build: Added a check for NSIS.

CPackConfig.cmake

@@ -22,16 +22,21 @@ set(CPACK_SOURCE_GENERATOR "TGZ")
 set(CPACK_SOURCE_IGNORE_FILES "~$;[.]swp$;/[.]svn/;/[.]git/;.gitignore;/build/;tags;cscope.*")
 set(CPACK_SOURCE_PACKAGE_FILE_NAME "${CPACK_PACKAGE_NAME}-${CPACK_PACKAGE_VERSION}")
 
+if (WIN32)
+    set(CPACK_GENERATOR "ZIP")
 
-### nsis generator
-set(CPACK_GENERATOR "NSIS")
+    ### nsis generator
+    find_package(NSIS)
+    if (HAVE_NSIS)
+        set(CPACK_GENERATOR "${CPACK_GENERATOR};NSIS")
+        set(CPACK_NSIS_DISPLAY_NAME "The SSH Library")
+        set(CPACK_NSIS_COMPRESSOR "/SOLID zlib")
+        set(CPACK_NSIS_MENU_LINKS "http://www.libssh.org/" "libssh homepage")
+    endif (HAVE_NSIS)
+endif (WIN32)
 
 set(CPACK_PACKAGE_INSTALL_DIRECTORY "libssh")
 
-set(CPACK_NSIS_DISPLAY_NAME "The SSH Library")
-set(CPACK_NSIS_COMPRESSOR "/SOLID zlib")
-set(CPACK_NSIS_MENU_LINKS "http://www.libssh.org/" "libssh homepage")
-
 set(CPACK_PACKAGE_FILE_NAME ${APPLICATION_NAME}-${CPACK_PACKAGE_VERSION})
 
 set(CPACK_COMPONENT_LIBRARIES_DISPLAY_NAME "Libraries")

cmake/Modules/FindNSIS.cmake

@@ -0,0 +1,31 @@
+# - Try to find NSIS
+# Once done this will define
+#
+#  NSIS_FOUND - system has NSIS
+#  NSIS_MAKE - NSIS creator executable
+#
+#  Copyright (c) 2010 Andreas Schneider <mail@cynapses.org>
+#
+#  Redistribution and use is allowed according to the terms of the New
+#  BSD license.
+#  For details see the accompanying COPYING-CMAKE-SCRIPTS file.
+#
+
+if (NSIS_MAKE)
+  # in cache already
+  set(NSIS_FOUND TRUE)
+elseif (NSIS_MAKE)
+    find_program(NSIS_MAKE
+        NAMES
+            makensis
+        PATHS
+            ${_NSIS_DIR}
+            ${_NSIS_DIR}/Bin
+            $ENV{PROGRAMFILES}/NSIS
+    )
+
+    include(FindPackageHandleStandardArgs)
+    find_package_handle_standard_args(NSIS DEFAULT_MSG NSIS_MAKE)
+
+    mark_as_advanced(NSIS_MAKE)
+endif (NSIS_MAKE)