htmlToText: Don't replace inline element tags with spaces

They are not meant to be displayed like this, so they look weird sometimes.
For example, Mastodon splits long links between spans, so the Fediverse plugin
always displayed them broken.

src/utils/web.py

@@ -222,12 +222,16 @@ def getEncoding(s):
     except:
         return None
 
+
+# From beautifulsoup (version 4.10.0, bs4/builder/__init__.py, line 391)
+_block_elements = set(["address", "article", "aside", "blockquote", "canvas", "dd", "div", "dl", "dt", "fieldset", "figcaption", "figure", "footer", "form", "h1", "h2", "h3", "h4", "h5", "h6", "header", "hr", "li", "main", "nav", "noscript", "ol", "output", "p", "pre", "section", "table", "tfoot", "ul", "video"])
+
 class HtmlToText(HTMLParser, object):
     """Taken from some eff-bot code on c.l.p."""
     entitydefs = entitydefs.copy()
     entitydefs['nbsp'] = ' '
     entitydefs['apos'] = '\''
-    def __init__(self, tagReplace=' '):
+    def __init__(self, tagReplace=None):
         self.data = []
         self.tagReplace = tagReplace
         super(HtmlToText, self).__init__()
@@ -235,11 +239,20 @@ class HtmlToText(HTMLParser, object):
     def append(self, data):
         self.data.append(data)
 
+    def getTagReplace(self, tag):
+        if self.tagReplace is None:
+            if tag in _block_elements:
+                return ' '
+            else:
+                return ''
+        else:
+            return self.tagReplace
+
     def handle_starttag(self, tag, attr):
-        self.append(self.tagReplace)
+        self.append(self.getTagReplace(tag))
 
     def handle_endtag(self, tag):
-        self.append(self.tagReplace)
+        self.append(self.getTagReplace(tag))
 
     def handle_data(self, data):
         self.append(data)
@@ -267,7 +280,7 @@ class HtmlToText(HTMLParser, object):
     def handle_charref(self, name):
         self.append(self.unescape('&#%s;' % name))
 
-def htmlToText(s, tagReplace=' '):
+def htmlToText(s, tagReplace=None):
     """Turns HTML into text.  tagReplace is a string to replace HTML tags with.
     """
     encoding = getEncoding(s)

test/test_utils.py

@@ -541,6 +541,11 @@ class NetTest(SupyTestCase):
         self.assertTrue(f('2001:888:0:1::666'))
 
 class WebTest(SupyTestCase):
+    def testHtmlToText(self):
+        self.assertEqual(
+            utils.web.htmlToText('foo<p>bar<span>baz</span>qux</p>quux'),
+            'foo barbazqux quux')
+
     def testGetDomain(self):
         url = 'http://slashdot.org/foo/bar.exe'
         self.assertEqual(utils.web.getDomain(url), 'slashdot.org')