Horizontal rule processing takes a long time or possibly forever #1055
Description
When I feed in certain strings with lots of "-" characters, it takes incredibly long for the markdown function to return a result. It may not hang forever, but I've been waiting several hours for the library to process about 30 characters.
Here's an example
# python3 Python 3.8.6 (default, Oct 13 2020, 20:37:26) [GCC 8.3.0] on linux Type "help", "copyright", "credits" or "license" for more information. >>> import markdown >>> markdown.markdown("------------------------------hello---------------------") After several hours the function is still calculating. Here's a stack trace from when I interrupt the computation:
File "<stdin>", line 1, in <module> File "/usr/local/lib/python3.8/site-packages/markdown/core.py", line 386, in markdown return md.convert(text) File "/usr/local/lib/python3.8/site-packages/markdown/core.py", line 263, in convert root = self.parser.parseDocument(self.lines).getroot() File "/usr/local/lib/python3.8/site-packages/markdown/blockparser.py", line 90, in parseDocument self.parseChunk(self.root, '\n'.join(lines)) File "/usr/local/lib/python3.8/site-packages/markdown/blockparser.py", line 105, in parseChunk self.parseBlocks(parent, text.split('\n\n')) File "/usr/local/lib/python3.8/site-packages/markdown/blockparser.py", line 122, in parseBlocks if processor.test(parent, blocks[0]): File "/usr/local/lib/python3.8/site-packages/markdown/blockprocessors.py", line 504, in test m = self.SEARCH_RE.search(block) When I remove enough of the - characters I will eventually get a result, although it can still take a few minutes. markdown.markdown("---------------------------hello-------------------") will actually return a result but it takes about 20-30 seconds.
I'm using version 3.3.2 of the library