', [('', 'h'), ('del', 'ell'), ('', 'o')],
      ('classB', [('', ' ')],
      ('classA', [('', 'there')]]
 
     """
     if tokenstream and len(tokenstream[0]) == 2:
         tokenstream = ((t[0], '', t[1]) for t in tokenstream)
 
     result = []
     for token_class, op_list in groupby(tokenstream, lambda t: t[0]):
         ops = []
         for token_op, token_text_list in groupby(op_list, lambda o: o[1]):
             text_buffer = []
             for t_class, t_op, t_text in token_text_list:
                 text_buffer.append(t_text)
             ops.append((token_op, ''.join(text_buffer)))
         result.append((token_class, ops))
     return result
 
 
 def tokens_diff(old_tokens, new_tokens, use_diff_match_patch=True):
     """
     Converts a list of (token_class, token_text) tuples to a list of
     (token_class, token_op, token_text) tuples where token_op is one of
     ('ins', 'del', '')
 
     :param old_tokens: list of (token_class, token_text) tuples of old line
     :param new_tokens: list of (token_class, token_text) tuples of new line
     :param use_diff_match_patch: boolean, will use google's diff match patch
         library which has options to 'smooth' out the character by character
         differences making nicer ins/del blocks
     """
 
     old_tokens_result = []
     new_tokens_result = []
 
     similarity = difflib.SequenceMatcher(None,
         ''.join(token_text for token_class, token_text in old_tokens),
         ''.join(token_text for token_class, token_text in new_tokens)
     ).ratio()
 
     if similarity < 0.6: # return, the blocks are too different
         for token_class, token_text in old_tokens:
             old_tokens_result.append((token_class, '', token_text))
         for token_class, token_text in new_tokens:
             new_tokens_result.append((token_class, '', token_text))
         return old_tokens_result, new_tokens_result, similarity
 
     token_sequence_matcher = difflib.SequenceMatcher(None,
         [x[1] for x in old_tokens],
         [x[1] for x in new_tokens])
 
     for tag, o1, o2, n1, n2 in token_sequence_matcher.get_opcodes():
         # check the differences by token block types first to give a more
         # nicer "block" level replacement vs character diffs
 
         if tag == 'equal':
             for token_class, token_text in old_tokens[o1:o2]:
                 old_tokens_result.append((token_class, '', token_text))
             for token_class, token_text in new_tokens[n1:n2]:
                 new_tokens_result.append((token_class, '', token_text))
         elif tag == 'delete':
             for token_class, token_text in old_tokens[o1:o2]:
                 old_tokens_result.append((token_class, 'del', token_text))
         elif tag == 'insert':
             for token_class, token_text in new_tokens[n1:n2]:
                 new_tokens_result.append((token_class, 'ins', token_text))
         elif tag == 'replace':
             # if same type token blocks must be replaced, do a diff on the
             # characters in the token blocks to show individual changes
 
             old_char_tokens = []
             new_char_tokens = []
             for token_class, token_text in old_tokens[o1:o2]:
                 for char in token_text:
                     old_char_tokens.append((token_class, char))
 
             for token_class, token_text in new_tokens[n1:n2]:
                 for char in token_text:
                     new_char_tokens.append((token_class, char))
 
             old_string = ''.join([token_text for
                 token_class, token_text in old_char_tokens])
             new_string = ''.join([token_text for
                 token_class, token_text in new_char_tokens])
 
             char_sequence = difflib.SequenceMatcher(
                 None, old_string, new_string)
             copcodes = char_sequence.get_opcodes()
             obuffer, nbuffer = [], []
 
             if use_diff_match_patch:
                 dmp = diff_match_patch()
                 dmp.Diff_EditCost = 11 # TODO: dan: extract this to a setting
                 reps = dmp.diff_main(old_string, new_string)
                 dmp.diff_cleanupEfficiency(reps)
 
                 a, b = 0, 0
                 for op, rep in reps:
                     l = len(rep)
                     if op == 0:
                         for i, c in enumerate(rep):
                             obuffer.append((old_char_tokens[a+i][0], '', c))
                             nbuffer.append((new_char_tokens[b+i][0], '', c))
                         a += l
                         b += l
                     elif op == -1:
                         for i, c in enumerate(rep):
                             obuffer.append((old_char_tokens[a+i][0], 'del', c))
                         a += l
                     elif op == 1:
                         for i, c in enumerate(rep):
                             nbuffer.append((new_char_tokens[b+i][0], 'ins', c))
                         b += l
             else:
                 for ctag, co1, co2, cn1, cn2 in copcodes:
                     if ctag == 'equal':
                         for token_class, token_text in old_char_tokens[co1:co2]:
                             obuffer.append((token_class, '', token_text))
                         for token_class, token_text in new_char_tokens[cn1:cn2]:
                             nbuffer.append((token_class, '', token_text))
                     elif ctag == 'delete':
                         for token_class, token_text in old_char_tokens[co1:co2]:
                             obuffer.append((token_class, 'del', token_text))
                     elif ctag == 'insert':
                         for token_class, token_text in new_char_tokens[cn1:cn2]:
                             nbuffer.append((token_class, 'ins', token_text))
                     elif ctag == 'replace':
                         for token_class, token_text in old_char_tokens[co1:co2]:
                             obuffer.append((token_class, 'del', token_text))
                         for token_class, token_text in new_char_tokens[cn1:cn2]:
                             nbuffer.append((token_class, 'ins', token_text))
 
             old_tokens_result.extend(obuffer)
             new_tokens_result.extend(nbuffer)
 
     return old_tokens_result, new_tokens_result, similarity
 
 
 class DiffSet(object):
     """
     An object for parsing the diff result from diffs.DiffProcessor and
     adding highlighting, side by side/unified renderings and line diffs
     """
 
