Translate </ to <\/ in json output to avoid issues with the string

Ben Darnell · Ben Darnell · commit f0a3d8950b49 · 2010-05-09T18:51:49.000-07:00
"&lt;/script&gt;".
diff --git a/tornado/escape.py b/tornado/escape.py
@@ -54,7 +54,13 @@ def xhtml_unescape(value):
 
 def json_encode(value):
     """JSON-encodes the given Python object."""
-    return _json_encode(value)
+    # JSON permits but does not require forward slashes to be escaped.
+    # This is useful when json data is emitted in a <script> tag
+    # in HTML, as it prevents </script> tags from prematurely terminating
+    # the javscript.  Some json libraries do this escaping by default,
+    # although python's standard library does not, so we do it here.
+    # http://stackoverflow.com/questions/1580647/json-why-are-forward-slashes-escaped
+    return _json_encode(value).replace("</", "<\\/")
 
 
 def json_decode(value):
