From 7f7a08f44bed5e6bbe3a7cd65d642d4fe1d61c7b Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 9 Jan 2016 09:48:17 +0530
Subject: [PATCH] E-book viewer: Disallow hyphenation in documents that use
 mathematical typesetting as the hyphenation breaks that typesetting

---
 src/calibre/ebooks/oeb/display/mathjax.coffee | 1 +
 src/calibre/gui2/viewer/documentview.py       | 5 +++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/calibre/ebooks/oeb/display/mathjax.coffee b/src/calibre/ebooks/oeb/display/mathjax.coffee
index 14633b8fbc..cef4ede52d 100644
--- a/src/calibre/ebooks/oeb/display/mathjax.coffee
+++ b/src/calibre/ebooks/oeb/display/mathjax.coffee
@@ -74,6 +74,7 @@ class MathJax
         if script != null or document.getElementsByTagName('math').length > 0
             this.math_present = true
             this.load_mathjax(user_config)
+        return this.math_present
 
     after_resize: () ->
         if not this.math_present or this.hub == null
diff --git a/src/calibre/gui2/viewer/documentview.py b/src/calibre/gui2/viewer/documentview.py
index e17240177a..09728655cf 100644
--- a/src/calibre/gui2/viewer/documentview.py
+++ b/src/calibre/gui2/viewer/documentview.py
@@ -108,6 +108,7 @@ class Document(QWebPage):  # {{{
         self.js_loader = JavaScriptLoader(
                     dynamic_coffeescript=self.debug_javascript)
         self.in_fullscreen_mode = False
+        self.math_present = False
 
         self.setLinkDelegationPolicy(self.DelegateAllLinks)
         self.scroll_marks = []
@@ -232,7 +233,7 @@ class Document(QWebPage):  # {{{
     @property
     def hyphenatable(self):
         # Qt fails to render soft hyphens correctly on windows xp
-        return not isxp and self.hyphenate and getattr(self, 'loaded_lang', '')
+        return not isxp and self.hyphenate and getattr(self, 'loaded_lang', '') and not self.math_present
 
     @pyqtSlot()
     def init_hyphenate(self):
@@ -257,6 +258,7 @@ class Document(QWebPage):  # {{{
         self.javascript('window.paged_display.read_document_margins()')
         self.set_bottom_padding(0)
         self.fit_images()
+        self.math_present = self.javascript('window.mathjax.check_for_math()', bool)
         self.init_hyphenate()
         self.javascript('full_screen.save_margins()')
         if self.in_fullscreen_mode:
@@ -267,7 +269,6 @@ class Document(QWebPage):  # {{{
         evaljs = self.mainFrame().evaluateJavaScript
         for pl in self.all_viewer_plugins:
             pl.run_javascript(evaljs)
-        self.javascript('window.mathjax.check_for_math()')
         self.first_load = False
 
     def colors(self):