Index: stable/12/share/mk/bsd.mkopt.mk
===================================================================
--- stable/12/share/mk/bsd.mkopt.mk	(revision 352781)
+++ stable/12/share/mk/bsd.mkopt.mk	(revision 352782)
@@ -1,86 +1,90 @@
 #
 # $FreeBSD$
 #
 # Generic mechanism to deal with WITH and WITHOUT options and turn
 # them into MK_ options.
 #
 # For each option FOO in __DEFAULT_YES_OPTIONS, MK_FOO is set to
 # "yes", unless WITHOUT_FOO is defined, in which case it is set to
 # "no".
 #
 # For each option FOO in __DEFAULT_NO_OPTIONS, MK_FOO is set to "no",
 # unless WITH_FOO is defined, in which case it is set to "yes".
 #
+# For each entry FOO/BAR in __DEFAULT_DEPENDENT_OPTIONS,
+# MK_FOO is set to "no" if WITHOUT_FOO is defined,
+# "yes" if WITH_FOO is defined, otherwise the value of MK_BAR.
+#
 # If both WITH_FOO and WITHOUT_FOO are defined, WITHOUT_FOO wins and
 # MK_FOO is set to "no" regardless of which list it was in.
 #
-# Both __DEFAULT_YES_OPTIONS and __DEFAULT_NO_OPTIONS are undef'd
-# after all this processing, allowing this file to be included
-# multiple times with different lists.
+# All of __DEFAULT_YES_OPTIONS, __DEFAULT_NO_OPTIONS and
+# __DEFAULT_DEPENDENT_OPTIONS are undef'd after all this processing,
+# allowing this file to be included multiple times with different lists.
 #
 # Other parts of the build system will set BROKEN_OPTIONS to a list
 # of options that are broken on this platform. This will not be unset
 # before returning. Clients are expected to always += this variable.
 #
 # Users should generally define WITH_FOO or WITHOUT_FOO, but the build
 # system should use MK_FOO={yes,no} when it needs to override the
 # user's desires or default behavior.
 #
 
 #
 # MK_* options which default to "yes".
 #
 .for var in ${__DEFAULT_YES_OPTIONS}
 .if !defined(MK_${var})
 .if defined(WITHOUT_${var})			# WITHOUT always wins
 MK_${var}:=	no
 .else
 MK_${var}:=	yes
 .endif
 .else
 .if ${MK_${var}} != "yes" && ${MK_${var}} != "no"
 .error "Illegal value for MK_${var}: ${MK_${var}}"
 .endif
 .endif # !defined(MK_${var})
 .endfor
 .undef __DEFAULT_YES_OPTIONS
 
 #
 # MK_* options which default to "no".
 #
 .for var in ${__DEFAULT_NO_OPTIONS}
 .if !defined(MK_${var})
 .if defined(WITH_${var}) && !defined(WITHOUT_${var}) # WITHOUT always wins
 MK_${var}:=	yes
 .else
 MK_${var}:=	no
 .endif
 .else
 .if ${MK_${var}} != "yes" && ${MK_${var}} != "no"
 .error "Illegal value for MK_${var}: ${MK_${var}}"
 .endif
 .endif # !defined(MK_${var})
 .endfor
 .undef __DEFAULT_NO_OPTIONS
 
 #
 # MK_* options which are always no, usually because they are
 # unsupported/badly broken on this architecture.
 #
 .for var in ${BROKEN_OPTIONS}
 MK_${var}:=	no
 .endfor
 
 .for vv in ${__DEFAULT_DEPENDENT_OPTIONS}
 .if defined(WITH_${vv:H}) && defined(WITHOUT_${vv:H})
 MK_${vv:H}?= no
 .elif defined(WITH_${vv:H})
 MK_${vv:H}?= yes
 .elif defined(WITHOUT_${vv:H})
 MK_${vv:H}?= no
 .else
 MK_${vv:H}?= ${MK_${vv:T}}
 .endif
 MK_${vv:H}:= ${MK_${vv:H}}
 .endfor
 .undef __DEFAULT_DEPENDENT_OPTIONS