Hello there, i found what is causing the issue. It has to do with multibyte (UTF-8) characters, preg replace and json_encode.
If a title ends with capital greek letter pi Π (and possibly other multibyte characters) then something happens between your preg replace and the final json_encode. I guess the preg replace returns malformed characters, which in turn will make json_encode to fail to encode the final output, resulting in the ajax load more articles to fail.
the problem in: td_ajax.php near line 115
// remove whitespaces form the ajax HTML
$search = array(
'/\>[^\S ]+/s', // strip whitespaces after tags, except space
'/[^\S ]+\</s', // strip whitespaces before tags, except space
'/(\s)+/s' // shorten multiple whitespace sequences
);
$replace = array(
'>',
'<',
'\\1'
);
$buffy = preg_replace($search, $replace, $buffy);
quick fix to get rid of this thing, temporarily: just comment-out the preg_replace line so it becomes:
// $buffy = preg_replace($search, $replace, $buffy);
i had no time to investigate further due to busy schedule, but i suspect that when multibyte characters pass through preg_replace INTERNALS they are treated as non-multibyte characters, in most circumstances each multibyte character is treated as two non-multibyte characters.
so lets say multibyte “Π” character goes into preg_replace and it is becoming two characters: a weird character(1) followed by a space(2). if whatever preg_replace will do, return the characters as-is, then no problem. “Π” was seen as two characters, but its two halves(1)+(2) got returned again together so no problem. The problem is that if that “Π” is at the end of the post’s title, then it is seen as i said as two characters: a weird character(1) followed by a space(2) BUT that (2) space is matched from your pattern and gets removed. So now preg_replace returns HALF the “Π” character (only the weird (1) character since the (2) space got removed). This makes json_encode to fail due to malformed characters and of course the ajax pagination to fail.
Long-term Solutions? maybe something multibyte safe instead of preg_replace like mb-ereg-replace? Or just simply drop that trimming anyway. Why do it in the first place?
p.s. also it would be unpleasant if a multibyte characters gets split into two characters and one of them is a double quote. just saying.
