How you can rewrite backslash'\'with slash'/'on Opera?

Chrome, IE, Safari, Opera has build browser rewrite backslash with slash.
But Opera 3.6.13 returns 404 error page.

# Why Firefox returns 404 error page?
RewriteCond %{REQUEST_URI} (.*)\\(.*)
RewriteRule .* %1/%2 [R=301,L]

Remarkably, that appears to become correct behavior. Backslashes aren't among the figures permitted inside a HTTP or HTTPS URL (according to RFC 1738), therefore they must be steered clear of. Observe that the RFC clearly mentions backslash being an unsafe character:

Other figures are unsafe because gateways along with other transport agents are recognized to sometimes modify such figures. These figures are "", "", "", "^", "~", "[", "]", and "`".

All unsafe figures should always be encoded inside a URL.

Quite simply, Opera does the right factor, even when it breaks pages that are improperly using backslashes (mostly from confusing URL syntax with Home windows path syntax). Other browsers are attempting to browse the page author's mind, plus they convert the backslashes to forward slashes before delivering the request whether this can be a Positive Thing is dependent on opinion.

Have you attempt to match around the steered clear of version from the backslash - %5C ?

It's Apache and FF bug, https://issues.apache.org/bugzilla/show_bug.cgi?id=35256
Hopefully it will be fixed in soon feature.

  1. AllowEncodedSlashes should certainly be "on" automatically and most likely even deprecated. ...
  2. Nowhere the RFCs is really a backslash (\) listed like a reserved character. Therefore a %5C
    should continually be decoded just like %7E is transformed into a tilde (~).

To resolve it on Apache:
add AllowEncodedSlashes On in VirtualHost httpd-vhosts.conf or httpd.conf, and .htaccess:

RewriteEngine On 
RewriteCond %{REQUEST_URI} ^(.*)\\(.*)$
RewriteRule .* %1/%2 [R=301,NC,L]