Redirecting SEO rewritten url - .htaccess

Question

I'm using these rewrite rules to go from dynamic urls to static ones.
RewriteEngine On
RewriteRule ^songs/album/([^/]*)\.html$ /index.html?album=$1 [L,QSA]
Old url: http://example.com/index.html?album=rockstar
New url: http://example.com/songs/album/rockstar.html
But if I try to redirect old url to new url, it doesn't work
RedirectMatch 301 ^/index.html?album=(.*)\$ http://example.com/songs/album/$1.html
Any ideas?

Answer 1

The RedirectMatch directive in mod_alias won't match against the query string, only the /index.html part. You'd need to use a RewriteCond ${QUERY_STRING} <regexp> to match against it. But if you redirect like that you're going to cause a loop because the URI is put through the rewrite engine until the URI comes out unchanged:
Person types http://example.com/index.html?album=rockstar into their URL address bar
browser gets redirected to http://example.com/songs/album/rockstar.html
mod rewrite sees /songs/album/rockstar.html and rewrites it to /index.html?album=rockstar
the redirect rule successfully matches against /index.html?album=rockstar
repeat from step 2.
You need to make sure to only redirect if the actual request was for /index.html?album=rockstar, and not when it's been through the rewrite engine:
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /index\.html\?album=(.+)\ HTTP
RewriteRule ^index\.html$ http://example.com/songs/album/%1.html? [R=301,L]
The %{THE_REQUEST} is the actual HTTP request, and not the rewritten URI. The %1 is a backreference to a match in a previous RewriteCond and the ? at the end of the redirect URL tells the RewriteRule not to append the query string to the end.