Remove useless X11 libraries when building with -DFLTK_BACKEND_X11=0

CMake/options.cmake

@@ -287,7 +287,9 @@ if(UNIX)
 
   if(FLTK_BACKEND_WAYLAND)
     set(FLTK_USE_WAYLAND 1)
-    include(FindX11)
+    if(FLTK_BACKEND_X11)
+      include(FindX11)
+    endif()
     if(FLTK_BACKEND_X11 AND X11_FOUND)
       set(FLTK_USE_X11 1) # build a hybrid Wayland/X11 library
     else()
@@ -299,7 +301,7 @@ if(UNIX)
     set(USE_SYSTEM_LIBDECOR 1)
     unset(FLTK_USE_XRENDER CACHE)
     unset(FLTK_USE_XINERAMA CACHE)
-    # unset(FLTK_USE_XFT CACHE)
+    unset(FLTK_USE_XFT CACHE)
     unset(FLTK_USE_XCURSOR CACHE)
     unset(FLTK_USE_XFIXES CACHE)
     if(X11_FOUND)
@@ -860,11 +862,11 @@ if((X11_Xft_FOUND OR NOT USE_PANGOXFT) AND FLTK_USE_PANGO)
     list(REMOVE_DUPLICATES FLTK_LDLIBS)
 
     # *FIXME* Libraries should not be added explicitly if possible
-    if(FLTK_BACKEND_WAYLAND)
+    if(FLTK_BACKEND_WAYLAND AND FLTK_USE_LIBDECOR_GTK AND NOT USE_SYSTEM_LIBDECOR)
       list(APPEND FLTK_LDLIBS -lgtk-3 -lgdk-3 -lgio-2.0)
-      if(FLTK_BACKEND_X11)
-        list(APPEND FLTK_LDLIBS -lX11)
-      endif()
+    endif()
+    if(FLTK_BACKEND_X11)
+      list(APPEND FLTK_LDLIBS -lX11)
     endif()
 
     list(REMOVE_DUPLICATES FLTK_LDLIBS)

src/CMakeLists.txt

@@ -764,9 +764,6 @@ if(UNIX AND FLTK_BACKEND_WAYLAND)
   if(DBUS_FOUND)
     list(APPEND OPTIONAL_LIBS "${DBUS_LDFLAGS}")
   endif(DBUS_FOUND)
-  if(NOT FLTK_BACKEND_WAYLAND_ONLY)
-    list(APPEND OPTIONAL_LIBS "-lXcursor -lXrender -lXinerama -lXfixes -lXft -lXext -lX11")
-  endif(NOT FLTK_BACKEND_WAYLAND_ONLY)
   if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux" AND NOT FLTK_BUILD_SHARED_LIBS)
     list(APPEND OPTIONAL_LIBS "-no-pie")
   endif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux" AND NOT FLTK_BUILD_SHARED_LIBS)