Fix GH-158: Replace empty() with strict string comparison for sdesc/ldesc

Both sdesc and ldesc are always initialized as "" in storeInfo() and
populated with htmlentities(trim(...)) results, so they are always
strings. Using empty() is overly broad here since it would also treat
a legitimate "0" value as empty. Replace with === "" for precision.

The third occurrence in Package/PEAR/Web.php was already removed in
commit 53f9afe.

Author: lacatoire

phpdotnet/phd/Index.php

@@ -358,7 +358,7 @@ public function format_long_desc($open, $name, $attrs, $props) {
             return;
         }
         $this->inLongDesc = false;
-        if (empty($this->nfo[$this->currentid]["ldesc"])) {
+        if ($this->nfo[$this->currentid]["ldesc"] === "") {
             $this->nfo[$this->currentid]["ldesc"] = htmlentities(trim($this->currentLongDesc), ENT_COMPAT, "UTF-8");
         }
     }
@@ -370,7 +370,7 @@ public function format_short_desc($open, $name, $attrs, $props) {
         }
         $this->inShortDesc = false;
         $s = htmlentities(trim($this->currentShortDesc), ENT_COMPAT, "UTF-8");
-        if (empty($this->nfo[$this->currentid]["sdesc"])) {
+        if ($this->nfo[$this->currentid]["sdesc"] === "") {
             $this->nfo[$this->currentid]["sdesc"] = $s;
         } else {
             if (!is_array($this->nfo[$this->currentid]["sdesc"])) {