fdo#74825: fix missing lcms2/libxslt/curl in installation sets

The assumption that all configure variables had been normalized to
TRUE/<empty> turned out not to hold; convert a bit more in that
direction.

(regression from 4af38b099c741c3676aefeb20c515913aaeed666)

Change-Id: I2127c515e8a833a07c9b26ed9d693ce5a1853fe4

15 files changed, 68 insertions, 71 deletions

diff --git a/RepositoryExternal.mk b/RepositoryExternal.mk
index d0cb1fb3fad5..0e7794bb14f3 100644
--- a/RepositoryExternal.mk
+++ b/RepositoryExternal.mk
@@ -109,11 +109,11 @@ endef
 
 endif
 
-ifeq ($(SYSTEM_MDDS),YES)
+ifneq ($(SYSTEM_MDDS),)
 
 gb_LinkTarget__use_mdds_headers :=
 
-else
+else # !SYSTEM_MDDS
 
 define gb_LinkTarget__use_mdds_headers
 $(call gb_LinkTarget_use_unpacked,$(1),mdds)
@@ -124,7 +124,7 @@ $(call gb_LinkTarget_set_include,$(1),\
 
 endef
 
-endif
+endif # SYSTEM_MDDS
 
 ifeq ($(SYSTEM_GLM),YES)
 
@@ -177,7 +177,7 @@ endif # SYSTEM_BLUEZ
 
 # External libraries
 
-ifeq ($(SYSTEM_CPPUNIT),YES)
+ifneq ($(SYSTEM_CPPUNIT),)
 
 define gb_LinkTarget__use_cppunit
 $(call gb_LinkTarget_set_include,$(1),\
@@ -191,7 +191,7 @@ $(call gb_LinkTarget_add_libs,$(1),\
 
 endef
 
-else
+else # !SYSTEM_CPPUNIT
 
 define gb_LinkTarget__use_cppunit
 $(call gb_LinkTarget_use_external_project,$(1),cppunit)
@@ -213,9 +213,9 @@ endif
 
 endef
 
-endif
+endif # SYSTEM_CPPUNIT
 
-ifeq ($(SYSTEM_GLEW),YES)
+ifneq ($(SYSTEM_GLEW),)
 
 define gb_LinkTarget__use_glew
 $(call gb_LinkTarget_set_include,$(1),\
@@ -226,7 +226,7 @@ $(call gb_LinkTarget_add_libs,$(1),$(GLEW_LIBS))
 
 endef
 
-else
+else # !SYSTEM_GLEW
 
 define gb_LinkTarget__use_glew
 $(call gb_LinkTarget_use_external_project,$(1),glew)
@@ -247,7 +247,7 @@ endif
 
 endef
 
-endif
+endif # SYSTEM_GLEW
 
 define gb_LinkTarget__use_iconv
 $(call gb_LinkTarget_add_libs,$(1),-liconv)
@@ -686,7 +686,7 @@ endef
 endif # SYSTEM_BOOST
 
 
-ifeq ($(SYSTEM_CMIS),YES)
+ifneq ($(SYSTEM_CMIS),)
 
 define gb_LinkTarget__use_cmis
 $(call gb_LinkTarget_set_include,$(1),\
@@ -766,7 +766,7 @@ endef
 endif # SYSTEM_LIBATOMIC_OPS
 
 
-ifeq ($(SYSTEM_LIBEXTTEXTCAT),YES)
+ifneq ($(SYSTEM_LIBEXTTEXTCAT),)
 
 define gb_LinkTarget__use_libexttextcat
 $(call gb_LinkTarget_set_include,$(1),\
@@ -848,7 +848,7 @@ endef
 endif # SYSTEM_LIBXML
 
 
-ifeq ($(SYSTEM_LIBXSLT),YES)
+ifneq ($(SYSTEM_LIBXSLT),)
 
 define gb_LinkTarget__use_libxslt
 $(call gb_LinkTarget_set_include,$(1),\
@@ -951,7 +951,7 @@ gb_LinkTarget__use_liblangtag :=
 endif # ENABLE_LIBLANGTAG
 
