From 592c00d55c0aed3cca70fd5d62d95f376db7cefd Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 12 Nov 2015 11:22:29 +0530
Subject: [PATCH] Report unhandled exceptions to user

---
 src/pyj/book_list/boss.pyj | 10 ++++++++++
 src/pyj/modals.pyj         |  6 +++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/pyj/book_list/boss.pyj b/src/pyj/book_list/boss.pyj
index 6b69120a7c..a82b327f02 100644
--- a/src/pyj/book_list/boss.pyj
+++ b/src/pyj/book_list/boss.pyj
@@ -2,6 +2,8 @@
 # License: GPL v3 Copyright: 2015, Kovid Goyal <kovid at kovidgoyal.net>
 
 from book_list.ui import UI
+from modals import error_dialog
+from gettext import gettext as _
 
 class Boss:
 
@@ -11,7 +13,15 @@ class Boss:
         self.current_library_name = interface_data['library_map'][self.current_library_id]
         self.update_window_title()
         self.ui = UI(interface_data)
+        window.onerror = bind(self.onerror, self)
 
     def update_window_title(self):
         document.title = 'calibre :: ' + self.current_library_name
 
+    def onerror(self, msg, script_url, line_number, column_number, error_object):
+        fname = str.rpartition(script_url, '/')[-1] or script_url
+        msg = msg + '<br><span style="font-size:smaller">' + str.format('Error at {}:{}:{}', fname, line_number, column_number or '') + '</span>'
+        details = ''
+        if error_object and error_object.stack:
+            details = error_object.stack
+        error_dialog(_('Unhandled error'), msg, details)
diff --git a/src/pyj/modals.pyj b/src/pyj/modals.pyj
index d9820f26bd..fd3b5641c4 100644
--- a/src/pyj/modals.pyj
+++ b/src/pyj/modals.pyj
@@ -101,6 +101,10 @@ def create_simple_dialog(title, msg, details, icon_name, prefix):
             show_details.style.display = 'none'
             show_details.nextSibling.style.display = 'block'
         )
+        is_html_msg = /<[a-zA-Z]/.test(msg)
+        html_container = E.div()
+        if is_html_msg:
+            html_container.innerHTML = msg
         parent.appendChild(
             E.div(
                 style='max-width:60em; text-align: left',
@@ -108,7 +112,7 @@ def create_simple_dialog(title, msg, details, icon_name, prefix):
                     E.i(class_='fa fa-lg fa-' + icon_name, style='color:red'), E.span('\xa0' + prefix + '\xa0', style='font-variant:small-caps'), title,
                     style='font-weight: bold; font-size: ' + get_font_size('title')
                 ),
-                E.div(msg, style='padding-top: 1em; margin-top: 1em; border-top: 1px solid currentColor'),
+                E.div((html_container if is_html_msg else msg), style='padding-top: 1em; margin-top: 1em; border-top: 1px solid currentColor'),
                 E.div(style='display: ' + ('block' if details else 'none'),
                     show_details,
                     E.div(details,