From b29fb0b87004d9eb269eafaa041b48f2d833e68d Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Thu, 7 May 2020 11:26:54 +0100
Subject: [PATCH] Added ZLIB as a build depdency to PNG plugin build

---
 src/osgPlugins/CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/osgPlugins/CMakeLists.txt b/src/osgPlugins/CMakeLists.txt
index 4982847ce..277dbebd5 100644
--- a/src/osgPlugins/CMakeLists.txt
+++ b/src/osgPlugins/CMakeLists.txt
@@ -111,7 +111,7 @@ ENDIF()
 IF(GIFLIB_FOUND)
     ADD_PLUGIN_DIRECTORY(gif)
 ENDIF()
-IF(PNG_FOUND)
+IF(PNG_FOUND AND ZLIB_FOUND)
     ADD_PLUGIN_DIRECTORY(png)
 ENDIF()
 IF(TIFF_FOUND)