--- a/make/Javadoc.gmk	Thu Apr 27 16:07:55 2017 +0000
+++ b/make/Javadoc.gmk	Thu Apr 27 21:16:00 2017 +0000
@@ -35,6 +35,11 @@
 $(eval $(call ReadImportMetaData))
 
 ################################################################################
+
+# Hook to include the corresponding custom file, if present.
+$(eval $(call IncludeCustomExtension, , Javadoc.gmk))
+
+################################################################################
 # Javadoc settings
 
 # On top of the sources that was used to compile the JDK, we need some
@@ -43,7 +48,7 @@
     $(SUPPORT_OUTPUTDIR)/rmic/* $(JDK_TOPDIR)/src/*/share/doc/stub)
 
 # Should we use -Xdocrootparent? Allow custom to overwrite.
-DOCROOTPARENT_FLAG = TRUE
+DOCROOTPARENT_FLAG ?= TRUE
 
 # URLs
 JAVADOC_BASE_URL := http://docs.oracle.com/javase/$(VERSION_SPECIFICATION)/docs
@@ -74,8 +79,10 @@
     -tag see \
     -tag 'jvms:a:See <cite>The Java&trade; Virtual Machine Specification</cite>:' \
     -tag 'jls:a:See <cite>The Java&trade; Language Specification</cite>:' \
+    -taglet build.tools.taglet.ExtLink \
     -taglet build.tools.taglet.Incubating \
     -tagletpath $(BUILDTOOLS_OUTPUTDIR)/jdk_tools_classes \
+    $(CUSTOM_JAVADOC_TAGS) \
     #
 
 # Which doclint checks to ignore
@@ -217,7 +224,7 @@
   $1_OPTIONS += -Xdoclint:all,$$(call CommaList, $$(addprefix -, \
       $$(JAVADOC_DISABLED_DOCLINT)))
 
-  ifneq ($$($$DOCROOTPARENT_FLAG), )
+  ifeq ($$($$DOCROOTPARENT_FLAG), TRUE)
     $1_OPTIONS += -Xdocrootparent $$(JAVADOC_BASE_URL)
   endif
 
@@ -429,11 +436,6 @@
 
 ################################################################################
 
-# Hook to include the corresponding custom file, if present.
-$(eval $(call IncludeCustomExtension, , Javadoc.gmk))
-
-################################################################################
-
 docs-jdk-api-javadoc: $(JDK_API_JAVADOC_TARGETS)
 
 docs-jdk-api-modulegraph: $(JDK_API_MODULEGRAPH_TARGETS)