From ebdeb231ebc6da619720a016e464b483967374d5 Mon Sep 17 00:00:00 2001
From: Mark Baker <mark@lange.demon.co.uk>
Date: Tue, 15 Jun 2021 22:35:04 +0200
Subject: [PATCH] Allow negative interest rate in PPMT() Financial function
 (#2164)

---
 .../Calculation/Financial/CashFlow/CashFlowValidations.php    | 3 ---
 tests/data/Calculation/Financial/PPMT.php                     | 4 ++++
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/PhpSpreadsheet/Calculation/Financial/CashFlow/CashFlowValidations.php b/src/PhpSpreadsheet/Calculation/Financial/CashFlow/CashFlowValidations.php
index fde68860..e4c8a3a4 100644
--- a/src/PhpSpreadsheet/Calculation/Financial/CashFlow/CashFlowValidations.php
+++ b/src/PhpSpreadsheet/Calculation/Financial/CashFlow/CashFlowValidations.php
@@ -15,9 +15,6 @@ class CashFlowValidations extends FinancialValidations
     public static function validateRate($rate): float
     {
         $rate = self::validateFloat($rate);
-        if ($rate < 0.0) {
-            throw new Exception(Functions::NAN());
-        }
 
         return $rate;
     }
diff --git a/tests/data/Calculation/Financial/PPMT.php b/tests/data/Calculation/Financial/PPMT.php
index c56626f9..b2f92011 100644
--- a/tests/data/Calculation/Financial/PPMT.php
+++ b/tests/data/Calculation/Financial/PPMT.php
@@ -5,6 +5,10 @@ return [
         -75.623186008367,
         [0.10 / 12, 1, 2 * 12, 2000],
     ],
+    [
+        -91.597714484189,
+        [-0.10 / 12, 1, 2 * 12, 2000],
+    ],
     [
         -27598.053462421,
         [0.08, 10, 10, 200000],