The code developed so far (resembling the buddyPress Forum experience):
...
<span id="topic_posts"><?php topic_posts_link(); ?>, </span>
<span id="topic_voices"><?php printf( '%s voices', bb_get_topic_voices() ); ?></span>
<span><?php if ( 1 < get_topic_posts() ) : ?>
<?php printf(__('- <a href="%1$s">Latest reply</a> from '),attribute_escape( get_topic_last_post_link()) ) ?>
<a href="<?php bb_option('uri'); ?>profile.php?id=<?php echo (sanitize_user(get_topic_last_poster(),true)); ?>"><?php echo get_topic_last_poster(); ?></a>
<?php endif; ?>
</span>
does only generate an “User not found.” error with:
..../profile.php?id=Test%20User
get_user_profile_link( $topic->topic_poster ), rather than all that sanitize/echo stuff. Can’t check it 100% since my test server is dead, but that should be right I think.
Appreciating your help – but I’m looking for linking to the profile of the last poster – not the last topic->poster
I already spent some hours on searching the forum & the web, but there seems no feasible solution for the %20 issue.
Oh, that’s get_user_profile_link( $topic->topic_last_poster ) then 
it seems that usernames don’t contain spaces (only the display name does), the username is converted to using a – instead of any invalid characters
Solution found – bb_user_nicename_sanitize()– needs peer review because of possible side-effects (UTF8 etc.)
<span><?php if ( 1 < get_topic_posts() ) : ?>
<?php printf(__('- <a href="%1$s">Latest reply</a> from '),attribute_escape( get_topic_last_post_link()) ) ?>
<a href="<?php bb_option('uri'); ?>profile.php?id=<?php echo (bb_user_nicename_sanitize(get_topic_last_poster(),50)); ?>"><?php echo get_topic_last_poster(); ?></a>
<?php endif; ?>
</span>
PS: A look into one’s database via phpadmin produces the right insights …
I find looking at a bbPress install database pretty unnerving with all the relational IDs around the place 
But it’s a nice place to look for nice_name’s … 
)
Thanks for posting the solution also, I was looking at my codes if I could get a solution, but I couldn’t, when I looked back at this topic, I saw the solution already posted.
I’ve been using this code for a while now, untill I discovered in my Google webmaster tools account that it’s giving some broken URL’s. Appearantly this code only works when you have pretty URL’s turned on — which is not in my case.
Is there a way to link it to profile id’s instead of profile names? (e.g. domain/profile.php?id=2 instead of domain/username)
Thanks in advance.
@chandersbs.
See if this other code works for you.
<a href="<?php echo get_user_profile_link(bb_get_user_id($topic->topic_last_poster)); ?>"><?php topic_last_poster(); ?></a>
I tried it with the three permalink types without problem.
@matveb thanks that worked.
