Index: wp-admin/includes/class-pclzip.php
===================================================================
--- wp-admin/includes/class-pclzip.php	(revision 56808)
+++ wp-admin/includes/class-pclzip.php	(working copy)
@@ -376,7 +376,7 @@
     // ----- Reformat the string list
     if (sizeof($v_string_list) != 0) {
       foreach ($v_string_list as $v_string) {
-        if ($v_string != '') {
+        if ($v_string !== '') {
           $v_att_list[][PCLZIP_ATT_FILE_NAME] = $v_string;
         }
         else {
@@ -772,7 +772,7 @@
         }
         if (isset($v_options[PCLZIP_OPT_ADD_PATH])) {
           // ----- Check for '/' in last path char
-          if ((strlen($v_path) > 0) && (substr($v_path, -1) != '/')) {
+          if ((strlen($v_path) > 0) && (substr($v_path, -1) !== '/')) {
             $v_path .= '/';
           }
           $v_path .= $v_options[PCLZIP_OPT_ADD_PATH];
@@ -928,7 +928,7 @@
         }
         if (isset($v_options[PCLZIP_OPT_ADD_PATH])) {
           // ----- Check for '/' in last path char
-          if ((strlen($v_path) > 0) && (substr($v_path, -1) != '/')) {
+          if ((strlen($v_path) > 0) && (substr($v_path, -1) !== '/')) {
             $v_path .= '/';
           }
           $v_path .= $v_options[PCLZIP_OPT_ADD_PATH];
@@ -1526,7 +1526,7 @@
 
           // ----- Get the value
           if (   is_string($p_options_list[$i+1])
-              && ($p_options_list[$i+1] != '')) {
+              && ($p_options_list[$i+1] !== '')) {
             $v_result_list[$p_options_list[$i]] = PclZipUtilTranslateWinPath($p_options_list[$i+1], FALSE);
             $i++;
           }
@@ -2077,7 +2077,7 @@
             // files/sub-folders also change
             if (($v_descr['stored_filename'] != $v_descr['filename'])
                  && (!isset($p_options[PCLZIP_OPT_REMOVE_ALL_PATH]))) {
-              if ($v_descr['stored_filename'] != '') {
+              if ($v_descr['stored_filename'] !== '') {
                 $v_dirlist_descr[$v_dirlist_nb]['new_full_name'] = $v_descr['stored_filename'].'/'.$v_item_handler;
               }
               else {
@@ -2487,7 +2487,7 @@
       }
 
       // ----- Check the filename
-      if (   ($p_filedescr_list[$j]['type'] != 'virtual_file')
+      if (   ($p_filedescr_list[$j]['type'] !== 'virtual_file')
           && (!file_exists($p_filedescr_list[$j]['filename']))) {
         PclZip::privErrorLog(PCLZIP_ERR_MISSING_FILE, "File '".$p_filedescr_list[$j]['filename']."' does not exist");
         return PclZip::errorCode();
@@ -2755,7 +2755,7 @@
       // ----- Look for a directory
       else if ($p_filedescr['type'] == 'folder') {
         // ----- Look for directory last '/'
-        if (@substr($p_header['stored_filename'], -1) != '/') {
+        if (@substr($p_header['stored_filename'], -1) !== '/') {
           $p_header['stored_filename'] .= '/';
         }
 
@@ -2955,7 +2955,7 @@
       if (isset($p_filedescr['new_short_name'])) {
         $v_path_info = pathinfo($p_filename);
         $v_dir = '';
-        if ($v_path_info['dirname'] != '') {
+        if ($v_path_info['dirname'] !== '') {
           $v_dir = $v_path_info['dirname'].'/';
         }
         $v_stored_filename = $v_dir.$p_filedescr['new_short_name'];
@@ -2971,7 +2971,7 @@
       }
       // ----- Look for partial path remove
       else if ($p_remove_dir != "") {
-        if (substr($p_remove_dir, -1) != '/')
+        if (substr($p_remove_dir, -1) !== '/')
           $p_remove_dir .= "/";
 
         if (   (substr($p_filename, 0, 2) == "./")
@@ -3305,7 +3305,7 @@
     }
 
     // ----- Look for path to remove format (should end by /)
-    if (($p_remove_path != "") && (substr($p_remove_path, -1) != '/'))
+    if (($p_remove_path != "") && (substr($p_remove_path, -1) !== '/'))
     {
       $p_remove_path .= '/';
     }
@@ -3482,7 +3482,7 @@
     }
 
       // ----- Look for real extraction
-      if (($v_extract) && ($v_header['status'] != 'ok')) {
+      if (($v_extract) && ($v_header['status'] !== 'ok')) {
           $v_result = $this->privConvertHeader2FileInfo($v_header,
 		                                        $p_file_list[$v_nb_extracted++]);
           if ($v_result != 1) {
@@ -3675,7 +3675,7 @@
     }
 
     // ----- Add the path
-    if ($p_path != '') {
+    if ($p_path !== '') {
       $p_entry['filename'] = $p_path."/".$p_entry['filename'];
     }
 
@@ -5548,7 +5548,7 @@
       }
 
       // ----- Compare the items
-      if (($v_list_dir[$i] != $v_list_path[$j]) && ($v_list_dir[$i] != '') && ( $v_list_path[$j] != ''))  {
+      if (($v_list_dir[$i] != $v_list_path[$j]) && ($v_list_dir[$i] !== '') && ( $v_list_path[$j] !== ''))  {
         $v_result = 0;
       }