E-book viewer: Fix sorting of highlights incorrect in books that use HTML ids with a hyphen in them. Fixes #1951507 [Private bug](https://bugs.launchpad.net/calibre/+bug/1951507)

src/calibre/ebooks/epub/cfi/parse.py

@@ -17,7 +17,7 @@ class Parser:
 
     def __init__(self):
         # All allowed unicode characters + escaped special characters
-        special_char = r'[\[\](),;=^]'
+        special_char = r'[\[\](),;=^-]'
         unescaped_char = '[[\t\n\r -\ud7ff\ue000-\ufffd\U00010000-\U0010ffff]--%s]' % special_char
         escaped_char = r'\^' + special_char
         chars = r'(?:%s|(?:%s))+' % (unescaped_char, escaped_char)

src/calibre/ebooks/epub/cfi/tests.py

@@ -86,6 +86,7 @@ class Tests(unittest.TestCase):
 
             # Test parsing of text assertions
             ('/1:3[aa^,b]', a('aa,b'), ''),
+            ('/1:3[aa^-b]', a('aa-b'), ''),
             ('/1:3[aa^,b,c1]', a('aa,b', 'c1'), ''),
             ('/1:3[,aa^,b]', a(after='aa,b'), ''),
             ('/1:3[;s=a]', a(s='a'), ''),