 
-ifeq ($(SYSTEM_NEON),YES)
+ifneq ($(SYSTEM_NEON),)
 
 define gb_LinkTarget__use_neon
 $(call gb_LinkTarget_add_defs,$(1),\
@@ -988,7 +988,7 @@ endef
 endif # SYSTEM_NEON
 
 
-ifeq ($(SYSTEM_REDLAND),YES)
+ifneq ($(SYSTEM_REDLAND),)
 
 define gb_LinkTarget__use_librdf
 $(call gb_LinkTarget_add_defs,$(1),\
@@ -1173,7 +1173,7 @@ endef
 
 endif # SYSTEM_FONTCONFIG
 
-ifeq ($(SYSTEM_GRAPHITE),YES)
+ifneq ($(SYSTEM_GRAPHITE),)
 
 define gb_LinkTarget__use_graphite
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1184,7 +1184,7 @@ $(call gb_LinkTarget_add_libs,$(1),$(GRAPHITE_LIBS))
 
 endef
 
-else ifeq ($(SYSTEM_GRAPHITE),NO)
+else # !SYSTEM_GRAPHITE
 
 define gb_LinkTarget__use_graphite
 $(call gb_LinkTarget_use_unpacked,$(1),graphite)
@@ -1198,10 +1198,6 @@ $(call gb_LinkTarget_use_static_libraries,$(1),\
 
 endef
 
-else # DISABLED GRAPHITE
-
-gb_LinkTarget__use_graphite :=
-
 endif # SYSTEM_GRAPHITE
 
 ifeq ($(SYSTEM_ICU),YES)
@@ -1295,7 +1291,7 @@ endef
 endif # SYSTEM_ICU
 
 ifeq ($(ENABLE_HARFBUZZ),TRUE)
-ifeq ($(SYSTEM_HARFBUZZ),YES)
+ifneq ($(SYSTEM_HARFBUZZ),)
 
 define gb_LinkTarget__use_harfbuzz
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1306,7 +1302,7 @@ $(call gb_LinkTarget_add_libs,$(1),$(HARFBUZZ_LIBS))
 
 endef
 
-else # SYSTEM_HARFBUZZ != YES
+else # SYSTEM_HARFBUZZ != TRUE
 
 define gb_LinkTarget__use_harfbuzz
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1333,7 +1329,7 @@ gb_LinkTarget__use_openssl:=
 
 else # !DISABLE_OPENSSL
 
-ifeq ($(SYSTEM_OPENSSL),YES)
+ifneq ($(SYSTEM_OPENSSL),)
 
 gb_LinkTarget__use_openssl_headers:=
 gb_ExternalProject__use_openssl:=
@@ -1423,7 +1419,7 @@ gb_LinkTarget__use_libgcrypt:=
 endif # DISABLE_OPENSSL
 
 
-ifeq ($(SYSTEM_CDR),YES)
+ifneq ($(SYSTEM_CDR),)
 
 define gb_LinkTarget__use_cdr
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1450,7 +1446,7 @@ endef
 endif # SYSTEM_CDR
 
 
-ifeq ($(SYSTEM_EBOOK),YES)
+ifneq ($(SYSTEM_EBOOK),)
 
 define gb_LinkTarget__use_ebook
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1485,7 +1481,7 @@ endef
 endif # SYSTEM_EBOOK
 
 
-ifeq ($(SYSTEM_ETONYEK),YES)
+ifneq ($(SYSTEM_ETONYEK),)
 
 define gb_LinkTarget__use_etonyek
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1520,7 +1516,7 @@ endef
 endif # SYSTEM_ETONYEK
 
