fabio84

@roterdam909 No, I’m just Italian and we love long sentences, and I’m trying to explain technical issues in a language that I don’t know very well 😀

@otto: Ok, at a first try, I wasn’t able to reproduce the issue in a vanilla WordPress with only a test plugin and Simple Facebook Connect. In fact I had the issue on a WordPress installation with many plugins. On this installation, I tried enabling and disabling Simple Facebook Connect, and my fix described in the second post seemed to resolve the issue.

I have another hypothesis: maybe another plugin disables wptexturize and replaces it with another function (or gives to it another priority with the third optional parameter), so you don’t actually disable wptexturize (because another plugin already disabled it) and you add it, break something. I’ll investigate further….

As a quick and dirty solution, I have added the function _sfc_apply_filters in sfc-base.php. This function is the copy of apply_filter as in WordPress 3.5.1, but I added a condition so it executes all the filter functions except wptexturize. In sfc_base_make_excerpt I have removed the remove_filter and add_filter calls and I use _sfc_apply_filters instead of apply_filters

function _sfc_apply_filters($tag, $value) {
	global $wp_filter, $merged_filters, $wp_current_filter;

	$args = array();

	// Do 'all' actions first
	if ( isset($wp_filter['all']) ) {
		$wp_current_filter[] = $tag;
		$args = func_get_args();
		_wp_call_all_hook($args);
	}

	if ( !isset($wp_filter[$tag]) ) {
		if ( isset($wp_filter['all']) )
			array_pop($wp_current_filter);
		return $value;
	}

	if ( !isset($wp_filter['all']) )
		$wp_current_filter[] = $tag;

	// Sort
	if ( !isset( $merged_filters[ $tag ] ) ) {
		ksort($wp_filter[$tag]);
		$merged_filters[ $tag ] = true;
	}

	reset( $wp_filter[ $tag ] );

	if ( empty($args) )
		$args = func_get_args();

	do {
		foreach( (array) current($wp_filter[$tag]) as $the_ )
			if ( !(is_null($the_['function']) || $the_['function'] == 'wptexturize' ) ){
				$args[1] = $value;
				$value = call_user_func_array($the_['function'], array_slice($args, 1, (int) $the_['accepted_args']));
			}

	} while ( next($wp_filter[$tag]) !== false );

	array_pop( $wp_current_filter );

	return $value;
}

// code to create a pretty excerpt given a post object
function sfc_base_make_excerpt($post) { 

	if ( !empty($post->post_excerpt) )
		$text = $post->post_excerpt;
	else
		$text = $post->post_content;

	$text = strip_shortcodes( $text );

	// filter the excerpt or content, but without texturizing
	if ( empty($post->post_excerpt) ) {
		$text = _sfc_apply_filters('the_content', $text);
	} else {
		$text = _sfc_apply_filters('the_excerpt', $text);
	}

I hope you could rethink about the way excerpt text is generated: it seems over-complex to me at a first sight, maybe this could be done in a simpler way, but I had no time to study it and maybe all this is necessary.
Neither my fix is optimal, because _sfc_apply_filters works only with WordPress 3.5.1 and in versions with the same code for apply_filters, and may not work with other versions. So if you use a fix like mine you have to check if apply_filters changes in future WordPress versions.