normalize values of SYSTEM_GLM, SYSTEM_VIGRA

Change-Id: Idc28f8be610aae57477f18c26ffcb97a24a2ab82

RepositoryExternal.mk

@@ -92,7 +92,7 @@ endef
 
 endif
 
-ifeq ($(SYSTEM_VIGRA),YES)
+ifneq ($(SYSTEM_VIGRA),)
 
 gb_LinkTarget__use_vigra_headers :=
 
@@ -126,7 +126,7 @@ endef
 
 endif # SYSTEM_MDDS
 
-ifeq ($(SYSTEM_GLM),YES)
+ifneq ($(SYSTEM_GLM),)
 
 gb_LinkTarget__use_glm_headers :=
 

configure.ac

@@ -8798,7 +8798,7 @@ dnl ===================================================================
 AC_MSG_CHECKING([which glm to use])
 if test "$with_system_glm" = "yes"; then
     AC_MSG_RESULT([external])
-    SYSTEM_GLM=YES
+    SYSTEM_GLM=TRUE
     AC_LANG_PUSH([C++])
     AC_CHECK_HEADER([glm/glm.hpp], [],
        [AC_MSG_ERROR([glm/glm.hpp not found. install glm])], [])
@@ -8806,7 +8806,7 @@ if test "$with_system_glm" = "yes"; then
 else
     AC_MSG_RESULT([internal])
     BUILD_TYPE="$BUILD_TYPE GLM"
-    SYSTEM_GLM=NO
+    SYSTEM_GLM=
 fi
 AC_SUBST([SYSTEM_GLM])
 
@@ -8821,7 +8821,7 @@ dnl ===================================================================
 AC_MSG_CHECKING([which vigra to use])
 if test "$with_system_vigra" = "yes"; then
     AC_MSG_RESULT([external])
-    SYSTEM_VIGRA=YES
+    SYSTEM_VIGRA=TRUE
     AC_LANG_PUSH([C++])
     AC_CHECK_HEADER(vigra/copyimage.hxx, [],
        [AC_MSG_ERROR(vigra/copyimage.hxx not found. install vigra)], [])
@@ -8829,7 +8829,7 @@ if test "$with_system_vigra" = "yes"; then
 else
     AC_MSG_RESULT([internal])
     BUILD_TYPE="$BUILD_TYPE VIGRA"
-    SYSTEM_VIGRA=NO
+    SYSTEM_VIGRA=
 fi
 AC_SUBST(SYSTEM_VIGRA)
 

external/glm/Module_glm.mk

@@ -9,7 +9,7 @@
 
 $(eval $(call gb_Module_Module,glm))
 
-ifeq ($(SYSTEM_GLM),NO)
+ifeq ($(SYSTEM_GLM),)
 
 $(eval $(call gb_Module_add_targets,glm,\
 	UnpackedTarball_glm \

external/vigra/Module_vigra.mk

@@ -9,7 +9,7 @@
 
 $(eval $(call gb_Module_Module,vigra))
 
-ifeq ($(SYSTEM_VIGRA),NO)
+ifeq ($(SYSTEM_VIGRA),)
 
 $(eval $(call gb_Module_add_targets,vigra,\
 	UnpackedTarball_vigra \