 
-ifeq ($(SYSTEM_FREEHAND),YES)
+ifneq ($(SYSTEM_FREEHAND),)
 
 define gb_LinkTarget__use_freehand
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1555,7 +1551,7 @@ endef
 endif # SYSTEM_FREEHAND
 
 
-ifeq ($(SYSTEM_ODFGEN),YES)
+ifneq ($(SYSTEM_ODFGEN),)
 
 define gb_LinkTarget__use_odfgen
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1583,7 +1579,7 @@ endef
 endif # SYSTEM_ODFGEN
 
 
-ifeq ($(SYSTEM_ABW),YES)
+ifneq ($(SYSTEM_ABW),)
 
 define gb_LinkTarget__use_abw
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1616,7 +1612,7 @@ endef
 endif # SYSTEM_ABW
 
 
-ifeq ($(SYSTEM_MSPUB),YES)
+ifneq ($(SYSTEM_MSPUB),)
 
 define gb_LinkTarget__use_mspub
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1644,7 +1640,7 @@ endef
 endif # SYSTEM_MSPUB
 
 
-ifeq ($(SYSTEM_VISIO),YES)
+ifneq ($(SYSTEM_VISIO),)
 
 define gb_LinkTarget__use_visio
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1672,7 +1668,7 @@ endef
 endif # SYSTEM_VISIO
 
 
-ifeq ($(SYSTEM_WPD),YES)
+ifneq ($(SYSTEM_WPD),)
 
 define gb_LinkTarget__use_wpd
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1705,7 +1701,7 @@ endef
 endif # SYSTEM_WPD
 
 
-ifeq ($(SYSTEM_WPG),YES)
+ifneq ($(SYSTEM_WPG),)
 
 define gb_LinkTarget__use_wpg
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1738,7 +1734,7 @@ endef
 endif # SYSTEM_WPG
 
 
-ifeq ($(SYSTEM_WPS),YES)
+ifneq ($(SYSTEM_WPS),)
 
 define gb_LinkTarget__use_wps
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1771,7 +1767,7 @@ endef
 endif # SYSTEM_WPS
 
 
-ifeq ($(SYSTEM_MWAW),YES)
+ifneq ($(SYSTEM_MWAW),)
 
 define gb_LinkTarget__use_mwaw
 $(call gb_LinkTarget_set_include,$(1),\
@@ -1799,7 +1795,7 @@ endef
 endif # SYSTEM_MWAW
 
 
-ifeq ($(SYSTEM_LCMS2),YES)
+ifneq ($(SYSTEM_LCMS2),)
 
 define gb_LinkTarget__use_lcms2
 $(call gb_LinkTarget_set_include,$(1),\
@@ -2053,7 +2049,7 @@ define gb_LinkTarget__use_pixbuf
 $(error gb_LinkTarget__use_pixbuf should not be used any more)
 endef
 
-ifeq ($(SYSTEM_LIBPNG),YES)
+ifneq ($(SYSTEM_LIBPNG),)
 
 define gb_LinkTarget__use_png
 $(call gb_LinkTarget_set_include,$(1),\
@@ -2084,7 +2080,7 @@ endef
 endif # !SYSTEM_LIBPNG
 
 
-ifeq ($(SYSTEM_CURL),YES)
+ifneq ($(SYSTEM_CURL),)
 
 define gb_LinkTarget__use_curl
 $(call gb_LinkTarget_set_include,$(1),\
@@ -2352,7 +2348,7 @@ endef
 endif # SYSTEM_FIREBIRD
 
 else # !ENABLE_FIREBIRD_SDBC
-
+n
 gb_LinkTarget__use_firebird :=
 # gb_LinkTarget__use_atomic_ops :=
 # gb_LinkTarget__use_tommath :=
@@ -2670,7 +2666,7 @@ endif # SYSTEM_PYTHON
 # ORCUS
 ifeq ($(ENABLE_ORCUS),TRUE)
 