     HL_REAL = 'REAL' # highlights using original file, slow
     HL_FAST = 'FAST' # highlights using just the line, fast but not correct
                      # in the case of multiline code
     HL_NONE = 'NONE' # no highlighting, fastest
 
     def __init__(self, highlight_mode=HL_REAL,
                  source_node_getter=lambda filename: None,
                  target_node_getter=lambda filename: None,
                  source_nodes=None, target_nodes=None,
                  max_file_size_limit=150 * 1024, # files over this size will
                                                  # use fast highlighting
                  ):
 
         self.highlight_mode = highlight_mode
         self.highlighted_filenodes = {}
         self.source_node_getter = source_node_getter
         self.target_node_getter = target_node_getter
         self.source_nodes = source_nodes or {}
         self.target_nodes = target_nodes or {}
 
 
         self.max_file_size_limit = max_file_size_limit
 
     def render_patchset(self, patchset, source_ref=None, target_ref=None):
         diffset = AttributeDict(dict(
             lines_added=0,
             lines_deleted=0,
             changed_files=0,
             files=[],
             limited_diff=isinstance(patchset, LimitedDiffContainer),
             source_ref=source_ref,
             target_ref=target_ref,
         ))
         for patch in patchset:
             filediff = self.render_patch(patch)
             filediff.diffset = diffset
             diffset.files.append(filediff)
             diffset.changed_files += 1
             if not patch['stats']['binary']:
                 diffset.lines_added += patch['stats']['added']
                 diffset.lines_deleted += patch['stats']['deleted']
 
         return diffset
 
     _lexer_cache = {}
     def _get_lexer_for_filename(self, filename):
         # cached because we might need to call it twice for source/target
         if filename not in self._lexer_cache:
             self._lexer_cache[filename] = get_lexer_safe(filepath=filename)
         return self._lexer_cache[filename]
 
     def render_patch(self, patch):
         log.debug('rendering diff for %r' % patch['filename'])
 
         source_filename = patch['original_filename']
         target_filename = patch['filename']
 
         source_lexer = plain_text_lexer
         target_lexer = plain_text_lexer
 
         if not patch['stats']['binary']:
             if self.highlight_mode == self.HL_REAL:
                 if (source_filename and patch['operation'] in ('D', 'M')
                     and source_filename not in self.source_nodes):
                         self.source_nodes[source_filename] = (
                             self.source_node_getter(source_filename))
 
                 if (target_filename and patch['operation'] in ('A', 'M')
                     and target_filename not in self.target_nodes):
                         self.target_nodes[target_filename] = (
                             self.target_node_getter(target_filename))
 
             elif self.highlight_mode == self.HL_FAST:
                 source_lexer = self._get_lexer_for_filename(source_filename)
                 target_lexer = self._get_lexer_for_filename(target_filename)
 
         source_file = self.source_nodes.get(source_filename, source_filename)
         target_file = self.target_nodes.get(target_filename, target_filename)
 
         source_filenode, target_filenode = None, None
 
         # TODO: dan: FileNode.lexer works on the content of the file - which
         # can be slow - issue #4289 explains a lexer clean up - which once
         # done can allow caching a lexer for a filenode to avoid the file lookup
         if isinstance(source_file, FileNode):
             source_filenode = source_file
             source_lexer = source_file.lexer
         if isinstance(target_file, FileNode):
             target_filenode = target_file
             target_lexer = target_file.lexer
 
         source_file_path, target_file_path = None, None
 
         if source_filename != '/dev/null':
             source_file_path = source_filename
         if target_filename != '/dev/null':
             target_file_path = target_filename
 
         source_file_type = source_lexer.name
         target_file_type = target_lexer.name
 
         op_hunks = patch['chunks'][0]
         hunks = patch['chunks'][1:]
 
         filediff = AttributeDict({
             'source_file_path': source_file_path,
             'target_file_path': target_file_path,
             'source_filenode': source_filenode,
             'target_filenode': target_filenode,
             'hunks': [],
             'source_file_type': target_file_type,
             'target_file_type': source_file_type,
             'patch': patch,
             'source_mode': patch['stats']['old_mode'],
             'target_mode': patch['stats']['new_mode'],
             'limited_diff': isinstance(patch, LimitedDiffContainer),
             'diffset': self,
         })
 
         for hunk in hunks:
             hunkbit = self.parse_hunk(hunk, source_file, target_file)
             hunkbit.filediff = filediff
             filediff.hunks.append(hunkbit)
         return filediff
 
     def parse_hunk(self, hunk, source_file, target_file):
         result = AttributeDict(dict(
             source_start=hunk['source_start'],
             source_length=hunk['source_length'],
             target_start=hunk['target_start'],
             target_length=hunk['target_length'],
             section_header=hunk['section_header'],
             lines=[],
         ))
         before, after = [], []
 
         for line in hunk['lines']:
             if line['action'] == 'unmod':
                 result.lines.extend(
                     self.parse_lines(before, after, source_file, target_file))
                 after.append(line)
                 before.append(line)
             elif line['action'] == 'add':
                 after.append(line)
             elif line['action'] == 'del':
                 before.append(line)
-            elif line['action'] == 'context-old':
+            elif line['action'] == 'old-no-nl':
                 before.append(line)
-            elif line['action'] == 'context-new':
+            elif line['action'] == 'new-no-nl':
                 after.append(line)
 
         result.lines.extend(
             self.parse_lines(before, after, source_file, target_file))
         result.unified = self.as_unified(result.lines)
         result.sideside = result.lines
         return result
 
     def parse_lines(self, before_lines, after_lines, source_file, target_file):
         # TODO: dan: investigate doing the diff comparison and fast highlighting
         # on the entire before and after buffered block lines rather than by
         # line, this means we can get better 'fast' highlighting if the context
         # allows it - eg.
         # line 4: """
         # line 5: this gets highlighted as a string
         # line 6: """
 
         lines = []
         while before_lines or after_lines:
             before, after = None, None
             before_tokens, after_tokens = None, None
 
             if before_lines:
                 before = before_lines.pop(0)
             if after_lines:
                 after = after_lines.pop(0)
 
             original = AttributeDict()
             modified = AttributeDict()
 
             if before:
+                if before['action'] == 'old-no-nl':
+                    before_tokens = [('nonl', before['line'])]
+                else:
                 before_tokens = self.get_line_tokens(
                     line_text=before['line'], line_number=before['old_lineno'],
                     file=source_file)
                 original.lineno = before['old_lineno']
                 original.content = before['line']
                 original.action = self.action_to_op(before['action'])
 
             if after:
+                if after['action'] == 'new-no-nl':
+                    after_tokens = [('nonl', after['line'])]
+                else:
                 after_tokens = self.get_line_tokens(
                     line_text=after['line'], line_number=after['new_lineno'],
                     file=target_file)
                 modified.lineno = after['new_lineno']
                 modified.content = after['line']
                 modified.action = self.action_to_op(after['action'])
 
