deliver sane header only when it's being used

Change-Id: I38a3dfb14375bb4abee7beaa3127c3a4cce1b9a2

Module_tail_build.mk

@@ -85,9 +85,7 @@ $(eval $(call gb_Module_add_moduledirs,tail_end,\
     reportbuilder \
     reportdesign \
     rsc \
-	$(if $(filter SANE,$(BUILD_TYPE)),\
-		sane \
-	) \
+    sane \
 	sax \
     sc \
     scaddins \

config_host.mk.in

@@ -526,7 +526,6 @@ export SYSTEM_PYTHON=@SYSTEM_PYTHON@
 export SYSTEM_REDLAND=@SYSTEM_REDLAND@
 export SYSTEM_RHINO=@SYSTEM_RHINO@
 export SYSTEM_SAMPLEICC=@SYSTEM_SAMPLEICC@
-export SYSTEM_SANE_HEADER=@SYSTEM_SANE_HEADER@
 export SYSTEM_SAXON=@SYSTEM_SAXON@
 export SYSTEM_SERVLETAPI=@SYSTEM_SERVLETAPI@
 export SYSTEM_STDLIBS=@SYSTEM_STDLIBS@

configure.in

@@ -7799,15 +7799,12 @@ dnl ===================================================================
 AC_MSG_CHECKING([which sane header to use])
 if test "$with_system_sane" = "yes"; then
     AC_MSG_RESULT([external])
-    SYSTEM_SANE_HEADER=YES
     AC_CHECK_HEADER(sane/sane.h, [],
       [AC_MSG_ERROR(sane not found. install sane)], [])
 else
     AC_MSG_RESULT([internal])
-    SYSTEM_SANE_HEADER=NO
     BUILD_TYPE="$BUILD_TYPE SANE"
 fi
-AC_SUBST(SYSTEM_SANE_HEADER)
 
 dnl ===================================================================
 dnl Check for system icu

extensions/Library_scn.mk

@@ -30,10 +30,6 @@ $(eval $(call gb_Library_Library,scn))
 
 $(eval $(call gb_Library_set_componentfile,scn,extensions/source/scanner/scn))
 
-$(eval $(call gb_Library_use_packages,scn,\
-    sane_inc \
-))
-
 $(eval $(call gb_Library_use_api,scn,\
 	udkapi \
 	offapi \
@@ -63,6 +59,10 @@ $(eval $(call gb_Library_add_exception_objects,scn,\
 ))
 else
 ifeq ($(GUI),UNX)
+ifneq (,$(filter SANE,$(BUILD_TYPE)))
+$(eval $(call gb_Library_use_packages,scn,sane_inc))
+endif
+
 $(eval $(call gb_Library_add_exception_objects,scn,\
 	extensions/source/scanner/grid \
 	extensions/source/scanner/sane \

sane/Module_sane.mk

@@ -29,6 +29,10 @@
 
 $(eval $(call gb_Module_Module,sane))
 
+ifeq ($(GUI),UNX)
+ifneq (,$(filter SANE,$(BUILD_TYPE)))
 $(eval $(call gb_Module_add_targets,sane,\
 	Package_inc \
 ))
+endif
+endif