replace target with OBJ on nfs, fix root creation of files

[Roy Marples <roy%marples.name@localhost>]

Hi

My pkgsrc obj directory is on NFS with root access disabled.
Whilst installing has been fine, pkg_rolling-replace fails at the first 
hurdle because the replace target wants to create files in WRKDIR to 
store old and new package names. This fails because the files are 
created AFTER the super user command.

There is a note in the mk source to say that all of the replace must 
happen within a "transaction." I don't feel that name resolution should 
be part of this becase the same files are used by the undo target, which 
by nature cannot be part of this transaction.

Attached is a patch (relative to pkgsrc/mk) that allow 
pkg_rolling-replace to work with my setup by moving the creation of 
these files to before the super user command.

Is this a safe thing to do? I'm not familiar with this area of pkgsrc, 
hence this email.

Roy

Index: install/replace.mk
===================================================================
RCS file: /cvsroot/pkgsrc/mk/install/replace.mk,v
retrieving revision 1.18
diff -u -p -r1.18 replace.mk
--- install/replace.mk	10 Apr 2016 15:58:02 -0000	1.18
+++ install/replace.mk	19 Jan 2019 23:41:16 -0000
@@ -29,6 +29,7 @@ _REPLACE_TARGETS+=	package
 .endif
 _REPLACE_TARGETS+=	replace-message
 _REPLACE_TARGETS+=	unprivileged-install-hook
+_REPLACE_TARGETS+=	replace-names
 
 #
 # replace
Index: pkgformat/pkg/replace.mk
===================================================================
RCS file: /cvsroot/pkgsrc/mk/pkgformat/pkg/replace.mk,v
retrieving revision 1.5
diff -u -p -r1.5 replace.mk
--- pkgformat/pkg/replace.mk	19 Aug 2017 00:30:19 -0000	1.5
+++ pkgformat/pkg/replace.mk	19 Jan 2019 23:41:16 -0000
@@ -11,7 +11,6 @@
 # to installing the new package, should be one transaction.
 #
 _pkgformat-replace: \
-	replace-names \
 	replace-tarup \
 	replace-preserve-installed-info \
 	replace-preserve-required-by \
@@ -24,7 +23,6 @@ _pkgformat-replace: \
 
 # tarup is omitted for DESTDIR, because the benefits are very small
 _pkgformat-destdir-replace: \
-	replace-names \
 	replace-destdir \
 	.PHONY