From 00428a515c31b93a4d454b4a1a607803f248688f Mon Sep 17 00:00:00 2001
From: Bryan Drewery <bdrewery@FreeBSD.org>
Date: Sun, 5 Nov 2017 00:12:05 +0000
Subject: [PATCH] Always try to set .OBJDIR, even if AUTO_OBJ is enabled, and
 fallback to .CURDIR.

When AUTO_OBJ is enabled this change becomes redundant with the auto.obj.mk
check added in r325404.  However, it is possible that new code is added
at some point between src.sys.obj.mk and auto.obj.mk that disables AUTO_OBJ.
That could leave make with a bogus and unsafe .OBJDIR in some cases.

Sponsored by:	Dell EMC Isilon
---
 share/mk/src.sys.obj.mk | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/share/mk/src.sys.obj.mk b/share/mk/src.sys.obj.mk
index 41a26deeec4..a46efe5f4d8 100644
--- a/share/mk/src.sys.obj.mk
+++ b/share/mk/src.sys.obj.mk
@@ -154,9 +154,8 @@ MK_AUTO_OBJ:=	${OBJDIR_WRITABLE}
 .export MK_AUTO_OBJ
 .endif	# ${MK_AUTO_OBJ} == "no" && ...
 
-# Assign this directory as .OBJDIR if possible after determining if AUTO_OBJ
-# can be enabled by default.
-.if ${MK_AUTO_OBJ} == "no"
+# Assign this directory as .OBJDIR if possible.
+#
 # The expected OBJDIR already exists, set it as .OBJDIR.
 .if !empty(MAKEOBJDIRPREFIX) && exists(${MAKEOBJDIRPREFIX}${.CURDIR})
 .OBJDIR: ${MAKEOBJDIRPREFIX}${.CURDIR}
@@ -169,5 +168,10 @@ MK_AUTO_OBJ:=	${OBJDIR_WRITABLE}
 .elif ${MAKE_VERSION} <= 20170720 && \
     ${.CURDIR} == ${SRCTOP} && ${.OBJDIR} == ${SRCTOP}/
 .OBJDIR: ${.CURDIR}
+.else
+# The OBJDIR we wanted does not yet exist, ensure we default to safe .CURDIR
+# in case make started with a bogus MAKEOBJDIR, that expanded before OBJTOP
+# was set, that happened to match some unexpected directory.  Either
+# auto.obj.mk or bsd.obj.mk will create the directory and fix .OBJDIR later.
+.OBJDIR: ${.CURDIR}
 .endif
-.endif	# ${MK_AUTO_OBJ} == "no"