Path to support OPTIONS verb when using rest interface via

roundup-server. Also make sure rest interface doesn't hang when
processing OPTIONS, DELETE, PATCH which don't have a payload by
creating a CONTENT_LENGTH of 0 if these verbs are used and
CONTENT_LENGTH is missing.

Author: rouilj

CHANGES.txt

@@ -38,6 +38,11 @@ Features:
   DELETE method. We also don't allow to DELETE a whole class. Python3
   support was also fixed and we have cherry-picked two patches from the
   bugs.python.org branch in the files affected by the REST-API changes.
+- Patch to client.py and roundup-server needed by REST-API
+  code. Support OPTIONS verb and prevent hangs when processing a verb
+  other than GET that doesn't have a payload. E.G. DELETE, PATCH or
+  OPTIONS. Verbs like PUT and POST usually have payloads, so this
+  patch doesn't touch processing of these methods. (John Rouillard)
 
 Fixed:
 

roundup/cgi/client.py

@@ -363,6 +363,18 @@ def __init__(self, instance, request, env, form=None, translator=None):
 
         # see if we need to re-parse the environment for the form (eg Zope)
         if form is None:
+            # cgi.FieldStorage doesn't special case OPTIONS, DELETE or
+            # PATCH verbs. They are processed like POST. So FieldStorage
+            # hangs on these verbs trying to read posted data that
+            # will never arrive.
+            # If not defined, set CONTENT_LENGTH to 0 so it doesn't
+            # hang reading the data.
+            if self.env['REQUEST_METHOD'] in ['OPTIONS', 'DELETE', 'PATCH']:
+                if 'CONTENT_LENGTH' not in self.env:
+                    self.env['CONTENT_LENGTH'] = 0
+                    logger.debug("Setting CONTENT_LENGTH to 0 for method: %s",
+                                self.env['REQUEST_METHOD'])
+
             self.form = cgi.FieldStorage(fp=request.rfile, environ=env)
             # In some case (e.g. content-type application/xml), cgi
             # will not parse anything. Fake a list property in this case

roundup/scripts/roundup_server.py

@@ -255,7 +255,7 @@ def run_cgi(self):
                     print('EXCEPTION AT', ts)
                     traceback.print_exc()
 
-    do_GET = do_POST = do_HEAD = do_PUT = do_DELETE = do_PATCH = run_cgi
+    do_GET = do_POST = do_HEAD = do_PUT = do_DELETE = do_PATCH = do_OPTIONS = run_cgi
 
     def index(self):
         ''' Print up an index of the available trackers