always escape \ when needed

html2text.py

@@ -744,7 +744,7 @@ def optwrap(self, text):
 ordered_list_matcher = re.compile(r'\d+\.\s')
 unordered_list_matcher = re.compile(r'[-\*\+]\s')
 md_chars_matcher = re.compile(r"([\\\[\]\(\)])")
-md_chars_matcher_all = re.compile(r"([\\`\*_{}\[\]\(\)#!])")
+md_chars_matcher_all = re.compile(r"([`\*_{}\[\]\(\)#!])")
 md_dot_matcher = re.compile(r"""
     ^             # start of line
     (\s*\d+)      # optional whitespace and a number
@@ -764,6 +764,12 @@ def optwrap(self, text):
     (?=\s|\-)     # followed by whitespace (bullet list, or spaced out hr)
                   # or another dash (header or hr)
     """, flags=re.MULTILINE | re.VERBOSE)
+slash_chars = r'\`*_{}[]()#+-.!'
+md_backslash_matcher = re.compile(r'''
+    (\\)          # match one slash
+    (?=[%s])      # followed by a char that requires escaping
+    ''' % re.escape(slash_chars),
+    flags=re.VERBOSE)
 
 def skipwrap(para):
     # If the text begins with four spaces or one tab, it's a code block; don't wrap
@@ -807,6 +813,7 @@ def escape_md(text):
 
 def escape_md_section(text, snob=False):
     """Escapes markdown-sensitive characters across whole document sections."""
+    text = md_backslash_matcher.sub(r"\\\1", text)
     if snob:
         text = md_chars_matcher_all.sub(r"\\\1", text)
     text = md_dot_matcher.sub(r"\1\\\2", text)

test/normal.html

@@ -132,5 +132,9 @@ <h1>
         <br>
         - - -
     </p>
+
+    <p>
+        c:\tmp, \\server\path, \_/, foo\bar, #\#, \\#
+    </p>
   </body>
 </html>

test/normal.md

@@ -50,3 +50,5 @@ not a hr
 \---  
 \- - -
 
+c:\tmp, \\\server\path, \\_/, foo\bar, #\\#, \\\\#
+

test/normal_escape_snob.html

@@ -28,9 +28,6 @@ <h1>
         <li>
           <span>apple</span>
         </li>
-        <li>
-          <span>yam\\sweet potato</span>
-        </li>
       </ul>
       <li>
         <span>final</span>
@@ -136,5 +133,9 @@ <h1>
         <br>
         - - -
     </p>
+
+    <p>
+        c:\tmp, \\server\path, \_/, foo\bar, #\#, \\#
+    </p>
   </body>
 </html>

test/normal_escape_snob.md

@@ -6,7 +6,6 @@ first issue
   * _**bold italic**_
     * orange
     * apple
-    * yam\\\\sweet potato
   * final
 
 text to separate lists
@@ -52,3 +51,5 @@ not a hr
 \---  
 \- - -
 
+c:\tmp, \\\server\path, \\\_/, foo\bar, \#\\\#, \\\\\#
+