CMake: `zip` is required for the build

Print error message if `zip` is not found. It is used for creating
fontpacks.

1 files changed, 5 insertions, 2 deletions

diff --git a/res/Fontpack.cmake b/res/Fontpack.cmake
index 9471c93d..26d6df1e 100644
--- a/res/Fontpack.cmake
+++ b/res/Fontpack.cmake
@@ -1,15 +1,18 @@
 find_program (ZIP_EXECUTABLE zip DOC "ZIP archiver")
+if (NOT ZIP_EXECUTABLE)
+    message (FATAL_ERROR "Please install 'zip' to create fontpacks.")
+endif ()
 
 function (make_fontpack src)
     get_filename_component (dst ${src} NAME)
     set (fn ${CMAKE_BINARY_DIR}/${dst})
     execute_process (COMMAND ${CMAKE_COMMAND} -E remove ${fn})
     file (GLOB files RELATIVE ${CMAKE_SOURCE_DIR}/${src}
-        ${CMAKE_SOURCE_DIR}/${src}/*        
+        ${CMAKE_SOURCE_DIR}/${src}/*
     )
     message (STATUS "  ${src}")
     execute_process (
-        COMMAND ${ZIP_EXECUTABLE} -0 ${fn} ${files}        
+        COMMAND ${ZIP_EXECUTABLE} -0 ${fn} ${files}
         WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}/${src}
         OUTPUT_QUIET
     )