-
             # diff the lines
             if before_tokens and after_tokens:
-                o_tokens, m_tokens, similarity = tokens_diff(before_tokens, after_tokens)
+                o_tokens, m_tokens, similarity = tokens_diff(
+                    before_tokens, after_tokens)
                 original.content = render_tokenstream(o_tokens)
                 modified.content = render_tokenstream(m_tokens)
             elif before_tokens:
                 original.content = render_tokenstream(
                     [(x[0], '', x[1]) for x in before_tokens])
             elif after_tokens:
                 modified.content = render_tokenstream(
                     [(x[0], '', x[1]) for x in after_tokens])
 
             lines.append(AttributeDict({
                 'original': original,
                 'modified': modified,
             }))
 
         return lines
 
     def get_line_tokens(self, line_text, line_number, file=None):
         filenode = None
         filename = None
 
         if isinstance(file, basestring):
             filename = file
         elif isinstance(file, FileNode):
             filenode = file
             filename = file.unicode_path
 
         if self.highlight_mode == self.HL_REAL and filenode:
             if line_number and file.size < self.max_file_size_limit:
                 return self.get_tokenized_filenode_line(file, line_number)
 
         if self.highlight_mode in (self.HL_REAL, self.HL_FAST) and filename:
             lexer = self._get_lexer_for_filename(filename)
             return list(tokenize_string(line_text, lexer))
 
         return list(tokenize_string(line_text, plain_text_lexer))
 
     def get_tokenized_filenode_line(self, filenode, line_number):
 
         if filenode not in self.highlighted_filenodes:
             tokenized_lines = filenode_as_lines_tokens(filenode, filenode.lexer)
             self.highlighted_filenodes[filenode] = tokenized_lines
         return self.highlighted_filenodes[filenode][line_number - 1]
 
     def action_to_op(self, action):
         return {
             'add': '+',
             'del': '-',
             'unmod': ' ',
-            'context-old': ' ',
-            'context-new': ' ',
+            'old-no-nl': ' ',
+            'new-no-nl': ' ',
         }.get(action, action)
 
     def as_unified(self, lines):
         """ Return a generator that yields the lines of a diff in unified order """
         def generator():
             buf = []
             for line in lines:
 
                 if buf and not line.original or line.original.action == ' ':
                     for b in buf:
                         yield b
                     buf = []
 
                 if line.original:
                     if line.original.action == ' ':
                         yield (line.original.lineno, line.modified.lineno,
                                line.original.action, line.original.content)
                         continue
 
                     if line.original.action == '-':
                         yield (line.original.lineno, None,
                                line.original.action, line.original.content)
 
                     if line.modified.action == '+':
                         buf.append((
                             None, line.modified.lineno,
                             line.modified.action, line.modified.content))
                         continue
 
                 if line.modified:
                     yield (None, line.modified.lineno,
                            line.modified.action, line.modified.content)
 
             for b in buf:
                 yield b
 
         return generator()

rhodecode/lib/diffs.py

@@ -1,1161 +1,1161 b''
 # -*- coding: utf-8 -*-
 
 # Copyright (C) 2011-2016  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/
 
 
 """
 Set of diffing helpers, previously part of vcs
 """
 
 import collections
 import re
 import difflib
 import logging
 
 from itertools import tee, imap
 
 from pylons.i18n.translation import _
 
 from rhodecode.lib.vcs.exceptions import VCSError
 from rhodecode.lib.vcs.nodes import FileNode, SubModuleNode
 from rhodecode.lib.vcs.backends.base import EmptyCommit
 from rhodecode.lib.helpers import escape
 from rhodecode.lib.utils2 import safe_unicode
 
 log = logging.getLogger(__name__)
 
 # define max context, a file with more than this numbers of lines is unusable
 # in browser anyway
 MAX_CONTEXT = 1024 * 1014
 
 
 class OPS(object):
     ADD = 'A'
     MOD = 'M'
     DEL = 'D'
 
 
 def wrap_to_table(str_):
     return '''<table class="code-difftable">
                 <tr class="line no-comment">
                 <td class="add-comment-line tooltip" title="%s"><span class="add-comment-content"></span></td>
                 <td></td>
                 <td class="lineno new"></td>
                 <td class="code no-comment"><pre>%s</pre></td>
                 </tr>
               </table>''' % (_('Click to comment'), str_)
 
 
 def wrapped_diff(filenode_old, filenode_new, diff_limit=None, file_limit=None,
                  show_full_diff=False, ignore_whitespace=True, line_context=3,
                  enable_comments=False):
     """
     returns a wrapped diff into a table, checks for cut_off_limit for file and
     whole diff and presents proper message
     """
 
     if filenode_old is None:
         filenode_old = FileNode(filenode_new.path, '', EmptyCommit())
 
     if filenode_old.is_binary or filenode_new.is_binary:
         diff = wrap_to_table(_('Binary file'))
         stats = None
         size = 0
         data = None
 
     elif diff_limit != -1 and (diff_limit is None or
         (filenode_old.size < diff_limit and filenode_new.size < diff_limit)):
 
         f_gitdiff = get_gitdiff(filenode_old, filenode_new,
                                 ignore_whitespace=ignore_whitespace,
                                 context=line_context)
         diff_processor = DiffProcessor(
             f_gitdiff, format='gitdiff', diff_limit=diff_limit,
             file_limit=file_limit, show_full_diff=show_full_diff)
         _parsed = diff_processor.prepare()
 
         diff = diff_processor.as_html(enable_comments=enable_comments)
         stats = _parsed[0]['stats'] if _parsed else None
         size = len(diff or '')
         data = _parsed[0] if _parsed else None
     else:
         diff = wrap_to_table(_('Changeset was too big and was cut off, use '
                                'diff menu to display this diff'))
         stats = None
         size = 0
         data = None
     if not diff:
         submodules = filter(lambda o: isinstance(o, SubModuleNode),
                             [filenode_new, filenode_old])
         if submodules:
             diff = wrap_to_table(escape('Submodule %r' % submodules[0]))
         else:
             diff = wrap_to_table(_('No changes detected'))
 
     cs1 = filenode_old.commit.raw_id
     cs2 = filenode_new.commit.raw_id
 
     return size, cs1, cs2, diff, stats, data
 
 
 def get_gitdiff(filenode_old, filenode_new, ignore_whitespace=True, context=3):
     """
     Returns git style diff between given ``filenode_old`` and ``filenode_new``.
 
