From dc6ca2cf9a99d652fdda40d11b916eb725dd9ec4 Mon Sep 17 00:00:00 2001
From: Ell <ell_se@yahoo.com>
Date: Fri, 19 Apr 2019 05:42:09 -0400
Subject: [PATCH] app: fix gimp_operation_levels_map_input() for negative
 values

... when gamma != 1
---
 app/operations/gimpoperationlevels.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/operations/gimpoperationlevels.c b/app/operations/gimpoperationlevels.c
index 63d6d21cd4..e06534473d 100644
--- a/app/operations/gimpoperationlevels.c
+++ b/app/operations/gimpoperationlevels.c
@@ -202,7 +202,7 @@ gimp_operation_levels_map_input (GimpLevelsConfig     *config,
   else
     value = (value - config->low_input[channel]);
 
-  if (config->gamma[channel] != 0.0)
+  if (config->gamma[channel] != 0.0 && value > 0.0)
     value = pow (value, 1.0 / config->gamma[channel]);
 
   return value;