From 112f203a12ff5cc221c7ea221fcd49b06ba35df9 Mon Sep 17 00:00:00 2001
From: Leonard Richardson <leonardr@segfault.org>
Date: Fri, 2 Feb 2018 12:25:13 -0500
Subject: [PATCH] Add a unique index to genres.name.

---
 migration/20180202-genre-name-is-unique.sql | 10 ++++++++++
 model.py                                    |  4 ++--
 tests/test_model.py                         |  9 ++++++++-
 3 files changed, 20 insertions(+), 3 deletions(-)
 create mode 100644 migration/20180202-genre-name-is-unique.sql

diff --git a/migration/20180202-genre-name-is-unique.sql b/migration/20180202-genre-name-is-unique.sql
new file mode 100644
index 000000000..790fab849
--- /dev/null
+++ b/migration/20180202-genre-name-is-unique.sql
@@ -0,0 +1,10 @@
+-- genres.name should be indexed and unique.
+DO $$ 
+    BEGIN
+        BEGIN
+create unique index ix_genres_name on genres (name);
+        EXCEPTION
+            WHEN OTHERS THEN RAISE NOTICE 'WARNING: it looks like ix_genres_name already exists; it was probably created on initial database creation.';
+        END;
+    END;
+$$;
diff --git a/model.py b/model.py
index 1cc52f44a..a438af4d0 100644
--- a/model.py
+++ b/model.py
@@ -5876,7 +5876,7 @@ class Genre(Base, HasFullTableCache):
     """
     __tablename__ = 'genres'
     id = Column(Integer, primary_key=True)
-    name = Column(Unicode)
+    name = Column(Unicode, unique=True, index=True)
 
     # One Genre may have affinity with many Subjects.
     subjects = relationship("Subject", backref="genre")
@@ -8708,7 +8708,7 @@ def cautious_http_get(cls, url, headers, **kwargs):
 
     # Sites that cause problems for us if we make automated
     # HTTP requests to them while trying to find free books.
-    AVOID_WHEN_CAUTIOUS_DOMAINS = ['gutenberg.org']
+    AVOID_WHEN_CAUTIOUS_DOMAINS = ['gutenberg.org', 'books.google.com']
 
     @classmethod
     def get_would_be_useful(
diff --git a/tests/test_model.py b/tests/test_model.py
index 40b8944f5..dca3f30d2 100644
--- a/tests/test_model.py
+++ b/tests/test_model.py
@@ -917,7 +917,14 @@ def exploding_create_hook():
         # No exception.
         eq_(drama, drama2)
         eq_(False, is_new)
-        
+
+    def test_name_is_unique(self):
+        g1, ignore = Genre.lookup(self._db, "A Genre", autocreate=True)
+        g2, ignore = Genre.lookup(self._db, "A Genre", autocreate=True)
+        eq_(g1, g2)
+
+        assert_raises(IntegrityError, create, self._db, Genre, name="A Genre")
+
     def test_default_fiction(self):
         sf, ignore = Genre.lookup(self._db, "Science Fiction")
         nonfiction, ignore = Genre.lookup(self._db, "History")