w3id.org

Appearance

htaccess/no-flag-whitespace ​

Severity: error · Status: enforced · Applies to: ids/**/.htaccess

What ​

The [...] flag list at the end of a RewriteRule or RewriteCond must not contain whitespace. Flags are separated by commas and nothing else.

Why ​

Apache does not tolerate spaces in the flag list. It fails to parse the directive, and an unparseable .htaccess makes the server return 500 Internal Server Error for every URL under that directory — not just for the rule that contains the mistake.

So a single space takes the whole identifier offline, including sub-paths that have nothing to do with the broken rule.

This has needed corrective commits in this repository on several separate occasions, and instances are still present in the tree.

Wrong ​

apache
RewriteRule ^ https://example.org/ [R=302, L]
RewriteRule ^(.*)$ https://example.org/$1 [NC ,R=302,L]
RewriteRule ^vocab$ https://example.org/vocab [R=303, L]
apache
RewriteRule ^ https://example.org/ [R=302,L]
RewriteRule ^(.*)$ https://example.org/$1 [NC,R=302,L]
RewriteRule ^vocab$ https://example.org/vocab [R=303,L]

How to fix ​

Remove every space and tab between [ and ].

If your identifier is returning 500 for everything, this is the first thing to check.

How to check ​

Run w3id-check with --rule htaccess/no-flag-whitespace to check this rule on its own; without it the tool runs every rule, as the pull request checks do.

sh
node tools/check/bin/w3id-check.js --rule htaccess/no-flag-whitespace ids/my-project

Note that a plain search for whitespace between brackets is noisy — it matches prose in comments and character classes in patterns. The check reads the parsed flag argument instead, so it reports only genuine flag lists.

Testing your changes covers installing the tool, and what else is worth checking by hand.

See also ​