-ifeq ($(SYSTEM_LIBORCUS),YES)
+ifneq ($(SYSTEM_LIBORCUS),)
 
 define gb_LinkTarget__use_orcus
 $(call gb_LinkTarget_set_include,$(1),\
@@ -2726,7 +2722,7 @@ endif
 
 ifeq ($(ENABLE_EOT),TRUE)
 
-ifeq ($(SYSTEM_LIBEOT),YES)
+ifneq ($(SYSTEM_LIBEOT),)
 
 define gb_LinkTarget__use_libeot
 $(call gb_LinkTarget_set_include,$(1),\
@@ -2816,7 +2812,7 @@ gb_LinkTarget__use_nss3:=
 
 else
 
-ifeq ($(SYSTEM_NSS),YES)
+ifneq ($(SYSTEM_NSS),)
 
 define gb_LinkTarget__use_nss3
 $(call gb_LinkTarget_add_defs,$(1),\
@@ -2844,7 +2840,7 @@ $(call gb_LinkTarget__use_nss3,$(1))
 
 endef
 
-else
+else # !SYSTEM_NSS
 
 define gb_LinkTarget__use_nss3
 $(call gb_LinkTarget_use_package,$(1),nss)
@@ -2904,7 +2900,8 @@ $(call gb_ExternalProject_use_package,$(1),nss)
 
 endef
 
-endif
+endif # SYSTEM_NSS
+
 endif # DESKTOP
 
 ### Jars ############################################################
@@ -3278,7 +3275,7 @@ endef
 
 endif # SYSTEM_LIBXML_FOR_BUILD
 
-ifeq ($(SYSTEM_LIBXSLT_FOR_BUILD),YES)
+ifneq ($(SYSTEM_LIBXSLT_FOR_BUILD),)
 
 gb_ExternalExecutable__register_xsltproc :=
 
diff --git a/configure.ac b/configure.ac
index a09e177831cf..18def26b0916 100644
--- a/configure.ac
+++ b/configure.ac
@@ -7846,7 +7846,7 @@ dnl ===================================================================
 if test "$with_system_lcms2" = "yes"; then
     libo_MINGW_CHECK_DLL([liblcms2])
 else
-    SYSTEM_LCMS2=NO
+    SYSTEM_LCMS2=
 fi
 libo_CHECK_SYSTEM_MODULE([lcms2],[LCMS2],[lcms2],["-I${WORKDIR}/UnpackedTarball/lcms2/include"],["-L${WORKDIR}/UnpackedTarball/lcms2/src/.libs -llcms2"])
 if test "$GCC" = "yes"; then
@@ -7924,7 +7924,7 @@ fi
 AC_MSG_CHECKING([which libxslt to use])
 if test "$with_system_libxml" = "yes"; then
     AC_MSG_RESULT([external])
-    SYSTEM_LIBXSLT=YES
+    SYSTEM_LIBXSLT=TRUE
     if test "$_os" = "Darwin"; then
         dnl make sure to use SDK path
         LIBXSLT_CFLAGS="-I$MACOSX_SDK_PATH/usr/include/libxml2"
@@ -7950,7 +7950,7 @@ if test "$with_system_libxml" = "yes"; then
     libo_MINGW_TRY_DLL([iconv])
 else
     AC_MSG_RESULT([internal])
-    SYSTEM_LIBXSLT=NO
+    SYSTEM_LIBXSLT=
     LIBXSLT_MAJOR=1
     BUILD_TYPE="$BUILD_TYPE LIBXSLT"
 
@@ -8676,7 +8676,7 @@ fi
 
 if test "$with_system_curl" = "yes"; then
     AC_MSG_RESULT([external])
-    SYSTEM_CURL=YES
+    SYSTEM_CURL=TRUE
 
     AC_MSG_CHECKING([whether libcurl is >= 7.19.4])
 
