From 464979673a45a811d9293ee542b60bbdd29b52a1 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sun, 17 Jul 2016 09:26:13 +0530
Subject: [PATCH] E-book viewer: Fix the show metadata button not reading EPUB
 3 metadata

---
 src/calibre/ebooks/metadata/opf2.py     | 3 +++
 src/calibre/ebooks/oeb/iterator/book.py | 7 ++++---
 src/calibre/gui2/viewer/main.py         | 5 ++---
 src/calibre/gui2/viewer/ui.py           | 3 +--
 4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/src/calibre/ebooks/metadata/opf2.py b/src/calibre/ebooks/metadata/opf2.py
index 3d8be41064..fa45b516a4 100644
--- a/src/calibre/ebooks/metadata/opf2.py
+++ b/src/calibre/ebooks/metadata/opf2.py
@@ -620,6 +620,9 @@ class OPF(object):  # {{{
         self._user_metadata_ = temp.get_all_user_metadata(True)
 
     def to_book_metadata(self):
+        if self.package_version >= 3.0:
+            from calibre.ebooks.metadata.opf3 import read_metadata
+            return read_metadata(self.root)
         ans = MetaInformation(self)
         for n, v in self._user_metadata_.items():
             ans.set_user_metadata(n, v)
diff --git a/src/calibre/ebooks/oeb/iterator/book.py b/src/calibre/ebooks/oeb/iterator/book.py
index 437d1aaa93..47ac05536c 100644
--- a/src/calibre/ebooks/oeb/iterator/book.py
+++ b/src/calibre/ebooks/oeb/iterator/book.py
@@ -139,9 +139,10 @@ class EbookIterator(BookmarksMixin):
         self.book_format, self.pathtoopf, input_fmt = run_extract_book(
             self.pathtoebook, self.base, only_input_plugin=only_input_plugin, view_kepub=view_kepub, processed=processed)
         self.opf = OPF(self.pathtoopf, os.path.dirname(self.pathtoopf))
-        self.language = self.opf.language
-        if self.language:
-            self.language = self.language.lower()
+        self.mi = self.opf.to_book_metadata()
+        self.language = None
+        if self.mi.languages:
+            self.language = self.mi.languages[0].lower()
         ordered = [i for i in self.opf.spine if i.is_linear] + \
                   [i for i in self.opf.spine if not i.is_linear]
         self.spine = []
diff --git a/src/calibre/gui2/viewer/main.py b/src/calibre/gui2/viewer/main.py
index 2c62aa8e3f..d9756934cf 100644
--- a/src/calibre/gui2/viewer/main.py
+++ b/src/calibre/gui2/viewer/main.py
@@ -953,10 +953,9 @@ class EbookViewer(MainWindow):
                         det_msg=tb, show=True)
             self.close_progress_indicator()
         else:
-            self.metadata.show_opf(self.iterator.opf,
-                    self.iterator.book_format)
+            self.metadata.show_metadata(self.iterator.mi, self.iterator.book_format)
             self.view.current_language = self.iterator.language
-            title = self.iterator.opf.title
+            title = self.iterator.mi.title
             if not title:
                 title = os.path.splitext(os.path.basename(pathtoebook))[0]
             if self.iterator.toc:
diff --git a/src/calibre/gui2/viewer/ui.py b/src/calibre/gui2/viewer/ui.py
index 4a0d11e997..ef0c99d8b2 100644
--- a/src/calibre/gui2/viewer/ui.py
+++ b/src/calibre/gui2/viewer/ui.py
@@ -80,14 +80,13 @@ class Metadata(QWebView):  # {{{
     def update_layout(self):
         self.setGeometry(0, 0, self.parent().width(), self.parent().height())
 
-    def show_opf(self, opf, ext=''):
+    def show_metadata(self, mi, ext=''):
         from calibre.gui2.book_details import render_html, css
         from calibre.ebooks.metadata.book.render import mi_to_html
 
         def render_data(mi, use_roman_numbers=True, all_fields=False):
             return mi_to_html(mi, use_roman_numbers=use_roman_numbers, rating_font=rating_font(), rtl=is_rtl())
 
-        mi = opf.to_book_metadata()
         html = render_html(mi, css(), True, self, render_data_func=render_data)
         self.setHtml(html)