mingw_cross_toolchain.cmake: set the MINGW variable to True

Setting MINGW to True is important to let cmake set some variables such
as CMAKE_FIND_LIBRARY_PREFIXES and CMAKE_FIND_LIBRARY_SUFFIXES from
Platform/Windows-GNU.cmake

I wasted a lot of time on this with find_library() not finding libav
libraries compiled for MingW whith the ".dll.a" suffix.

diff --git a/cmake_modules/mingw_cross_toolchain.cmake b/cmake_modules/mingw_cross_toolchain.cmake
index 32ef5ab..e3ae052 100644 (file)
--- a/cmake_modules/mingw_cross_toolchain.cmake
+++ b/cmake_modules/mingw_cross_toolchain.cmake
@@ -7,3 +7,8 @@ ENDIF()
 CMAKE_FORCE_C_COMPILER(${GNU_HOST}-gcc GNU)
 # CMake doesn't automatically look for prefixed 'windres', do it manually:
 SET(CMAKE_RC_COMPILER ${GNU_HOST}-windres)
+
+# The following is important to let cmake set some variables such as
+# CMAKE_FIND_LIBRARY_PREFIXES and CMAKE_FIND_LIBRARY_SUFFIXES from
+# Platform/Windows-GNU.cmake
+SET(MINGW True)