@@ -8723,7 +8723,7 @@ elif test $_os = iOS; then
     ENABLE_CURL=
 else
     AC_MSG_RESULT([internal])
-    SYSTEM_CURL=NO
+    SYSTEM_CURL=
     BUILD_TYPE="$BUILD_TYPE CURL"
     ENABLE_CURL=TRUE
 fi
@@ -8783,7 +8783,7 @@ dnl ===================================================================
 dnl Determine which hash container mdds shall use
 dnl ===================================================================
 AC_MSG_CHECKING([which hash container mdds shall use])
-if test "x$HAVE_CXX11" = "xTRUE" -a "x$SYSTEM_MDDS" = "xYES"; then
+if test "x$HAVE_CXX11" = "xTRUE" -a "x$SYSTEM_MDDS" = "xTRUE"; then
     MDDS_CPPFLAGS=$CXXFLAGS_CXX11
     AC_MSG_RESULT([std::unordered_map])
 else
@@ -9413,7 +9413,7 @@ if test "$enable_openssl" = "yes"; then
     elif test "$_os" = "NetBSD" -o "$_os" = "OpenBSD" -o "$_os" = "DragonFly" \
             && test "$with_system_openssl" != "no"; then
         with_system_openssl=yes
-        SYSTEM_OPENSSL=YES
+        SYSTEM_OPENSSL=TRUE
         OPENSSL_CFLAGS=
         OPENSSL_LIBS="-lssl -lcrypto"
     else
diff --git a/external/curl/ExternalProject_curl.mk b/external/curl/ExternalProject_curl.mk
index 23161a0fea04..e67fdf230e4b 100644
--- a/external/curl/ExternalProject_curl.mk
+++ b/external/curl/ExternalProject_curl.mk
@@ -31,7 +31,7 @@ endif
 endif
 
 # there are 2 include paths, the other one is passed to --with-nss below
-ifeq ($(SYSTEM_NSS),NO)
+ifeq ($(SYSTEM_NSS),)
 curl_CPPFLAGS += -I$(call gb_UnpackedTarball_get_dir,nss)/dist/public/nss
 endif
 
@@ -43,7 +43,7 @@ $(call gb_ExternalProject_get_state_target,curl,build):
 		./configure \
 			$(if $(filter MACOSX IOS,$(OS)),\
 				--with-darwinssl, \
-				--with-nss$(if $(filter NO,$(SYSTEM_NSS)),="$(call gb_UnpackedTarball_get_dir,nss)/dist/out")) \
+				--with-nss$(if $(SYSTEM_NSS),,="$(call gb_UnpackedTarball_get_dir,nss)/dist/out")) \
 			--without-ssl \
 			--without-libidn --enable-ftp --enable-ipv6 --enable-http --disable-gopher \
 			--disable-file --disable-ldap --disable-telnet --disable-dict --without-libssh2 \
diff --git a/external/libpng/Module_libpng.mk b/external/libpng/Module_libpng.mk
index d61375d18d05..31610d3db2fb 100644
--- a/external/libpng/Module_libpng.mk
+++ b/external/libpng/Module_libpng.mk
@@ -9,7 +9,7 @@
 
 $(eval $(call gb_Module_Module,libpng))
 
-ifeq ($(SYSTEM_LIBPNG),NO)
+ifeq ($(SYSTEM_LIBPNG),)
 