     :param ignore_whitespace: ignore whitespaces in diff
     """
     # make sure we pass in default context
     context = context or 3
     # protect against IntOverflow when passing HUGE context
     if context > MAX_CONTEXT:
         context = MAX_CONTEXT
 
     submodules = filter(lambda o: isinstance(o, SubModuleNode),
                         [filenode_new, filenode_old])
     if submodules:
         return ''
 
     for filenode in (filenode_old, filenode_new):
         if not isinstance(filenode, FileNode):
             raise VCSError(
                 "Given object should be FileNode object, not %s"
                 % filenode.__class__)
 
     repo = filenode_new.commit.repository
     old_commit = filenode_old.commit or repo.EMPTY_COMMIT
     new_commit = filenode_new.commit
 
     vcs_gitdiff = repo.get_diff(
         old_commit, new_commit, filenode_new.path,
         ignore_whitespace, context, path1=filenode_old.path)
     return vcs_gitdiff
 
 NEW_FILENODE = 1
 DEL_FILENODE = 2
 MOD_FILENODE = 3
 RENAMED_FILENODE = 4
 COPIED_FILENODE = 5
 CHMOD_FILENODE = 6
 BIN_FILENODE = 7
 
 
 class LimitedDiffContainer(object):
 
     def __init__(self, diff_limit, cur_diff_size, diff):
         self.diff = diff
         self.diff_limit = diff_limit
         self.cur_diff_size = cur_diff_size
 
     def __getitem__(self, key):
         return self.diff.__getitem__(key)
 
     def __iter__(self):
         for l in self.diff:
             yield l
 
 
 class Action(object):
     """
     Contains constants for the action value of the lines in a parsed diff.
     """
 
     ADD = 'add'
     DELETE = 'del'
     UNMODIFIED = 'unmod'
 
     CONTEXT = 'context'
-    CONTEXT_OLD = 'context-old'
-    CONTEXT_NEW = 'context-new'
+    OLD_NO_NL = 'old-no-nl'
+    NEW_NO_NL = 'new-no-nl'
 
 
 class DiffProcessor(object):
     """
     Give it a unified or git diff and it returns a list of the files that were
     mentioned in the diff together with a dict of meta information that
     can be used to render it in a HTML template.
 
     .. note:: Unicode handling
 
        The original diffs are a byte sequence and can contain filenames
        in mixed encodings. This class generally returns `unicode` objects
        since the result is intended for presentation to the user.
 
     """
     _chunk_re = re.compile(r'^@@ -(\d+)(?:,(\d+))? \+(\d+)(?:,(\d+))? @@(.*)')
     _newline_marker = re.compile(r'^\\ No newline at end of file')
 
     # used for inline highlighter word split
     _token_re = re.compile(r'()(&gt;|&lt;|&amp;|\W+?)')
 
     def __init__(self, diff, format='gitdiff', diff_limit=None,
                  file_limit=None, show_full_diff=True):
         """
         :param diff: A `Diff` object representing a diff from a vcs backend
         :param format: format of diff passed, `udiff` or `gitdiff`
         :param diff_limit: define the size of diff that is considered "big"
             based on that parameter cut off will be triggered, set to None
             to show full diff
         """
         self._diff = diff
         self._format = format
         self.adds = 0
         self.removes = 0
         # calculate diff size
         self.diff_limit = diff_limit
         self.file_limit = file_limit
         self.show_full_diff = show_full_diff
         self.cur_diff_size = 0
         self.parsed = False
         self.parsed_diff = []
 
         if format == 'gitdiff':
             self.differ = self._highlight_line_difflib
             self._parser = self._parse_gitdiff
         else:
             self.differ = self._highlight_line_udiff
             self._parser = self._new_parse_gitdiff
 
     def _copy_iterator(self):
         """
         make a fresh copy of generator, we should not iterate thru
         an original as it's needed for repeating operations on
         this instance of DiffProcessor
         """
         self.__udiff, iterator_copy = tee(self.__udiff)
         return iterator_copy
 
     def _escaper(self, string):
         """
         Escaper for diff escapes special chars and checks the diff limit
 
         :param string:
         """
 
         self.cur_diff_size += len(string)
 
         if not self.show_full_diff and (self.cur_diff_size > self.diff_limit):
             raise DiffLimitExceeded('Diff Limit Exceeded')
 
         return safe_unicode(string)\
             .replace('&', '&amp;')\
             .replace('<', '&lt;')\
             .replace('>', '&gt;')
 
     def _line_counter(self, l):
         """
         Checks each line and bumps total adds/removes for this diff
 
         :param l:
         """
         if l.startswith('+') and not l.startswith('+++'):
             self.adds += 1
         elif l.startswith('-') and not l.startswith('---'):
             self.removes += 1
         return safe_unicode(l)
 
     def _highlight_line_difflib(self, line, next_):
         """
         Highlight inline changes in both lines.
         """
 
         if line['action'] == Action.DELETE:
             old, new = line, next_
         else:
             old, new = next_, line
 
         oldwords = self._token_re.split(old['line'])
         newwords = self._token_re.split(new['line'])
         sequence = difflib.SequenceMatcher(None, oldwords, newwords)
 
         oldfragments, newfragments = [], []
         for tag, i1, i2, j1, j2 in sequence.get_opcodes():
             oldfrag = ''.join(oldwords[i1:i2])
             newfrag = ''.join(newwords[j1:j2])
             if tag != 'equal':
                 if oldfrag:
                     oldfrag = '<del>%s</del>' % oldfrag
                 if newfrag:
                     newfrag = '<ins>%s</ins>' % newfrag
             oldfragments.append(oldfrag)
             newfragments.append(newfrag)
 
         old['line'] = "".join(oldfragments)
         new['line'] = "".join(newfragments)
 
     def _highlight_line_udiff(self, line, next_):
         """
         Highlight inline changes in both lines.
         """
         start = 0
         limit = min(len(line['line']), len(next_['line']))
         while start < limit and line['line'][start] == next_['line'][start]:
             start += 1
         end = -1
         limit -= start
         while -end <= limit and line['line'][end] == next_['line'][end]:
             end -= 1
         end += 1
         if start or end:
             def do(l):
                 last = end + len(l['line'])
                 if l['action'] == Action.ADD:
                     tag = 'ins'
                 else:
                     tag = 'del'
                 l['line'] = '%s<%s>%s</%s>%s' % (
                     l['line'][:start],
                     tag,
                     l['line'][start:last],
                     tag,
                     l['line'][last:]
                 )
             do(line)
             do(next_)
 
     def _clean_line(self, line, command):
         if command in ['+', '-', ' ']:
             # only modify the line if it's actually a diff thing
             line = line[1:]
         return line
 
     def _parse_gitdiff(self, inline_diff=True):
         _files = []
         diff_container = lambda arg: arg
 
         for chunk in self._diff.chunks():
             head = chunk.header
 
             diff = imap(self._escaper, chunk.diff.splitlines(1))
             raw_diff = chunk.raw
             limited_diff = False
             exceeds_limit = False
 
             op = None
             stats = {
                 'added': 0,
                 'deleted': 0,
                 'binary': False,
                 'ops': {},
             }
 
             if head['deleted_file_mode']:
                 op = OPS.DEL
                 stats['binary'] = True
                 stats['ops'][DEL_FILENODE] = 'deleted file'
 
             elif head['new_file_mode']:
                 op = OPS.ADD
                 stats['binary'] = True
                 stats['ops'][NEW_FILENODE] = 'new file %s' % head['new_file_mode']
             else:  # modify operation, can be copy, rename or chmod
 
