cmake: clean cached INTERNAL variable used for 3rdparty deps

cmake/OpenCVFindLibsGrfmt.cmake

@@ -6,6 +6,7 @@
 if(BUILD_ZLIB)
   ocv_clear_vars(ZLIB_FOUND)
 else()
+  ocv_clear_internal_cache_vars(ZLIB_LIBRARY ZLIB_INCLUDE_DIR)
   find_package(ZLIB "${MIN_VER_ZLIB}")
   if(ZLIB_FOUND AND ANDROID)
     if(ZLIB_LIBRARIES MATCHES "/usr/(lib|lib32|lib64)/libz.so$")
@@ -31,11 +32,12 @@ if(WITH_JPEG)
   if(BUILD_JPEG)
     ocv_clear_vars(JPEG_FOUND)
   else()
+    ocv_clear_internal_cache_vars(JPEG_LIBRARY JPEG_INCLUDE_DIR)
     include(FindJPEG)
   endif()
 
   if(NOT JPEG_FOUND)
-    ocv_clear_vars(JPEG_LIBRARY JPEG_LIBRARIES JPEG_INCLUDE_DIR)
+    ocv_clear_vars(JPEG_LIBRARY JPEG_INCLUDE_DIR)
 
     if(NOT BUILD_JPEG_TURBO_DISABLE)
       set(JPEG_LIBRARY libjpeg-turbo CACHE INTERNAL "")
@@ -76,6 +78,7 @@ if(WITH_TIFF)
   if(BUILD_TIFF)
     ocv_clear_vars(TIFF_FOUND)
   else()
+    ocv_clear_internal_cache_vars(TIFF_LIBRARY TIFF_INCLUDE_DIR)
     include(FindTIFF)
     if(TIFF_FOUND)
       ocv_parse_header("${TIFF_INCLUDE_DIR}/tiff.h" TIFF_VERSION_LINES TIFF_VERSION_CLASSIC TIFF_VERSION_BIG TIFF_VERSION TIFF_BIGTIFF_VERSION)
@@ -119,6 +122,7 @@ if(WITH_WEBP)
   if(BUILD_WEBP)
     ocv_clear_vars(WEBP_FOUND WEBP_LIBRARY WEBP_LIBRARIES WEBP_INCLUDE_DIR)
   else()
+    ocv_clear_internal_cache_vars(WEBP_LIBRARY WEBP_INCLUDE_DIR)
     include(cmake/OpenCVFindWebP.cmake)
     if(WEBP_FOUND)
       set(HAVE_WEBP 1)
@@ -184,6 +188,7 @@ if(WITH_PNG)
   if(BUILD_PNG)
     ocv_clear_vars(PNG_FOUND)
   else()
+    ocv_clear_internal_cache_vars(PNG_LIBRARY PNG_INCLUDE_DIR)
     include(FindPNG)
     if(PNG_FOUND)
       include(CheckIncludeFile)
@@ -215,6 +220,7 @@ endif()
 if(WITH_OPENEXR)
   ocv_clear_vars(HAVE_OPENEXR)
   if(NOT BUILD_OPENEXR)
+    ocv_clear_internal_cache_vars(OPENEXR_INCLUDE_PATHS OPENEXR_LIBRARIES OPENEXR_ILMIMF_LIBRARY OPENEXR_VERSION)
     include("${OpenCV_SOURCE_DIR}/cmake/OpenCVFindOpenEXR.cmake")
   endif()