From 235b7e38c197ba4a3c17531e516610af8795e348 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 23 Nov 2021 21:26:18 +0530
Subject: [PATCH] Fix inefficient regex that slows down a lot with certain
input. Fixes #1951979 [Private
bug](https://bugs.launchpad.net/calibre/+bug/1951979)
---
src/calibre/ebooks/conversion/preprocess.py | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/src/calibre/ebooks/conversion/preprocess.py b/src/calibre/ebooks/conversion/preprocess.py
index dd1322c8a0..ba5ee0da7f 100644
--- a/src/calibre/ebooks/conversion/preprocess.py
+++ b/src/calibre/ebooks/conversion/preprocess.py
@@ -46,7 +46,7 @@
def sanitize_head(match):
- x = match.group(1)
+ x = match.group(1).strip()
x = _span_pat.sub('', x)
return '<head>\n%s\n</head>' % x
@@ -380,8 +380,7 @@ def html_preprocess_rules():
(re.compile(r'\s{10000,}'), ''),
# Some idiotic HTML generators (Frontpage I'm looking at you)
# Put all sorts of crap into <head>. This messes up lxml
- (re.compile(r'<head[^>]*>\n*(.*?)\n*</head>', re.IGNORECASE|re.DOTALL),
- sanitize_head),
+ (re.compile(r'<head[^>]*>(.*?)</head>', re.IGNORECASE|re.DOTALL), sanitize_head),
# Convert all entities, since lxml doesn't handle them well
(re.compile(r'&(\S+?);'), convert_entities),
# Remove the <![if/endif tags inserted by everybody's darling, MS Word