                 # CHMOD
                 if head['new_mode'] and head['old_mode']:
                     op = OPS.MOD
                     stats['binary'] = True
                     stats['ops'][CHMOD_FILENODE] = (
                         'modified file chmod %s => %s' % (
                             head['old_mode'], head['new_mode']))
                 # RENAME
                 if head['rename_from'] != head['rename_to']:
                     op = OPS.MOD
                     stats['binary'] = True
                     stats['ops'][RENAMED_FILENODE] = (
                         'file renamed from %s to %s' % (
                             head['rename_from'], head['rename_to']))
                 # COPY
                 if head.get('copy_from') and head.get('copy_to'):
                     op = OPS.MOD
                     stats['binary'] = True
                     stats['ops'][COPIED_FILENODE] = (
                         'file copied from %s to %s' % (
                             head['copy_from'], head['copy_to']))
 
                 # If our new parsed headers didn't match anything fallback to
                 # old style detection
                 if op is None:
                     if not head['a_file'] and head['b_file']:
                         op = OPS.ADD
                         stats['binary'] = True
                         stats['ops'][NEW_FILENODE] = 'new file'
 
                     elif head['a_file'] and not head['b_file']:
                         op = OPS.DEL
                         stats['binary'] = True
                         stats['ops'][DEL_FILENODE] = 'deleted file'
 
                 # it's not ADD not DELETE
                 if op is None:
                     op = OPS.MOD
                     stats['binary'] = True
                     stats['ops'][MOD_FILENODE] = 'modified file'
 
             # a real non-binary diff
             if head['a_file'] or head['b_file']:
                 try:
                     raw_diff, chunks, _stats = self._parse_lines(diff)
                     stats['binary'] = False
                     stats['added'] = _stats[0]
                     stats['deleted'] = _stats[1]
                     # explicit mark that it's a modified file
                     if op == OPS.MOD:
                         stats['ops'][MOD_FILENODE] = 'modified file'
                     exceeds_limit = len(raw_diff) > self.file_limit
 
                     # changed from _escaper function so we validate size of
                     # each file instead of the whole diff
                     # diff will hide big files but still show small ones
                     # from my tests, big files are fairly safe to be parsed
                     # but the browser is the bottleneck
                     if not self.show_full_diff and exceeds_limit:
                         raise DiffLimitExceeded('File Limit Exceeded')
 
                 except DiffLimitExceeded:
                     diff_container = lambda _diff: \
                         LimitedDiffContainer(
                             self.diff_limit, self.cur_diff_size, _diff)
 
                     exceeds_limit = len(raw_diff) > self.file_limit
                     limited_diff = True
                     chunks = []
 
             else:  # GIT format binary patch, or possibly empty diff
                 if head['bin_patch']:
                     # we have operation already extracted, but we mark simply
                     # it's a diff we wont show for binary files
                     stats['ops'][BIN_FILENODE] = 'binary diff hidden'
                 chunks = []
 
             if chunks and not self.show_full_diff and op == OPS.DEL:
                 # if not full diff mode show deleted file contents
                 # TODO: anderson: if the view is not too big, there is no way
                 # to see the content of the file
                 chunks = []
 
             chunks.insert(0, [{
                                   'old_lineno': '',
                                   'new_lineno': '',
                                   'action': Action.CONTEXT,
                                   'line': msg,
                               } for _op, msg in stats['ops'].iteritems()
                               if _op not in [MOD_FILENODE]])
 
             _files.append({
                 'filename': safe_unicode(head['b_path']),
                 'old_revision': head['a_blob_id'],
                 'new_revision': head['b_blob_id'],
                 'chunks': chunks,
                 'raw_diff': safe_unicode(raw_diff),
                 'operation': op,
                 'stats': stats,
                 'exceeds_limit': exceeds_limit,
                 'is_limited_diff': limited_diff,
             })
 
         sorter = lambda info: {OPS.ADD: 0, OPS.MOD: 1,
                                OPS.DEL: 2}.get(info['operation'])
 
         if not inline_diff:
             return diff_container(sorted(_files, key=sorter))
 
         # highlight inline changes
         for diff_data in _files:
             for chunk in diff_data['chunks']:
                 lineiter = iter(chunk)
                 try:
                     while 1:
                         line = lineiter.next()
                         if line['action'] not in (
                                 Action.UNMODIFIED, Action.CONTEXT):
                             nextline = lineiter.next()
                             if nextline['action'] in ['unmod', 'context'] or \
                                nextline['action'] == line['action']:
                                 continue
                             self.differ(line, nextline)
                 except StopIteration:
                     pass
 
         return diff_container(sorted(_files, key=sorter))
 
 
     # FIXME: NEWDIFFS: dan: this replaces the old _escaper function
     def _process_line(self, string):
         """
         Process a diff line, checks the diff limit
 
         :param string:
         """
 
         self.cur_diff_size += len(string)
 
         if not self.show_full_diff and (self.cur_diff_size > self.diff_limit):
             raise DiffLimitExceeded('Diff Limit Exceeded')
 
         return safe_unicode(string)
 