 $(eval $(call gb_Module_add_targets,libpng,\
 	StaticLibrary_png \
diff --git a/external/libxmlsec/ExternalProject_xmlsec.mk b/external/libxmlsec/ExternalProject_xmlsec.mk
index 2c4b18ab51ab..851a2680539c 100644
--- a/external/libxmlsec/ExternalProject_xmlsec.mk
+++ b/external/libxmlsec/ExternalProject_xmlsec.mk
@@ -27,7 +27,7 @@ $(call gb_ExternalProject_get_state_target,xmlsec,build) :
 		autoreconf \
 		&& ./configure --build=$(BUILD_PLATFORM) --host=$(HOST_PLATFORM) \
 			--without-libxslt --without-openssl --without-gnutls --disable-crypto-dl \
-			$(if $(filter NO,$(SYSTEM_NSS)),--disable-pkgconfig) \
+			$(if $(SYSTEM_NSS),,--disable-pkgconfig) \
 			CC="$(CC) -mthreads $(if $(filter YES,$(MINGW_SHARED_GCCLIB)),-shared-libgcc)" \
 			LDFLAGS="-Wl$(COMMA)--no-undefined $(ILIB:;= -L)" \
 			LIBS="$(if $(filter YES,$(MINGW_SHARED_GXXLIB)),$(MINGW_SHARED__LIBSTDCPP))" \
@@ -57,7 +57,7 @@ $(call gb_ExternalProject_get_state_target,xmlsec,build) :
 			--with-pic --disable-shared --disable-crypto-dl --without-libxslt --without-gnutls \
 			$(if $(or $(filter-out ANDROID,$(OS)),$(DISABLE_OPENSSL)),--without-openssl,--with-openssl=$(call gb_UnpackedTarball_get_dir,openssl)) \
 			$(if $(filter MACOSX,$(OS)),--prefix=/@.__________________________________________________OOO) \
-			$(if $(filter NO,$(SYSTEM_NSS))$(filter MACOSX,$(OS)),--disable-pkgconfig) \
+			$(if $(SYSTEM_NSS),,$(if $(filter MACOSX,$(OS)),--disable-pkgconfig)) \
 			$(if $(filter YES,$(CROSS_COMPILING)),--build=$(BUILD_PLATFORM) --host=$(HOST_PLATFORM)) \
 			$(if $(filter NO,$(SYSTEM_LIBXML)),LIBXML_CFLAGS="-I$(call gb_UnpackedTarball_get_dir,xml2)/include" LIBXML_LIBS="-L$(call gb_UnpackedTarball_get_dir,xml2)/.libs -lxml2")\
 			$(if $(SYSBASE),CFLAGS="-I$(SYSBASE)/usr/include" \
diff --git a/external/nss/Module_nss.mk b/external/nss/Module_nss.mk
index c1619ffb14d3..5bc94e566d62 100644
--- a/external/nss/Module_nss.mk
+++ b/external/nss/Module_nss.mk
@@ -9,7 +9,7 @@
 
 $(eval $(call gb_Module_Module,nss))
 
-ifeq ($(SYSTEM_NSS),NO)
+ifeq ($(SYSTEM_NSS),)
 ifeq ($(filter ANDROID IOS,$(OS)),)
 $(eval $(call gb_Module_add_targets,nss,\
 	UnpackedTarball_nss \
diff --git a/external/openldap/ExternalProject_openldap.mk b/external/openldap/ExternalProject_openldap.mk
index 10de51fbfe42..022dc0ac149f 100644
--- a/external/openldap/ExternalProject_openldap.mk
+++ b/external/openldap/ExternalProject_openldap.mk
@@ -29,7 +29,7 @@ $(call gb_ExternalProject_get_state_target,openldap,build) :
 				--with-yielding_select=yes \
 				ac_cv_func_memcmp_working=yes \
 			) \
-			$(if $(filter YES,$(SYSTEM_NSS)), \
+			$(if $(SYSTEM_NSS), \
 				CPPFLAGS="$(NSS_CFLAGS)" CFLAGS="$(NSS_CFLAGS)" LDFLAGS="$(NSS_LIBS)" \
 				, \
 				CPPFLAGS="-I$(call gb_UnpackedTarball_get_dir,nss)/dist/public/nss -I$(call gb_UnpackedTarball_get_dir,nss)/dist/out/include" \
diff --git a/external/openssl/Module_openssl.mk b/external/openssl/Module_openssl.mk
index 698aa071021f..002b7083af0f 100644
--- a/external/openssl/Module_openssl.mk
+++ b/external/openssl/Module_openssl.mk
@@ -9,7 +9,7 @@
 
