Fixed building with cmake when fcitx isn't installed
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9038abf..54a23f0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -916,6 +916,8 @@
       endif()
     endif()
 
+    check_include_file("fcitx/frontend.h" HAVE_FCITX_FRONTEND_H)
+
   endif()
 
   if(INPUT_TSLIB)
diff --git a/include/SDL_config.h.cmake b/include/SDL_config.h.cmake
index 57a44b9..98c62a9 100644
--- a/include/SDL_config.h.cmake
+++ b/include/SDL_config.h.cmake
@@ -82,6 +82,7 @@
 #cmakedefine HAVE_LIBUDEV_H 1
 #cmakedefine HAVE_DBUS_DBUS_H 1
 #cmakedefine HAVE_IBUS_IBUS_H 1
+#cmakedefine HAVE_FCITX_FRONTEND_H 1
 
 /* C library functions */
 #cmakedefine HAVE_MALLOC 1
diff --git a/src/core/linux/SDL_fcitx.c b/src/core/linux/SDL_fcitx.c
index 05361ff..eff8f7f 100644
--- a/src/core/linux/SDL_fcitx.c
+++ b/src/core/linux/SDL_fcitx.c
@@ -18,6 +18,9 @@
      misrepresented as being the original software.
   3. This notice may not be removed or altered from any source distribution.
 */
+#include "SDL_config.h"
+
+#ifdef HAVE_FCITX_FRONTEND_H
 
 #include <fcitx/frontend.h>
 #include <unistd.h>
@@ -545,4 +548,6 @@
     }
 }
 
+#endif /* HAVE_FCITX_FRONTEND_H */
+
 /* vi: set ts=4 sw=4 expandtab: */