     # FIXME: NEWDIFFS: dan: this replaces _parse_gitdiff
     def _new_parse_gitdiff(self, inline_diff=True):
         _files = []
         diff_container = lambda arg: arg
         for chunk in self._diff.chunks():
             head = chunk.header
             log.debug('parsing diff %r' % head)
 
             diff = imap(self._process_line, chunk.diff.splitlines(1))
             raw_diff = chunk.raw
             limited_diff = False
             exceeds_limit = False
             # if 'empty_file_to_modify_and_rename' in head['a_path']:
             #     1/0
             op = None
             stats = {
                 'added': 0,
                 'deleted': 0,
                 'binary': False,
                 'old_mode': None,
                 'new_mode': None,
                 'ops': {},
             }
             if head['old_mode']:
                 stats['old_mode'] = head['old_mode']
             if head['new_mode']:
                 stats['new_mode'] = head['new_mode']
             if head['b_mode']:
                 stats['new_mode'] = head['b_mode']
 
             if head['deleted_file_mode']:
                 op = OPS.DEL
                 stats['binary'] = True
                 stats['ops'][DEL_FILENODE] = 'deleted file'
 
             elif head['new_file_mode']:
                 op = OPS.ADD
                 stats['binary'] = True
                 stats['old_mode'] = None
                 stats['new_mode'] = head['new_file_mode']
                 stats['ops'][NEW_FILENODE] = 'new file %s' % head['new_file_mode']
             else:  # modify operation, can be copy, rename or chmod
 
                 # CHMOD
                 if head['new_mode'] and head['old_mode']:
                     op = OPS.MOD
                     stats['binary'] = True
                     stats['ops'][CHMOD_FILENODE] = (
                         'modified file chmod %s => %s' % (
                             head['old_mode'], head['new_mode']))
 
                 # RENAME
                 if head['rename_from'] != head['rename_to']:
                     op = OPS.MOD
                     stats['binary'] = True
                     stats['renamed'] = (head['rename_from'], head['rename_to'])
                     stats['ops'][RENAMED_FILENODE] = (
                         'file renamed from %s to %s' % (
                             head['rename_from'], head['rename_to']))
                 # COPY
                 if head.get('copy_from') and head.get('copy_to'):
                     op = OPS.MOD
                     stats['binary'] = True
                     stats['copied'] = (head['copy_from'], head['copy_to'])
                     stats['ops'][COPIED_FILENODE] = (
                         'file copied from %s to %s' % (
                             head['copy_from'], head['copy_to']))
 
                 # If our new parsed headers didn't match anything fallback to
                 # old style detection
                 if op is None:
                     if not head['a_file'] and head['b_file']:
                         op = OPS.ADD
                         stats['binary'] = True
                         stats['new_file'] = True
                         stats['ops'][NEW_FILENODE] = 'new file'
 
                     elif head['a_file'] and not head['b_file']:
                         op = OPS.DEL
                         stats['binary'] = True
                         stats['ops'][DEL_FILENODE] = 'deleted file'
 
                 # it's not ADD not DELETE
                 if op is None:
                     op = OPS.MOD
                     stats['binary'] = True
                     stats['ops'][MOD_FILENODE] = 'modified file'
 
             # a real non-binary diff
             if head['a_file'] or head['b_file']:
                 try:
                     raw_diff, chunks, _stats = self._new_parse_lines(diff)
                     stats['binary'] = False
                     stats['added'] = _stats[0]
                     stats['deleted'] = _stats[1]
                     # explicit mark that it's a modified file
                     if op == OPS.MOD:
                         stats['ops'][MOD_FILENODE] = 'modified file'
                     exceeds_limit = len(raw_diff) > self.file_limit
 
                     # changed from _escaper function so we validate size of
                     # each file instead of the whole diff
                     # diff will hide big files but still show small ones
                     # from my tests, big files are fairly safe to be parsed
                     # but the browser is the bottleneck
                     if not self.show_full_diff and exceeds_limit:
                         raise DiffLimitExceeded('File Limit Exceeded')
 
                 except DiffLimitExceeded:
                     diff_container = lambda _diff: \
                         LimitedDiffContainer(
                             self.diff_limit, self.cur_diff_size, _diff)
 
                     exceeds_limit = len(raw_diff) > self.file_limit
                     limited_diff = True
                     chunks = []
 
             else:  # GIT format binary patch, or possibly empty diff
                 if head['bin_patch']:
                     # we have operation already extracted, but we mark simply
                     # it's a diff we wont show for binary files
                     stats['ops'][BIN_FILENODE] = 'binary diff hidden'
                 chunks = []
 
             if chunks and not self.show_full_diff and op == OPS.DEL:
                 # if not full diff mode show deleted file contents
                 # TODO: anderson: if the view is not too big, there is no way
                 # to see the content of the file
                 chunks = []
 
             chunks.insert(0, [{
                                   'old_lineno': '',
                                   'new_lineno': '',
                                   'action': Action.CONTEXT,
                                   'line': msg,
                               } for _op, msg in stats['ops'].iteritems()
                               if _op not in [MOD_FILENODE]])
 
             original_filename = safe_unicode(head['a_path'])
             _files.append({
                 'original_filename': original_filename,
                 'filename': safe_unicode(head['b_path']),
                 'old_revision': head['a_blob_id'],
                 'new_revision': head['b_blob_id'],
                 'chunks': chunks,
                 'raw_diff': safe_unicode(raw_diff),
                 'operation': op,
                 'stats': stats,
                 'exceeds_limit': exceeds_limit,
                 'is_limited_diff': limited_diff,
             })
 
 
         sorter = lambda info: {OPS.ADD: 0, OPS.MOD: 1,
                                OPS.DEL: 2}.get(info['operation'])
 
         return diff_container(sorted(_files, key=sorter))
 
     # FIXME: NEWDIFFS: dan: this gets replaced by _new_parse_lines
     def _parse_lines(self, diff):
         """
         Parse the diff an return data for the template.
         """
 
         lineiter = iter(diff)
         stats = [0, 0]
         chunks = []
         raw_diff = []
 
         try:
             line = lineiter.next()
 
             while line:
                 raw_diff.append(line)
                 lines = []
                 chunks.append(lines)
 
                 match = self._chunk_re.match(line)
 
                 if not match:
                     break
 
                 gr = match.groups()
                 (old_line, old_end,
                  new_line, new_end) = [int(x or 1) for x in gr[:-1]]
                 old_line -= 1
                 new_line -= 1
 
                 context = len(gr) == 5
                 old_end += old_line
                 new_end += new_line
 
                 if context:
                     # skip context only if it's first line
                     if int(gr[0]) > 1:
                         lines.append({
                             'old_lineno': '...',
                             'new_lineno': '...',
                             'action':     Action.CONTEXT,
                             'line':       line,
                         })
 
                 line = lineiter.next()
 
                 while old_line < old_end or new_line < new_end:
                     command = ' '
                     if line:
                         command = line[0]
 