 $(eval $(call gb_Module_Module,openssl))
 
-ifeq ($(SYSTEM_OPENSSL),NO)
+ifeq ($(SYSTEM_OPENSSL),)
 $(eval $(call gb_Module_add_targets,openssl,\
 	UnpackedTarball_openssl \
 	ExternalPackage_openssl \
diff --git a/external/postgresql/ExternalProject_postgresql.mk b/external/postgresql/ExternalProject_postgresql.mk
index 3afa7b80ff28..cd9d8a2ede6a 100644
--- a/external/postgresql/ExternalProject_postgresql.mk
+++ b/external/postgresql/ExternalProject_postgresql.mk
@@ -32,7 +32,7 @@ postgresql_CPPFLAGS := $(ZLIB_CFLAGS)
 postgresql_LDFLAGS  :=
 
 ifeq ($(DISABLE_OPENSSL),)
-ifeq ($(SYSTEM_OPENSSL),NO)
+ifeq ($(SYSTEM_OPENSSL),)
 postgresql_CPPFLAGS += -I$(call gb_UnpackedTarball_get_dir,openssl)/include
 postgresql_LDFLAGS  += -L$(call gb_UnpackedTarball_get_dir,openssl)/
 endif
@@ -44,7 +44,7 @@ postgresql_LDFLAGS  += \
 	-L$(call gb_UnpackedTarball_get_dir,openldap)/libraries/libldap_r/.libs \
 	-L$(call gb_UnpackedTarball_get_dir,openldap)/libraries/libldap/.libs \
 	-L$(call gb_UnpackedTarball_get_dir,openldap)/libraries/liblber/.libs \
-	$(if $(filter NO,$(SYSTEM_NSS)),\
+	$(if $(SYSTEM_NSS),,\
 		-L$(call gb_UnpackedTarball_get_dir,nss)/dist/out/lib) \
 
 endif
diff --git a/external/python3/ExternalProject_python3.mk b/external/python3/ExternalProject_python3.mk
index 70063f0f52eb..9d620b749b6d 100644
--- a/external/python3/ExternalProject_python3.mk
+++ b/external/python3/ExternalProject_python3.mk
@@ -73,14 +73,14 @@ $(call gb_ExternalProject_get_state_target,python3,build) :
 			--enable-shared \
 		) \
 		CC="$(strip $(CC) \
-			$(if $(filter NO,$(SYSTEM_OPENSSL)),-I$(call gb_UnpackedTarball_get_dir,openssl)/include \
+			$(if $(SYSTEM_OPENSSL),,-I$(call gb_UnpackedTarball_get_dir,openssl)/include \
 				$(if $(DISABLE_OPENSSL),,-I$(call gb_UnpackedTarball_get_dir,openssl)/include)) \
 			$(if $(filter NO,$(SYSTEM_EXPAT)),-I$(call gb_UnpackedTarball_get_dir,expat)/lib) \
 			$(if $(SYSBASE), -I$(SYSBASE)/usr/include) \
 			)" \
 		$(if $(python3_cflags),CFLAGS='$(python3_cflags)') \
 		LDFLAGS="$(strip $(LDFLAGS) \
-			$(if $(filter YES,$(SYSTEM_OPENSSL)),, -L$(call gb_UnpackedTarball_get_dir,openssl)) \
+			$(if $(SYSTEM_OPENSSL),,-L$(call gb_UnpackedTarball_get_dir,openssl)) \
 			$(if $(filter YES,$(SYSTEM_EXPAT)),, -L$(gb_StaticLibrary_WORKDIR)) \
 			$(if $(SYSBASE), -L$(SYSBASE)/usr/lib) \
 			$(if $(filter WNT-GCC,$(OS)-$(COM)), -shared-libgcc \
diff --git a/external/redland/Module_redland.mk b/external/redland/Module_redland.mk
index 431a66da5323..645e4193d827 100644
--- a/external/redland/Module_redland.mk
+++ b/external/redland/Module_redland.mk
@@ -9,7 +9,7 @@
 
