--- /dev/null
+From 9f734b13f4ea062af98652c4c7678f667d2d85c7 Mon Sep 17 00:00:00 2001
+From: David Callu <callu.david@gmail.com>
+Date: Thu, 4 Jul 2019 15:15:53 +0200
+Subject: [PATCH] cmake: Use the correct ZLIB_* variable names
+
+ZLIB_LIBRARIES and ZLIB_INCLUDE_DIRS are the official cmake variable
+names.
+---
+ CMakeLists.txt | 15 ++++++++-------
+ 1 file changed, 8 insertions(+), 7 deletions(-)
+
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -40,7 +40,7 @@ option(PNG_BUILD_ZLIB "Custom zlib Locat
+
+ if(NOT PNG_BUILD_ZLIB)
+ find_package(ZLIB REQUIRED)
+- include_directories(${ZLIB_INCLUDE_DIR})
++ include_directories(${ZLIB_INCLUDE_DIRS})
+ endif()
+
+ if(UNIX AND NOT APPLE AND NOT BEOS AND NOT HAIKU)
+@@ -523,7 +523,7 @@ if(PNG_DEBUG)
+ endif()
+
+ # NOW BUILD OUR TARGET
+-include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${ZLIB_INCLUDE_DIR})
++include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${ZLIB_INCLUDE_DIRS})
+
+ unset(PNG_LIB_TARGETS)
+
+@@ -537,7 +537,7 @@ if(PNG_SHARED)
+ set_target_properties(png PROPERTIES PREFIX "lib")
+ set_target_properties(png PROPERTIES IMPORT_PREFIX "lib")
+ endif()
+- target_link_libraries(png ${ZLIB_LIBRARY} ${M_LIBRARY})
++ target_link_libraries(png ${ZLIB_LIBRARIES} ${M_LIBRARY})
+
+ if(UNIX AND AWK)
+ if(HAVE_LD_VERSION_SCRIPT)
+@@ -572,7 +572,7 @@ if(PNG_STATIC)
+ # msvc does not append 'lib' - do it here to have consistent name
+ set_target_properties(png_static PROPERTIES PREFIX "lib")
+ endif()
+- target_link_libraries(png_static ${ZLIB_LIBRARY} ${M_LIBRARY})
++ target_link_libraries(png_static ${ZLIB_LIBRARIES} ${M_LIBRARY})
+ endif()
+
+ if(PNG_FRAMEWORK)
+@@ -589,7 +589,7 @@ if(PNG_FRAMEWORK)
+ XCODE_ATTRIBUTE_INSTALL_PATH "@rpath"
+ PUBLIC_HEADER "${libpng_public_hdrs}"
+ OUTPUT_NAME png)
+- target_link_libraries(png_framework ${ZLIB_LIBRARY} ${M_LIBRARY})
++ target_link_libraries(png_framework ${ZLIB_LIBRARIES} ${M_LIBRARY})
+ endif()
+
+ if(NOT PNG_LIB_TARGETS)
+@@ -754,7 +754,7 @@ if(PNG_SHARED AND PNG_EXECUTABLES)
+ set(PNG_BIN_TARGETS pngfix)
+
+ add_executable(png-fix-itxt ${png_fix_itxt_sources})
+- target_link_libraries(png-fix-itxt ${ZLIB_LIBRARY} ${M_LIBRARY})
++ target_link_libraries(png-fix-itxt ${ZLIB_LIBRARIES} ${M_LIBRARY})
+ list(APPEND PNG_BIN_TARGETS png-fix-itxt)
+ endif()
+
--- /dev/null
+From dbe3e0c43e549a1602286144d94b0666549b18e6 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Cristian=20Rodr=C3=ADguez?= <crrodriguez@opensuse.org>
+Date: Mon, 19 Mar 2018 12:41:47 -0300
+Subject: [PATCH] libpng.pc.in: zlib dependency is private
+
+zlib should be injected only when pkgconfig is ran with the --static
+option.
+---
+ libpng.pc.in | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/libpng.pc.in
++++ b/libpng.pc.in
+@@ -6,7 +6,7 @@ includedir=@includedir@/libpng@PNGLIB_MA
+ Name: libpng
+ Description: Loads and saves PNG files
+ Version: @PNGLIB_VERSION@
+-Requires: zlib
++Requires.private: zlib
+ Libs: -L${libdir} -lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
+ Libs.private: @LIBS@
+ Cflags: -I${includedir}