                     affects_old = affects_new = False
 
                     # ignore those if we don't expect them
                     if command in '#@':
                         continue
                     elif command == '+':
                         affects_new = True
                         action = Action.ADD
                         stats[0] += 1
                     elif command == '-':
                         affects_old = True
                         action = Action.DELETE
                         stats[1] += 1
                     else:
                         affects_old = affects_new = True
                         action = Action.UNMODIFIED
 
                     if not self._newline_marker.match(line):
                         old_line += affects_old
                         new_line += affects_new
                         lines.append({
                             'old_lineno':   affects_old and old_line or '',
                             'new_lineno':   affects_new and new_line or '',
                             'action':       action,
                             'line':         self._clean_line(line, command)
                         })
                         raw_diff.append(line)
 
                     line = lineiter.next()
 
                     if self._newline_marker.match(line):
                         # we need to append to lines, since this is not
                         # counted in the line specs of diff
                         lines.append({
                             'old_lineno':   '...',
                             'new_lineno':   '...',
                             'action':       Action.CONTEXT,
                             'line':         self._clean_line(line, command)
                         })
 
         except StopIteration:
             pass
         return ''.join(raw_diff), chunks, stats
 
     # FIXME: NEWDIFFS: dan: this replaces _parse_lines
     def _new_parse_lines(self, diff):
         """
         Parse the diff an return data for the template.
         """
 
         lineiter = iter(diff)
         stats = [0, 0]
         chunks = []
         raw_diff = []
 
         try:
             line = lineiter.next()
 
             while line:
                 raw_diff.append(line)
                 match = self._chunk_re.match(line)
 
                 if not match:
                     break
 
                 gr = match.groups()
                 (old_line, old_end,
                  new_line, new_end) = [int(x or 1) for x in gr[:-1]]
 
                 lines = []
                 hunk = {
                     'section_header': gr[-1],
                     'source_start': old_line,
                     'source_length': old_end,
                     'target_start': new_line,
                     'target_length': new_end,
                     'lines': lines,
                 }
                 chunks.append(hunk)
 
                 old_line -= 1
                 new_line -= 1
 
                 context = len(gr) == 5
                 old_end += old_line
                 new_end += new_line
 
                 line = lineiter.next()
 
                 while old_line < old_end or new_line < new_end:
                     command = ' '
                     if line:
                         command = line[0]
 
                     affects_old = affects_new = False
 
                     # ignore those if we don't expect them
                     if command in '#@':
                         continue
                     elif command == '+':
                         affects_new = True
                         action = Action.ADD
                         stats[0] += 1
                     elif command == '-':
                         affects_old = True
                         action = Action.DELETE
                         stats[1] += 1
                     else:
                         affects_old = affects_new = True
                         action = Action.UNMODIFIED
 
                     if not self._newline_marker.match(line):
                         old_line += affects_old
                         new_line += affects_new
                         lines.append({
                             'old_lineno':   affects_old and old_line or '',
                             'new_lineno':   affects_new and new_line or '',
                             'action':       action,
                             'line':         self._clean_line(line, command)
                         })
                         raw_diff.append(line)
 
                     line = lineiter.next()
 
                     if self._newline_marker.match(line):
                         # we need to append to lines, since this is not
                         # counted in the line specs of diff
                         if affects_old:
-                            action = Action.CONTEXT_OLD
+                            action = Action.OLD_NO_NL
                         elif affects_new:
-                            action = Action.CONTEXT_NEW
+                            action = Action.NEW_NO_NL
                         else:
                             raise Exception('invalid context for no newline')
 
                         lines.append({
                             'old_lineno':   None,
                             'new_lineno':   None,
                             'action':       action,
                             'line':         self._clean_line(line, command)
                         })
 
         except StopIteration:
             pass
         return ''.join(raw_diff), chunks, stats
 
     def _safe_id(self, idstring):
         """Make a string safe for including in an id attribute.
 
         The HTML spec says that id attributes 'must begin with
         a letter ([A-Za-z]) and may be followed by any number
         of letters, digits ([0-9]), hyphens ("-"), underscores
         ("_"), colons (":"), and periods (".")'. These regexps
         are slightly over-zealous, in that they remove colons
         and periods unnecessarily.
 
         Whitespace is transformed into underscores, and then
         anything which is not a hyphen or a character that
         matches \w (alphanumerics and underscore) is removed.
 
         """
         # Transform all whitespace to underscore
         idstring = re.sub(r'\s', "_", '%s' % idstring)
         # Remove everything that is not a hyphen or a member of \w
         idstring = re.sub(r'(?!-)\W', "", idstring).lower()
         return idstring
 
     def prepare(self, inline_diff=True):
         """
         Prepare the passed udiff for HTML rendering.
 
         :return: A list of dicts with diff information.
         """
         parsed = self._parser(inline_diff=inline_diff)
         self.parsed = True
         self.parsed_diff = parsed
         return parsed
 
     def as_raw(self, diff_lines=None):
         """
         Returns raw diff as a byte string
         """
         return self._diff.raw
 
     def as_html(self, table_class='code-difftable', line_class='line',
                 old_lineno_class='lineno old', new_lineno_class='lineno new',
                 code_class='code', enable_comments=False, parsed_lines=None):
         """
         Return given diff as html table with customized css classes
         """
         def _link_to_if(condition, label, url):
             """
             Generates a link if condition is meet or just the label if not.
             """
 
             if condition:
                 return '''<a href="%(url)s" class="tooltip"
                 title="%(title)s">%(label)s</a>''' % {
                     'title': _('Click to select line'),
                     'url': url,
                     'label': label
                 }
             else:
                 return label
         if not self.parsed:
             self.prepare()
 
         diff_lines = self.parsed_diff
         if parsed_lines:
             diff_lines = parsed_lines
 
         _html_empty = True
         _html = []
         _html.append('''<table class="%(table_class)s">\n''' % {
             'table_class': table_class
         })
 
         for diff in diff_lines:
             for line in diff['chunks']:
                 _html_empty = False
                 for change in line:
                     _html.append('''<tr class="%(lc)s %(action)s">\n''' % {
                         'lc': line_class,
                         'action': change['action']
                     })
                     anchor_old_id = ''
                     anchor_new_id = ''
                     anchor_old = "%(filename)s_o%(oldline_no)s" % {
                         'filename': self._safe_id(diff['filename']),
                         'oldline_no': change['old_lineno']
                     }
                     anchor_new = "%(filename)s_n%(oldline_no)s" % {
                         'filename': self._safe_id(diff['filename']),
                         'oldline_no': change['new_lineno']
                     }
                     cond_old = (change['old_lineno'] != '...' and
                                 change['old_lineno'])
                     cond_new = (change['new_lineno'] != '...' and
                                 change['new_lineno'])
                     if cond_old:
                         anchor_old_id = 'id="%s"' % anchor_old
                     if cond_new:
                         anchor_new_id = 'id="%s"' % anchor_new
 
                     if change['action'] != Action.CONTEXT:
                         anchor_link = True
                     else:
                         anchor_link = False
 
