Fixed rcube_imap_generic::uncompressMessageSet() result when argument is empty. Added tests.

program/include/rcube_imap_generic.php

@@ -3530,6 +3530,10 @@ class rcube_imap_generic
      */
     static function uncompressMessageSet($messages)
     {
+        if (empty($messages)) {
+            return array();
+        }
+
         $result   = array();
         $messages = explode(',', $messages);
 
@@ -3538,7 +3542,7 @@ class rcube_imap_generic
             $max   = max($items[0], $items[1]);
 
             for ($x=$items[0]; $x<=$max; $x++) {
-                $result[] = $x;
+                $result[] = (int)$x;
             }
             unset($messages[$idx]);
         }

tests/Framework/ImapGeneric.php

@@ -17,4 +17,22 @@ class Framework_ImapGeneric extends PHPUnit_Framework_TestCase
 
         $this->assertInstanceOf('rcube_imap_generic', $object, "Class constructor");
     }
+
+    /**
+     * Test for uncompressMessageSet
+     */
+    function test_uncompressMessageSet()
+    {
+        $result = rcube_imap_generic::uncompressMessageSet(null);
+        $this->assertSame(array(), $result);
+        $this->assertCount(0, $result);
+
+        $result = rcube_imap_generic::uncompressMessageSet('1');
+        $this->assertSame(array(1), $result);
+        $this->assertCount(1, $result);
+
+        $result = rcube_imap_generic::uncompressMessageSet('1:3');
+        $this->assertSame(array(1, 2, 3), $result);
+        $this->assertCount(3, $result);
+    }
 }