Merge branch 'empty-multi' of https://bitbucket.org/wichert/dogpile.cache/branch/empty-multi into pr/20

Fixes #58

3 files changed, 23 insertions, 0 deletions

diff --git a/docs/build/changelog.rst b/docs/build/changelog.rst
index 25f32d9..1d33bf4 100644
--- a/docs/build/changelog.rst
+++ b/docs/build/changelog.rst
@@ -5,6 +5,15 @@ Changelog
     :version: 0.5.4
 
     .. change::
+      :tags: bug
+      :tickets: 58
+      :pullreq: 20
+
+      Fixed bug where calling :meth:`.CacheRegion.get_multi` or
+      :meth:`.CacheRegion.set_multi` with an empty list would cause failures
+      based on backend.  Pull request courtesy Wichert Akkerman.
+
+    .. change::
       :tags: feature
       :pullreq: 17
 
diff --git a/dogpile/cache/region.py b/dogpile/cache/region.py
index e7d152b..39cfd0a 100644
--- a/dogpile/cache/region.py
+++ b/dogpile/cache/region.py
@@ -503,6 +503,9 @@ class CacheRegion(object):
         .. versionadded:: 0.5.0
 
         """
+        if not keys:
+            return []
+
         if self.key_mangler:
             keys = list(map(lambda key: self.key_mangler(key), keys))
 
@@ -781,6 +784,8 @@ class CacheRegion(object):
         .. versionadded:: 0.5.0
 
         """
+        if not mapping:
+            return
 
         if self.key_mangler:
             mapping = dict((self.key_mangler(k), self._value(v))
diff --git a/tests/cache/_fixtures.py b/tests/cache/_fixtures.py
index 0b6e2a0..f12c366 100644
--- a/tests/cache/_fixtures.py
+++ b/tests/cache/_fixtures.py
@@ -101,6 +101,10 @@ class _GenericBackendTest(_GenericBackendFixture, TestCase):
         eq_(values['key2'], reg.get('key2'))
         eq_(values['key3'], reg.get('key3'))
 
+    def test_region_set_zero_multiple_values(self):
+        reg = self._region()
+        reg.set_multi({})
+
     def test_region_get_multiple_values(self):
         reg = self._region()
         key1 = 'value1'
@@ -126,6 +130,11 @@ class _GenericBackendTest(_GenericBackendFixture, TestCase):
             ]
         )
 
+    def test_region_get_empty_multiple(self):
+        reg = self._region()
+        reg_values = reg.get_multi([])
+        eq_(reg_values, [])
+
     def test_region_delete_multiple(self):
         reg = self._region()
         values = {'key1': 'value1', 'key2': 'value2', 'key3': 'value3'}