                     ###########################################################
                     # COMMENT ICONS
                     ###########################################################
                     _html.append('''\t<td class="add-comment-line"><span class="add-comment-content">''')
 
                     if enable_comments and change['action'] != Action.CONTEXT:
                         _html.append('''<a href="#"><span class="icon-comment-add"></span></a>''')
 
                     _html.append('''</span></td><td class="comment-toggle tooltip" title="Toggle Comment Thread"><i class="icon-comment"></i></td>\n''')
 
                     ###########################################################
                     # OLD LINE NUMBER
                     ###########################################################
                     _html.append('''\t<td %(a_id)s class="%(olc)s">''' % {
                         'a_id': anchor_old_id,
                         'olc': old_lineno_class
                     })
 
                     _html.append('''%(link)s''' % {
                         'link': _link_to_if(anchor_link, change['old_lineno'],
                                             '#%s' % anchor_old)
                     })
                     _html.append('''</td>\n''')
                     ###########################################################
                     # NEW LINE NUMBER
                     ###########################################################
 
                     _html.append('''\t<td %(a_id)s class="%(nlc)s">''' % {
                         'a_id': anchor_new_id,
                         'nlc': new_lineno_class
                     })
 
                     _html.append('''%(link)s''' % {
                         'link': _link_to_if(anchor_link, change['new_lineno'],
                                             '#%s' % anchor_new)
                     })
                     _html.append('''</td>\n''')
                     ###########################################################
                     # CODE
                     ###########################################################
                     code_classes = [code_class]
                     if (not enable_comments or
                             change['action'] == Action.CONTEXT):
                         code_classes.append('no-comment')
                     _html.append('\t<td class="%s">' % ' '.join(code_classes))
                     _html.append('''\n\t\t<pre>%(code)s</pre>\n''' % {
                         'code': change['line']
                     })
 
                     _html.append('''\t</td>''')
                     _html.append('''\n</tr>\n''')
         _html.append('''</table>''')
         if _html_empty:
             return None
         return ''.join(_html)
 
     def stat(self):
         """
         Returns tuple of added, and removed lines for this instance
         """
         return self.adds, self.removes
 
     def get_context_of_line(
             self, path, diff_line=None, context_before=3, context_after=3):
         """
         Returns the context lines for the specified diff line.
 
         :type diff_line: :class:`DiffLineNumber`
         """
         assert self.parsed, "DiffProcessor is not initialized."
 
         if None not in diff_line:
             raise ValueError(
                 "Cannot specify both line numbers: {}".format(diff_line))
 
         file_diff = self._get_file_diff(path)
         chunk, idx = self._find_chunk_line_index(file_diff, diff_line)
 
         first_line_to_include = max(idx - context_before, 0)
         first_line_after_context = idx + context_after + 1
         context_lines = chunk[first_line_to_include:first_line_after_context]
 
         line_contents = [
             _context_line(line) for line in context_lines
             if _is_diff_content(line)]
         # TODO: johbo: Interim fixup, the diff chunks drop the final newline.
         # Once they are fixed, we can drop this line here.
         if line_contents:
             line_contents[-1] = (
                 line_contents[-1][0], line_contents[-1][1].rstrip('\n') + '\n')
         return line_contents
 
     def find_context(self, path, context, offset=0):
         """
         Finds the given `context` inside of the diff.
 
         Use the parameter `offset` to specify which offset the target line has
         inside of the given `context`. This way the correct diff line will be
         returned.
 
         :param offset: Shall be used to specify the offset of the main line
             within the given `context`.
         """
         if offset < 0 or offset >= len(context):
             raise ValueError(
                 "Only positive values up to the length of the context "
                 "minus one are allowed.")
 
         matches = []
         file_diff = self._get_file_diff(path)
 
         for chunk in file_diff['chunks']:
             context_iter = iter(context)
             for line_idx, line in enumerate(chunk):
                 try:
                     if _context_line(line) == context_iter.next():
                         continue
                 except StopIteration:
                     matches.append((line_idx, chunk))
                 context_iter = iter(context)
 
         # Increment position and triger StopIteration
         # if we had a match at the end
         line_idx += 1
         try:
             context_iter.next()
         except StopIteration:
             matches.append((line_idx, chunk))
 
         effective_offset = len(context) - offset
         found_at_diff_lines = [
             _line_to_diff_line_number(chunk[idx - effective_offset])
             for idx, chunk in matches]
 
         return found_at_diff_lines
 
     def _get_file_diff(self, path):
         for file_diff in self.parsed_diff:
             if file_diff['filename'] == path:
                 break
         else:
             raise FileNotInDiffException("File {} not in diff".format(path))
         return file_diff
 
     def _find_chunk_line_index(self, file_diff, diff_line):
         for chunk in file_diff['chunks']:
             for idx, line in enumerate(chunk):
                 if line['old_lineno'] == diff_line.old:
                     return chunk, idx
                 if line['new_lineno'] == diff_line.new:
                     return chunk, idx
         raise LineNotInDiffException(
             "The line {} is not part of the diff.".format(diff_line))
 
 
 def _is_diff_content(line):
     return line['action'] in (
         Action.UNMODIFIED, Action.ADD, Action.DELETE)
 
 
 def _context_line(line):
     return (line['action'], line['line'])
 
 
 DiffLineNumber = collections.namedtuple('DiffLineNumber', ['old', 'new'])
 
 
 def _line_to_diff_line_number(line):
     new_line_no = line['new_lineno'] or None
     old_line_no = line['old_lineno'] or None
     return DiffLineNumber(old=old_line_no, new=new_line_no)
 
 
 class FileNotInDiffException(Exception):
     """
     Raised when the context for a missing file is requested.
 
     If you request the context for a line in a file which is not part of the
     given diff, then this exception is raised.
     """
 
 
 class LineNotInDiffException(Exception):
     """
     Raised when the context for a missing line is requested.
 
     If you request the context for a line in a file and this line is not
     part of the given diff, then this exception is raised.
     """
 
 
 class DiffLimitExceeded(Exception):
     pass