Repository navigation
html.parser: check_for_whole_start_tag crashes with AssertionError on empty string #140877
Closed as not planned
Description
Bug report
Bug description:
The html.parser.HTMLParser method check_for_whole_start_tag crashes with an AssertionError when its rawdata is an empty string.
from html.parser import HTMLParser
parser = HTMLParser()
parser.feed('')
result = parser.check_for_whole_start_tag(0)Traceback (most recent call last):
File "/data/src/test.py", line 11, in <module>
result = parser.check_for_whole_start_tag(0)
File "/home/hdd/miniconda3/lib/python3.13/html/parser.py", line 394, in check_for_whole_start_tag
raise AssertionError("we should not get here!")
AssertionError: we should not get here!I think the internal code should gracefully handle this None match by returning -1 instead if an AssertionError?
CPython versions tested on:
3.13
Operating systems tested on:
Linux
Activity
T90REAL commentedon Nov 1, 2025
Not only empty string, but also some incomplete tag such as '<ª' would trigger this assertion.
efimov-mikhail commentedon Nov 1, 2025
cc @serhiy-storchaka because of 135930
serhiy-storchaka commentedon Nov 1, 2025
This works as expected.
check_for_whole_start_tag()should only be called if the next characters are<followed by an ASCII letter. Assertions just check an internal consistency of the code.