From d00a2d6215918736a3ca61b4a8810f91bf07309f Mon Sep 17 00:00:00 2001
From: Neil Lathwood <neil@lathwood.co.uk>
Date: Wed, 8 Mar 2017 04:15:22 +0000
Subject: [PATCH] fix: Updated set_null() function to be more useful #6030
 (#6049)

* fix: Updated set_null() function to be more useful #6030

* drop isset

* Added unit test

* change to assertNull
---
 includes/common.php           |  8 +++++---
 tests/CommonFunctionsTest.php | 11 +++++++++++
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/includes/common.php b/includes/common.php
index 293339e6bc..a7b49a899b 100644
--- a/includes/common.php
+++ b/includes/common.php
@@ -1605,10 +1605,12 @@ function uw_to_dbm($value)
  * @param int $min
  * @return null
  */
-function set_null($value, $default = null, $min = 0)
+function set_null($value, $default = null, $min = null)
 {
-    if (!isset($value) || !is_numeric($value) || (isset($min) && $value <= $min)) {
-        $value = $default;
+    if (!is_numeric($value)) {
+        return $default;
+    } elseif (isset($min) && $value < $min) {
+        return $default;
     }
     return $value;
 }
diff --git a/tests/CommonFunctionsTest.php b/tests/CommonFunctionsTest.php
index b172a26e59..ffa443b32d 100644
--- a/tests/CommonFunctionsTest.php
+++ b/tests/CommonFunctionsTest.php
@@ -84,6 +84,17 @@ class CommonFunctionsTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals('Toner, S/N CR_UM-16021314488.', safedescr($data));
     }
 
+    public function testSetNull()
+    {
+        $this->assertNull(set_null('BAD-DATA'));
+        $this->assertEquals(0, set_null(0));
+        $this->assertEquals(25, set_null(25));
+        $this->assertEquals(-25, set_null(-25));
+        $this->assertEquals(99, set_null(' ', 99));
+        $this->assertNull(set_null(-25, null, 0));
+        $this->assertEquals(2, set_null(2, 0, 2));
+    }
+
     public function testIsIp()
     {
         $this->assertTrue(is_ip('192.168.0.1'));