Better handle libintl dependencies

CMakeLists.txt

@@ -104,6 +104,37 @@ if(ENABLE_NLS)
   find_package(Intl REQUIRED)
   include_directories(${Intl_INCLUDE_DIRS})
   link_libraries(${Intl_LIBRARIES})
+
+  # begin static libintl support
+  # libintl.a may depend on libiconv.a and libcharset.a
+  # this is the case of vcpkg + mingw, for example
+  macro(try_compile_intl)
+    set(_argv ${ARGV})
+    try_compile(INTLLIB ${CMAKE_BINARY_DIR}
+                "${CMAKE_SOURCE_DIR}/checks/intl.cpp"
+                LINK_LIBRARIES ${_argv}
+                CMAKE_FLAGS "-DINCLUDE_DIRECTORIES=${Intl_INCLUDE_DIRS}")
+  endmacro()
+
+  try_compile_intl(${Intl_LIBRARIES})
+  if (NOT INTLLIB)
+    message(STATUS "Checking for libiconv and libcharset dependencies of libintl")
+    find_package(Iconv REQUIRED)
+    link_libraries(${Iconv_LIBRARIES})
+
+    try_compile_intl(${Intl_LIBRARIES} ${Iconv_LIBRARIES})
+    if (NOT INTLLIB)
+      find_library(Charset_LIBRARY NAMES libcharset charset HINTS Charset_DIR)
+      try_compile_intl(${Intl_LIBRARIES} ${Iconv_LIBRARIES} ${Charset_LIBRARY})
+      if (NOT INTLLIB)
+        message(FATAL_ERROR "LibIntl has unknown dependencies")
+      else()
+        link_libraries(${Charset_LIBRARY})
+      endif()
+    endif()
+  endif()
+  # end static libintl support
+
   add_definitions(-DENABLE_NLS)
 else()
   message(STATUS "NLS is disabled. Not looking for gettext and libintl.")

checks/intl.cpp

@@ -0,0 +1,7 @@
+#include <libintl.h>
+
+int main()
+{
+	gettext("test");
+	return 0;
+}