 $(eval $(call gb_Module_Module,redland))
 
-ifeq ($(SYSTEM_REDLAND),NO)
+ifeq ($(SYSTEM_REDLAND),)
 $(eval $(call gb_Module_add_targets,redland,\
 	UnpackedTarball_raptor \
 	UnpackedTarball_rasqal \
diff --git a/m4/libo_externals.m4 b/m4/libo_externals.m4
index c17292d93f49..3fe9fce18648 100644
--- a/m4/libo_externals.m4
+++ b/m4/libo_externals.m4
@@ -14,12 +14,12 @@ AC_ARG_WITH(system-$1,
 AC_MSG_CHECKING([which $1 to use])
 if test "$with_system_$1" = "yes"; then
     AC_MSG_RESULT([external])
-    SYSTEM_$2=YES
+    SYSTEM_$2=TRUE
     PKG_CHECK_MODULES([$2], [$3])
     $2_CFLAGS=$(printf '%s' "${$2_CFLAGS}" | sed -e "s/-I/${ISYSTEM?}/g")
 else
     AC_MSG_RESULT([internal])
-    SYSTEM_$2=NO
+    SYSTEM_$2=
     $2_CFLAGS=$4
     $2_LIBS=$5
     BUILD_TYPE="$BUILD_TYPE $2"
diff --git a/sc/Library_sc.mk b/sc/Library_sc.mk
index 32d71da259ce..2b2ef76567a8 100644
--- a/sc/Library_sc.mk
+++ b/sc/Library_sc.mk
@@ -45,7 +45,7 @@ $(eval $(call gb_Library_use_externals,sc,\
     mdds_headers \
 ))
 
-ifeq ($(SYSTEM_LIBORCUS),YES)
+ifneq ($(SYSTEM_LIBORCUS),)
 $(eval $(call gb_Library_use_externals,sc,orcus))
 else
 $(eval $(call gb_Library_use_externals,sc,orcus-parser))
diff --git a/sc/Library_scqahelper.mk b/sc/Library_scqahelper.mk
index cbdc99df6441..351b1150f0ea 100644
--- a/sc/Library_scqahelper.mk
+++ b/sc/Library_scqahelper.mk
@@ -21,7 +21,7 @@ $(eval $(call gb_Library_use_externals,scqahelper, \
 	cppunit \
 ))
 
-ifeq ($(SYSTEM_LIBORCUS),YES)
+ifneq ($(SYSTEM_LIBORCUS),)
 $(eval $(call gb_Library_use_externals,scqahelper,orcus))
 else
 $(eval $(call gb_Library_use_externals,scqahelper,orcus-parser))
diff --git a/scp2/InstallModule_ooo.mk b/scp2/InstallModule_ooo.mk
index 4d4e33d0557b..7f53d5fd2495 100644
--- a/scp2/InstallModule_ooo.mk
+++ b/scp2/InstallModule_ooo.mk
@@ -119,13 +119,13 @@ $(eval $(call gb_InstallModule_add_defs,scp2/ooo,\
 	-DICU_MAJOR=$(ICU_MAJOR) \
 ))
 
-ifneq ($(SYSTEM_LIBXSLT),YES)
+ifeq ($(SYSTEM_LIBXSLT),)
 $(eval $(call gb_InstallModule_add_defs,scp2/ooo,\
 	-DLIBXSLT_MAJOR=$(LIBXSLT_MAJOR) \
 ))
 endif
 
-ifneq ($(SYSTEM_REDLAND),YES)
+ifeq ($(SYSTEM_REDLAND),)
 
 $(eval $(call gb_InstallModule_add_defs,scp2/ooo,\
 	-DRAPTOR_MAJOR=$(RAPTOR_MAJOR) \