Dont escape - when generating CFI

Also recognize both escaped and unescaped hyphens when parsing CFI

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

@@ -17,9 +17,11 @@ class Parser:
 
     def __init__(self):
         # All allowed unicode characters + escaped special characters
-        special_char = r'[\[\](),;=^-]'
-        unescaped_char = '[[\t\n\r -\ud7ff\ue000-\ufffd\U00010000-\U0010ffff]--%s]' % special_char
-        escaped_char = r'\^' + special_char
+        special_char = r'[\[\](),;=^]'
+        unescaped_char = f'[[\t\n\r -\ud7ff\ue000-\ufffd\U00010000-\U0010ffff]--{special_char}]'
+        # calibre used to escape hyphens as well, so recognize them even though
+        # not strictly spec compliant
+        escaped_char = r'\^' + special_char[:-1] + '-]'
         chars = r'(?:%s|(?:%s))+' % (unescaped_char, escaped_char)
         chars_no_space = chars.replace('0020', '0021')
         # No leading zeros allowed for integers

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

@@ -86,7 +86,9 @@ 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]', 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'), ''),

src/pyj/read_book/cfi.pyj

@@ -24,7 +24,7 @@ from __python__ import hash_literals
 from read_book.viewport import scroll_viewport, rem_size
 
 # CFI escaping {{{
-escape_pat = /[\[\],^();~@!-]/g
+escape_pat = /[\[\],^();~@!]/g
 unescape_pat = /[\^](.)/g
 
 def escape_for_cfi(raw):