Fix #6097 (Changing from lrf file to mobi)

src/calibre/ebooks/lrf/input.py

@@ -367,7 +367,7 @@ class LRFInput(InputFormatPlugin):
         xml = d.to_xml(write_files=True)
         if options.verbose > 2:
             open('lrs.xml', 'wb').write(xml.encode('utf-8'))
-        parser = etree.XMLParser(recover=True, no_network=True, huge_tree=True)
+        parser = etree.XMLParser(no_network=True, huge_tree=True)
         doc = etree.fromstring(xml, parser=parser)
         char_button_map = {}
         for x in doc.xpath('//CharButton[@refobj]'):

src/calibre/ebooks/lrf/objects.py

@@ -870,7 +870,7 @@ class Text(LRFStream):
         open_containers = collections.deque()
         for c in self.content:
             if isinstance(c, basestring):
-                s += prepare_string_for_xml(c)
+                s += prepare_string_for_xml(c).replace('\0', '')
             elif c is None:
                 if open_containers:
                     p = open_containers.pop()

src/calibre/ebooks/oeb/base.py

@@ -26,7 +26,7 @@ from calibre.ebooks.chardet import xml_to_unicode
 from calibre.ebooks.oeb.entitydefs import ENTITYDEFS
 from calibre.ebooks.conversion.preprocess import CSSPreProcessor
 
-RECOVER_PARSER = etree.XMLParser(recover=True, no_network=True, huge_tree=True)
+RECOVER_PARSER = etree.XMLParser(recover=True, no_network=True)
 
 XML_NS       = 'http://www.w3.org/XML/1998/namespace'
 XHTML_NS     = 'http://www.w3.org/1999/xhtml'

src/calibre/gui2/tools.py

@@ -221,6 +221,8 @@ def fetch_scheduled_recipe(arg):
     if lf.get('base_font_size', 0.0) != 0.0:
         recs.append(('base_font_size', lf['base_font_size'],
             OptionRecommendation.HIGH))
+        recs.append(('keep_ligatures', lf['keep_ligatures'],
+            OptionRecommendation.HIGH))
 
     lr = load_defaults('lrf_output')
     if lr.get('header', False):