allow a wrap_width value of None for unlimited line lengths

README.rst

@@ -143,6 +143,7 @@ wrap, wrap_width
   If ``wrap`` is set to ``True``, all text paragraphs are wrapped at
   ``wrap_width`` characters. Defaults to ``False`` and ``80``.
   Use with ``newline_style=BACKSLASH`` to keep line breaks in paragraphs.
+  A `wrap_width` value of `None` allows unlimited line lengths.
 
 Options may be specified as kwargs to the ``markdownify`` function, or as a
 nested ``Options`` class in ``MarkdownConverter`` subclasses.

markdownify/__init__.py

@@ -398,18 +398,19 @@ def convert_p(self, el, text, convert_as_inline):
             # Preserve newlines (and preceding whitespace) resulting
             # from <br> tags.  Newlines in the input have already been
             # replaced by spaces.
-            lines = text.split('\n')
-            new_lines = []
-            for line in lines:
-                line = line.lstrip()
-                line_no_trailing = line.rstrip()
-                trailing = line[len(line_no_trailing):]
-                line = fill(line,
-                            width=self.options['wrap_width'],
-                            break_long_words=False,
-                            break_on_hyphens=False)
-                new_lines.append(line + trailing)
-            text = '\n'.join(new_lines)
+            if self.options['wrap_width'] is not None:
+                lines = text.split('\n')
+                new_lines = []
+                for line in lines:
+                    line = line.lstrip()
+                    line_no_trailing = line.rstrip()
+                    trailing = line[len(line_no_trailing):]
+                    line = fill(line,
+                                width=self.options['wrap_width'],
+                                break_long_words=False,
+                                break_on_hyphens=False)
+                    new_lines.append(line + trailing)
+                text = '\n'.join(new_lines)
         return '\n\n%s\n\n' % text if text else ''
 
     def convert_pre(self, el, text, convert_as_inline):

tests/test_conversions.py

@@ -219,6 +219,7 @@ def test_p():
     assert md('<p>123456789 123456789</p>') == '\n\n123456789 123456789\n\n'
     assert md('<p>123456789\n\n\n123456789</p>') == '\n\n123456789\n123456789\n\n'
     assert md('<p>123456789\n\n\n123456789</p>', wrap=True, wrap_width=80) == '\n\n123456789 123456789\n\n'
+    assert md('<p>123456789\n\n\n123456789</p>', wrap=True, wrap_width=None) == '\n\n123456789 123456789\n\n'
     assert md('<p>123456789 123456789</p>', wrap=True, wrap_width=10) == '\n\n123456789\n123456789\n\n'
     assert md('<p><a href="https://example.com">Some long link</a></p>', wrap=True, wrap_width=10) == '\n\n[Some long\nlink](https://example.com)\n\n'
     assert md('<p>12345<br />67890</p>', wrap=True, wrap_width=10, newline_style=BACKSLASH) == '\n\n12345\\\n67890\n\n'