Fixes presence of empty tags for private tags and in search results

  * Private tags: make sure empty tags are properly filtered
  * Search results:
    * Use preg_split instead of function combination
    * Add normalize_spaces to remove extra whitespaces displaying empty tags search

2 files changed, 14 insertions, 1 deletions

diff --git a/application/LinkFilter.php b/application/LinkFilter.php
index daa6d9cc..57ebfd5c 100644
--- a/application/LinkFilter.php
+++ b/application/LinkFilter.php
@@ -348,7 +348,7 @@ class LinkFilter
         $tagsOut = $casesensitive ? $tags : mb_convert_case($tags, MB_CASE_LOWER, 'UTF-8');
         $tagsOut = str_replace(',', ' ', $tagsOut);
 
-        return array_values(array_filter(explode(' ', trim($tagsOut)), 'strlen'));
+        return preg_split('/\s+/', $tagsOut, -1, PREG_SPLIT_NO_EMPTY);
     }
 }
 
diff --git a/application/Utils.php b/application/Utils.php
index 62902341..35d65224 100644
--- a/application/Utils.php
+++ b/application/Utils.php
@@ -257,3 +257,16 @@ function generate_api_secret($username, $salt)
 
     return str_shuffle(substr(hash_hmac('sha512', uniqid($salt), $username), 10, 12));
 }
+
+/**
+ * Trim string, replace sequences of whitespaces by a single space.
+ * PHP equivalent to `normalize-space` XSLT function.
+ *
+ * @param string $string Input string.
+ *
+ * @return mixed Normalized string.
+ */
+function normalize_spaces($string)
+{
+    return preg_replace('/\s{2,}/', ' ', trim($string));
+}