martinshopland

<ul>
<li>Sticky posts are ordered the same way as non-sticky posts.</li>
<li>Sticky posts do not reappear on subsequent pages.</li>
<li>The first page of home will contain exactly the requested number of posts, rather than the requested number of posts plus the number of sticky posts.</li>
<li>Allows more than one page of sticky posts.</li>
</ul>
Simply injects the sticky post IDs into the actual mySQL order by clause, 
causing posts to be ordered by sticky status then by what ever order is 
specified, usually post_date DESC, and not to repeat on subsequent pages. 
I can’t actually figure out why it isn’t done like this by WP, perhaps 
earlier versions of mySQL don’t support this. WP’s default sticky ordering 
craziness is turned off by returning an empty array for the next call to 
get_option(‘sticky_posts’) which happens in WP_Query->get_posts().
There is currently a ticket awaiting review on the WordPress trac system to roll this functionality into the WordPress core: https://core.trac.wordpress.org/ticket/21986

Mend Sticky Posts

Wordpress's Sticky Posts behaviour is still incomprehensible, let's fix it.

Yslo

Empty spaces and special characters can create some problems.
<h4>Features</h4>
<ul>
<li>Improved default function <a href="https://codex.wordpress.org/Function_Reference/sanitize_file_name" rel="nofollow ugc">sanitize_file_name()</a></li>
<li>Remove latin special characters used in file name</li>
<li>Make file name lowercase</li>
</ul>

WP Sanitize File Name Plus

Sanitize file names and enhance security.

Mend Sticky Posts vs WP Sanitize File Name Plus