EPUB Output: Pass through font-face rules. Fixes #3042 (Calibre ignores extra_css in recipe)

src/calibre/ebooks/oeb/stylizer.py

@@ -17,7 +17,7 @@ from weakref import WeakKeyDictionary
 from xml.dom import SyntaxErr as CSSSyntaxError
 import cssutils
 from cssutils.css import CSSStyleRule, CSSPageRule, CSSStyleDeclaration, \
-    CSSValueList, cssproperties
+    CSSValueList, CSSFontFaceRule, cssproperties
 from cssutils import profile as cssprofiles
 from lxml import etree
 from lxml.cssselect import css_to_xpath, ExpressionError, SelectorSyntaxError
@@ -119,6 +119,7 @@ class Stylizer(object):
         head = xpath(tree, '/h:html/h:head')[0]
         parser = cssutils.CSSParser(fetcher=self._fetch_css_file,
                 log=logging.getLogger('calibre.css'))
+        self.font_face_rules = []
         for elem in head:
             if elem.tag == XHTML('style') and elem.text \
                and elem.get('type', CSS_MIME) in OEB_STYLES:
@@ -210,6 +211,8 @@ class Stylizer(object):
         elif isinstance(rule, CSSPageRule):
             style = self.flatten_style(rule.style)
             self.page_rule.update(style)
+        elif isinstance(rule, CSSFontFaceRule):
+            self.font_face_rules.append(rule)
         return results
 
     def flatten_style(self, cssstyle):

src/calibre/ebooks/oeb/transforms/flatcss.py

@@ -317,7 +317,10 @@ class CSSFlattener(object):
         items.sort()
         css = '; '.join("%s: %s" % (key, val) for key, val in items)
         style = etree.SubElement(head, XHTML('style'), type=CSS_MIME)
-        style.text = "@page { %s; }" % css
+        style.text = "\n\t\t@page { %s; }" % css
+        rules = [r.cssText for r in stylizer.font_face_rules]
+        for r in rules:
+            style.text += '\n\t\t'+r+'\n'
 
     def replace_css(self, css):
         manifest = self.oeb.manifest