Add HTTP error messages

Browsers just show a blank page if an error occurs. You have to open the developer tools to see the HTTP status code. E.g. a user wants to download a calendar in the browser and the URL is wrong.

Some tools like curl don't show any indication of an error.

radicale/__init__.py

@@ -50,7 +50,24 @@ from . import auth, rights, storage, xmlutils
 
 VERSION = "2.0.0rc0"
 
-NOT_ALLOWED = (client.FORBIDDEN, {}, None)
+NOT_ALLOWED = (client.FORBIDDEN, {"Content-type": "text/plain"},
+               "Access to the requested resource forbidden.")
+NOT_FOUND = (client.NOT_FOUND, {"Content-type": "text/plain"},
+             "The requested resource could not be found.")
+GONE = (client.GONE, {"Content-type": "text/plain"},
+        "The requested resource is no longer available.")
+WEBDAV_PRECONDITION_FAILED = (client.CONFLICT, {"Content-type": "text/plain"},
+                              "WebDAV precondition failed.")
+PRECONDITION_FAILED = (client.PRECONDITION_FAILED,
+                       {"Content-type": "text/plain"}, "Precondition failed.")
+REQUEST_TIMEOUT = (client.REQUEST_TIMEOUT, {"Content-type": "text/plain"},
+                   "Connection timed out.")
+REQUEST_ENTITY_TOO_LARGE = (client.REQUEST_ENTITY_TOO_LARGE,
+                            {"Content-type": "text/plain"},
+                            "Request body too large.")
+REMOTE_DESTINATION = (client.BAD_GATEWAY, {"Content-type": "text/plain"},
+                      "Remote destination not supported.")
+
 DAV_HEADERS = "1, 2, 3, calendar-access, addressbook, extended-mkcol"
 
 
@@ -296,7 +313,7 @@ class Application:
 
         # If "/.well-known" is not available, clients query "/"
         if path == "/.well-known" or path.startswith("/.well-known/"):
-            return response(client.NOT_FOUND, {})
+            return response(*NOT_FOUND)
 
         if user and not storage.is_safe_path_component(user):
             # Prevent usernames like "user/calendar.ics"
@@ -326,13 +343,13 @@ class Application:
             if max_content_length and content_length > max_content_length:
                 self.logger.debug(
                     "Request body too large: %d", content_length)
-                return response(client.REQUEST_ENTITY_TOO_LARGE)
+                return response(*REQUEST_ENTITY_TOO_LARGE)
 
         if is_valid_user:
             try:
                 status, headers, answer = function(environ, path, user)
             except socket.timeout:
-                return response(client.REQUEST_TIMEOUT)
+                return response(*REQUEST_TIMEOUT)
         else:
             status, headers, answer = NOT_ALLOWED
 
@@ -342,10 +359,9 @@ class Application:
             self.logger.info("%s refused" % (user or "Anonymous user"))
             status = client.UNAUTHORIZED
             realm = self.configuration.get("server", "realm")
-            headers = {
+            headers.update ({
                 "WWW-Authenticate":
-                "Basic realm=\"%s\"" % realm}
-            answer = None
+                "Basic realm=\"%s\"" % realm})
 
