From ab983165a497ff788be86806a6b532ef6c8ff60a Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 20 Feb 2014 09:34:47 +0530
Subject: [PATCH] Conversion: Fix parsing of HTML 5 documents that are also
 valid XML but use non-namespaced inline svg

---
 src/calibre/ebooks/oeb/parse_utils.py | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/calibre/ebooks/oeb/parse_utils.py b/src/calibre/ebooks/oeb/parse_utils.py
index 1bb13d21a2..52f7976998 100644
--- a/src/calibre/ebooks/oeb/parse_utils.py
+++ b/src/calibre/ebooks/oeb/parse_utils.py
@@ -216,6 +216,14 @@ def clean_word_doc(data, log):
         data = pat.sub('', data)
     return data
 
+class HTML5Doc(ValueError):
+    pass
+
+def check_for_html5(prefix, root):
+    if re.search(r'<!DOCTYPE\s+html\s*>', prefix, re.IGNORECASE) is not None:
+        if root.xpath('//svg'):
+            raise HTML5Doc('This document appears to be un-namespaced HTML 5, should be parsed by the HTML 5 parser')
+
 def parse_html(data, log=None, decoder=None, preprocessor=None,
         filename='<string>', non_html_file_tags=frozenset()):
     if log is None:
@@ -257,7 +265,7 @@ def parse_html(data, log=None, decoder=None, preprocessor=None,
                 pat = re.compile(r'&(%s);'%('|'.join(user_entities.keys())))
                 data = pat.sub(lambda m:user_entities[m.group(1)], data)
 
-    data = clean_word_doc(data, log)
+    data = raw = clean_word_doc(data, log)
 
     # Setting huge_tree=True causes crashes in windows with large files
     parser = etree.XMLParser(no_network=True)
@@ -265,14 +273,17 @@ def parse_html(data, log=None, decoder=None, preprocessor=None,
     # Try with more & more drastic measures to parse
     try:
         data = etree.fromstring(data, parser=parser)
-    except etree.XMLSyntaxError:
+        check_for_html5(pre, data)
+    except (HTML5Doc, etree.XMLSyntaxError):
         log.debug('Initial parse failed, using more'
                 ' forgiving parsers')
-        data = xml_replace_entities(data)
+        raw = data = xml_replace_entities(raw)
         try:
             data = etree.fromstring(data, parser=parser)
-        except etree.XMLSyntaxError:
+            check_for_html5(pre, data)
+        except (HTML5Doc, etree.XMLSyntaxError):
             log.debug('Parsing %s as HTML' % filename)
+            data = raw
             try:
                 data = html5_parse(data)
             except: