Malformed link header causes WAIT to display

[machawk1]

See #307 and http://matkelly.com/temp/aac.txt

Some server config is causing the response header Link: <http://purl.org/memento/timegate/(null)://(null)(null)>;rel=timegate. Mink chokes on this when the URI cannot be retrieved citing 502 Bad Gateway. It ought to be more resilient and fail a little more gracefully or, like other instances, disregard the header if wonky or invalid.

[machawk1]

This is happening because of an interesting .htaccess file in the /temp/ folder at matkelly.com:

RewriteRule ^/(.*) - [E=ORIGQRY:]
RewriteCond %{QUERY_STRING} .+
RewriteRule ^/(.*) - [E=ORIGQRY:?%{QUERY_STRING}]
RewriteRule ^/(.*) - [E=ORIGPROTO:http]
RewriteCond %{HTTPS} on
RewriteRule ^/(.*) - [E=ORIGPROTO:https]
Header always set Link "<http://purl.org/memento/timegate/%{ORIGPROTO}e://%{ORIGURI}e%{ORIGQRY}e>;rel=timegate"

This looks like it was borrowed from somewhere...probably from "how to enable Memento on your Apache server" docs from mementoweb.

EDIT: This htaccess is recursively applied as well. See curl -I http://matkelly.com/temp/tmp2/aad.txt.

[machawk1]

content.js sends a message in displayUIBasedOnContext() with the method findTMURI and value of the TimeGate URI. This message is received in mink.js and findTMURI() is called, which contains an AJAX request. On failure, because of the (a)synchronicity and loss of communication channel, a failure in this AJAX function cannot instruct the original caller to proceed with another variation.

[machawk1]

Much of this is fixed in 2969ad7 (issue-308 branch). On encountering a bad Link header value, after failing to query the TG, the Link header is removed and the same logic used to send the request for the URI-R to the aggregator.

This is not yet complete. In iterating through the headers, using JavaScript's delete to remove the attribute leaves a null value in the member. When reading these values over again in secondary processing, I had to manually check for this. I would like to see this better handled at the source before merging it in.

[machawk1]

Perhaps the remaining null is due to a pre-existing value not being cleared and some sort of "placeholder" remaining. When logging where setting the value, the attribute is not present. When reading the value, the null displays when iterating through each attribute after reading from localStorage.