From acba68e24088bcd06568162f361fdcfd3a368a99 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 8 May 2017 09:34:31 +0530
Subject: [PATCH] PDF Output: Fix a regression in the previous release that
 broke conversion to PDF for some files. Fixes #1689192 [Private
 bug](https://bugs.launchpad.net/calibre/+bug/1689192)

---
 src/calibre/ebooks/pdf/render/from_html.py |  6 +++---
 src/calibre/gui2/viewer/documentview.py    | 10 +++++-----
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/calibre/ebooks/pdf/render/from_html.py b/src/calibre/ebooks/pdf/render/from_html.py
index 01f74dffdc..f7d3d2fdee 100644
--- a/src/calibre/ebooks/pdf/render/from_html.py
+++ b/src/calibre/ebooks/pdf/render/from_html.py
@@ -351,15 +351,15 @@ class PDFWriter(QObject):
         evaljs(self.paged_js)
         self.load_mathjax()
 
-        amap = evaljs('''
+        amap = json.loads(evaljs('''
         document.body.style.backgroundColor = "white";
         paged_display.set_geometry(1, %d, %d, %d);
         paged_display.layout();
         paged_display.fit_images();
         ret = book_indexing.all_links_and_anchors();
         window.scrollTo(0, 0); // This is needed as getting anchor positions could have caused the viewport to scroll
-        ret;
-        '''%(self.margin_top, 0, self.margin_bottom))
+        JSON.stringify(ret);
+        '''%(self.margin_top, 0, self.margin_bottom)))
 
         if not isinstance(amap, dict):
             amap = {'links':[], 'anchors':{}}  # Some javascript error occurred
diff --git a/src/calibre/gui2/viewer/documentview.py b/src/calibre/gui2/viewer/documentview.py
index 7f462cc149..bd28c02bc2 100644
--- a/src/calibre/gui2/viewer/documentview.py
+++ b/src/calibre/gui2/viewer/documentview.py
@@ -247,10 +247,10 @@ class Document(QWebPage):  # {{{
         self.first_load = False
 
     def colors(self):
-        ans = self.javascript('''
+        ans = json.loads(self.javascript('''
             bs = getComputedStyle(document.body);
-            [bs.backgroundColor, bs.color]
-            ''')
+            JSON.stringify([bs.backgroundColor, bs.color])
+            '''))
         return ans if isinstance(ans, list) else ['white', 'black']
 
     def read_anchor_positions(self, use_cache=True):
@@ -299,8 +299,8 @@ class Document(QWebPage):  # {{{
     def column_boundaries(self):
         if not self.loaded_javascript:
             return (0, 1)
-        ans = self.javascript(u'paged_display.column_boundaries()')
-        return tuple(int(x) for x in ans)
+        ans = self.javascript(u'JSON.stringify(paged_display.column_boundaries())')
+        return tuple(int(x) for x in json.loads(ans))
 
     def after_resize(self):
         if self.in_paged_mode: