Code cosmetics

Bugfix missing bleach tags (#3080)
Bugfix pdfreader

cps/clean_html.py

@@ -24,13 +24,21 @@ log = logger.create()
 try:
     # at least bleach 6.0 is needed -> incomplatible change from list arguments to set arguments
     from bleach import clean as clean_html
+    from bleach.sanitizer import ALLOWED_TAGS
+    bleach = True
 except ImportError:
     from nh3 import clean as clean_html
+    bleach = False
 
 
 def clean_string(unsafe_text, book_id=0):
     try:
-        safe_text = clean_html(unsafe_text)
+        if bleach:
+            allowed_tags = list(ALLOWED_TAGS)
+            allowed_tags.extend(['p', 'span', 'div', 'pre'])
+            safe_text = clean_html(unsafe_text, tags=set(allowed_tags))
+        else:
+            safe_text = clean_html(unsafe_text)
     except ParserError as e:
         log.error("Comments of book {} are corrupted: {}".format(book_id, e))
         safe_text = ""