         # Set content length
         if answer:
@@ -407,11 +423,11 @@ class Application:
             if not self._access(user, path, "w", item):
                 return NOT_ALLOWED
             if not item:
-                return client.GONE, {}, None
+                return GONE
             if_match = environ.get("HTTP_IF_MATCH", "*")
             if if_match not in ("*", item.etag):
                 # ETag precondition not verified, do not delete item
-                return client.PRECONDITION_FAILED, {}, None
+                return PRECONDITION_FAILED
             if isinstance(item, self.Collection):
                 answer = xmlutils.delete(path, item)
             else:
@@ -432,7 +448,7 @@ class Application:
             if not self._access(user, path, "r", item):
                 return NOT_ALLOWED
             if not item:
-                return client.NOT_FOUND, {}, None
+                return NOT_FOUND
             if isinstance(item, self.Collection):
                 collection = item
             else:
@@ -459,7 +475,7 @@ class Application:
         with self.Collection.acquire_lock("w", user):
             item = next(self.Collection.discover(path), None)
             if item:
-                return client.CONFLICT, {}, None
+                return WEBDAV_PRECONDITION_FAILED
             props = xmlutils.props_from_request(content)
             props["tag"] = "VCALENDAR"
             # TODO: use this?
@@ -475,7 +491,7 @@ class Application:
         with self.Collection.acquire_lock("w", user):
             item = next(self.Collection.discover(path), None)
             if item:
-                return client.CONFLICT, {}, None
+                return WEBDAV_PRECONDITION_FAILED
             props = xmlutils.props_from_request(content)
             self.Collection.create_collection(path, props=props)
             return client.CREATED, {}, None
@@ -485,7 +501,7 @@ class Application:
         to_url = urlparse(environ["HTTP_DESTINATION"])
         if to_url.netloc != environ["HTTP_HOST"]:
             # Remote destination server, not supported
-            return client.BAD_GATEWAY, {}, None
+            return REMOTE_DESTINATION
         if not self._access(user, path, "w"):
             return NOT_ALLOWED
         to_path = storage.sanitize_path(to_url.path)
@@ -499,20 +515,20 @@ class Application:
             if not self._access(user, to_path, "w", item):
                 return NOT_ALLOWED
             if not item:
-                return client.GONE, {}, None
+                return GONE
             if isinstance(item, self.Collection):
-                return client.CONFLICT, {}, None
+                return WEBDAV_PRECONDITION_FAILED
 
             to_item = next(self.Collection.discover(to_path), None)
             if (isinstance(to_item, self.Collection) or
                     to_item and environ.get("HTTP_OVERWRITE", "F") != "T"):
-                return client.CONFLICT, {}, None
+                return WEBDAV_PRECONDITION_FAILED
             to_parent_path = storage.sanitize_path(
                 "/%s/" % posixpath.dirname(to_path.strip("/")))
             to_collection = next(
                 self.Collection.discover(to_parent_path), None)
             if not to_collection:
-                return client.CONFLICT, {}, None
+                return WEBDAV_PRECONDITION_FAILED
             to_href = posixpath.basename(to_path.strip("/"))
             self.Collection.move(item, to_collection, to_href)
             return client.CREATED, {}, None
@@ -538,7 +554,7 @@ class Application:
             if not self._access(user, path, "r", item):
                 return NOT_ALLOWED
             if not item:
-                return client.NOT_FOUND, {}, None
+                return NOT_FOUND
             # put item back
             items = itertools.chain([item], items)
             read_items, write_items = self.collect_allowed_items(items, user)
@@ -558,7 +574,7 @@ class Application:
         with self.Collection.acquire_lock("w", user):
             item = next(self.Collection.discover(path), None)
             if not isinstance(item, self.Collection):
-                return client.CONFLICT, {}, None
+                return WEBDAV_PRECONDITION_FAILED
             headers = {"DAV": DAV_HEADERS, "Content-Type": "text/xml"}
             answer = xmlutils.proppatch(path, content, item)
             return client.MULTI_STATUS, headers, answer
@@ -589,15 +605,15 @@ class Application:
             etag = environ.get("HTTP_IF_MATCH", "")
             if not item and etag:
                 # Etag asked but no item found: item has been removed
-                return client.PRECONDITION_FAILED, {}, None
+                return PRECONDITION_FAILED
             if item and etag and item.etag != etag:
                 # Etag asked but item not matching: item has changed
-                return client.PRECONDITION_FAILED, {}, None
+                return PRECONDITION_FAILED
 
             match = environ.get("HTTP_IF_NONE_MATCH", "") == "*"
             if item and match:
                 # Creation asked but item found: item can't be replaced
-                return client.PRECONDITION_FAILED, {}, None
+                return PRECONDITION_FAILED
 
             items = list(vobject.readComponents(content or ""))
             content_type = environ.get("CONTENT_TYPE", "").split(";")[0]
@@ -625,7 +641,7 @@ class Application:
             if not self._access(user, path, "w", item):
                 return NOT_ALLOWED
             if not item:
-                return client.NOT_FOUND, {}, None
+                return NOT_FOUND
             if isinstance(item, self.Collection):
                 collection = item
             else: