Problem

Opening a page with a title that contains special characters leads to a system error.  For example: [ABC] Hello

The following appears on the screen as well as in  atlassian-confluence.log

Caused by: java.net.URISyntaxException: Illegal character in path at index 14: /display/<SPACEKEY>/[ABC]+HELLO
	at java.net.URI$Parser.fail(URI.java:2848)
	at java.net.URI$Parser.checkChars(URI.java:3021)
	at java.net.URI$Parser.parseHierarchical(URI.java:3105)
	at java.net.URI$Parser.parse(URI.java:3063)
	at java.net.URI.<init>(URI.java:588)
	at com.github.kristofa.brave.servlet.ServletHttpServerRequest.getUri(ServletHttpServerRequest.java:25)
	... 49 more

Diagnosis

Environment

Confluence is configured with an Apache Reverse Proxy, an Apache Reverse Proxy Using the AJP Protocol OR NGINX.

Cause

While the handling of special characters in the page title worked for the proxy configuration while running Confluence 5.8.x, the same configuration no longer works in version 5.10.x or higher.

Workaround

Apache Reverse Proxy Using the AJP Protocol

In the httpd.conf.local file, the following JkOption will most likely be present:

JkOptions +ForwardKeySize +ForwardURICompat -ForwardDirectories

The +ForwardURICompat parameter needs to be changed for Confluence 5.10.x  to +ForwardURICompatUnparsed.  For example:

JkOptions +ForwardKeySize +ForwardURICompatUnparsed -ForwardDirectories

Apache Reverse Proxy

For an Apache reverse proxy, ensure that the following is present:

ProxyPass /confluence http://localhost:8090/confluence nocanon

NGINX

For NGINX, simply edit the nginx.conf file by adding $request_uri; to the proxy_pass directive (as long as the location and context path are the same).  For example: 

location /<context-path> {

    proxy_set_header X-Forwarded-Host $host;
    proxy_set_header X-Forwarded-Server $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; 

proxy_pass http://<base-url>/<context-path>$request_uri;
}

If this doesn't work or returns an error (we've seen some users receive 502 errors with the above change), then please use the following:

location /<context-path> {

    proxy_set_header X-Forwarded-Host $host;
    proxy_set_header X-Forwarded-Server $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; 
 
if ($request_uri ~* "/<context-path>(/.*)") { 
	proxy_pass http://<base-url>/<context-path>$1; break; 
}

proxy_pass http://<base-url>/<context-path>;
}

In all cases, the proxy will need to be restarted to pick up these changes.

Note

Caveat: When the same Nginx is used by Jira, this configuration will affect Jira's configuration for the OAuth2 - Configure an outgoing link as the format of the Request is <Jira base URL>/rest/oauth2-client/latest/config/get-redirect-uri/?authorizationEndpoint=https://login.microsoftonline.com/common/oauth2/v2.0/authorize