Fix #3410: return code in :confval:release breaks html search

CHANGES

@@ -27,6 +27,7 @@ Bugs fixed
   gets wrong PDF page dimensions
 * #3399: quickstart: conf.py was not overwritten by template
 * #3366: option directive does not allow punctuations
+* #3410: return code in :confval:`release` breaks html search
 
 Testing
 --------

sphinx/builders/html.py

@@ -10,6 +10,7 @@
 """
 
 import os
+import re
 import sys
 import zlib
 import codecs
@@ -50,6 +51,8 @@ INVENTORY_FILENAME = 'objects.inv'
 #: the filename for the "last build" file (for serializing builders)
 LAST_BUILD_FILENAME = 'last_build'
 
+return_codes_re = re.compile('[\r\n]+')
+
 
 def get_stable_hash(obj):
     """
@@ -329,7 +332,7 @@ class StandaloneHTMLBuilder(Builder):
         self.globalcontext = dict(
             embedded = self.embedded,
             project = self.config.project,
-            release = self.config.release,
+            release = return_codes_re.sub('', self.config.release),
             version = self.config.version,
             last_updated = self.last_updated,
             copyright = self.config.copyright,