From 95d15ae9ffbd2373b3ac810f3becc8c9c41b3e29 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 13 May 2017 08:32:55 +0530
Subject: [PATCH] Fix an infinite recursion error if the user chooses a
 non-existent default author search source

Fixes #1690449 [Maximum recursion depth exceeded error](https://bugs.launchpad.net/calibre/+bug/1690449)
---
 src/calibre/ebooks/metadata/book/render.py     | 7 ++++---
 src/calibre/ebooks/metadata/search_internet.py | 3 +++
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/calibre/ebooks/metadata/book/render.py b/src/calibre/ebooks/metadata/book/render.py
index 6316e23421..2ff4ebcaa7 100644
--- a/src/calibre/ebooks/metadata/book/render.py
+++ b/src/calibre/ebooks/metadata/book/render.py
@@ -12,7 +12,7 @@ from binascii import hexlify
 
 from calibre import prepare_string_for_xml, force_unicode
 from calibre.ebooks.metadata import fmt_sidx, rating_to_stars
-from calibre.ebooks.metadata.search_internet import name_for, url_for_author_search, url_for_book_search, qquote
+from calibre.ebooks.metadata.search_internet import name_for, url_for_author_search, url_for_book_search, qquote, DEFAULT_AUTHOR_SOURCE
 from calibre.ebooks.metadata.sources.identify import urls_from_identifiers
 from calibre.constants import filesystem_encoding
 from calibre.library.comments import comments_to_html, markdown
@@ -56,7 +56,7 @@ def search_href(search_term, value):
     return prepare_string_for_xml('search:' + hexlify(search.encode('utf-8')), True)
 
 
-DEFAULT_AUTHOR_LINK = 'search-goodreads'
+DEFAULT_AUTHOR_LINK = 'search-{}'.format(DEFAULT_AUTHOR_SOURCE)
 
 
 def author_search_href(which, title=None, author=None):
@@ -67,7 +67,8 @@ def author_search_href(which, title=None, author=None):
         key, search_type = which.rpartition('-')[::2]
     name = name_for(key)
     if name is None:
-        return author_search_href(DEFAULT_AUTHOR_LINK, title=title, author=author)
+        search_type = 'author'
+        return author_search_href(DEFAULT_AUTHOR_LINK.partition('-')[2], title=title, author=author)
     if search_type == 'author':
         tt = _('Search {0} for the author: {1}').format(name, author)
     else:
diff --git a/src/calibre/ebooks/metadata/search_internet.py b/src/calibre/ebooks/metadata/search_internet.py
index d1b73fe4bc..5f0659390a 100644
--- a/src/calibre/ebooks/metadata/search_internet.py
+++ b/src/calibre/ebooks/metadata/search_internet.py
@@ -37,6 +37,9 @@ NAMES = {
     'gimg': _('Google images'),
 }
 
+DEFAULT_AUTHOR_SOURCE = 'goodreads'
+assert DEFAULT_AUTHOR_SOURCE in AUTHOR_SEARCHES
+
 name_for = NAMES.get
 all_book_searches = BOOK_SEARCHES.__iter__
 all_author_searches = AUTHOR_SEARCHES.__iter__