From d90331f910d8d7df871035860303bb749f611d1c Mon Sep 17 00:00:00 2001
From: Doug Barton <dougb@FreeBSD.org>
Date: Sat, 19 Dec 2009 05:20:26 +0000
Subject: [PATCH] Fix a problem with how mergemaster handles the hard links for
 /.cshrc and /.profile. The problem is that install(1) will unlink the old
 file before it installs the new one, which means that in the best case we
 have to compare the changes for the old file twice.

So, change the logic to first test to see if the link exists, then
install the file. Then if the link was there and we're using -i, just
create the link in /root and be done with it. Otherwise display the
message to the user and give them the option.

Because we are now sorting things before doing the comparison we can
know conclusively that the files in / should be the sources, and the
files in /root will be the targets, so adjust the paths accordingly.

While I'm here, split a too-long error message into two lines and
just return at the end of handling these files instead of setting
the variable that says "do nothing" and then returning at the end
of the function anyway.
---
 usr.sbin/mergemaster/mergemaster.sh | 33 +++++++++++++++++------------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/usr.sbin/mergemaster/mergemaster.sh b/usr.sbin/mergemaster/mergemaster.sh
index fa8874175a93..7a33c4d86566 100755
--- a/usr.sbin/mergemaster/mergemaster.sh
+++ b/usr.sbin/mergemaster/mergemaster.sh
@@ -840,8 +840,19 @@ mm_install () {
       DONT_INSTALL=yes
       ;;
     /.cshrc | /.profile)
-      case "${AUTO_INSTALL}" in
-      '')
+      local st_nlink
+
+      # install will unlink the file before it installs the new one,
+      # so we have to restore/create the link afterwards.
+      #
+      st_nlink=0		# In case the file does not yet exist
+      eval $(stat -s ${DESTDIR}${COMPFILE#.} 2>/dev/null)
+
+      do_install_and_rm "${FILE_MODE}" "${1}" "${DESTDIR}${INSTALL_DIR}"
+
+      if [ -n "${AUTO_INSTALL}" -a $st_nlink -gt 1 ]; then
+        HANDLE_LINK=l
+      else
         case "${LINK_EXPLAINED}" in
         '')
           echo "   *** Historically BSD derived systems have had a"
@@ -855,17 +866,13 @@ mm_install () {
         esac
 
         echo "   Use 'd' to delete the temporary ${COMPFILE}"
-        echo "   Use 'l' to delete the existing ${DESTDIR}${COMPFILE#.} and create the link"
+        echo "   Use 'l' to delete the existing ${DESTDIR}/root/${COMPFILE##*/} and create the link"
         echo ''
         echo "   Default is to leave the temporary file to deal with by hand"
         echo ''
         echo -n "  How should I handle ${COMPFILE}? [Leave it to install later] "
         read HANDLE_LINK
-        ;;
-      *)  # Part of AUTO_INSTALL
-        HANDLE_LINK=l
-        ;;
-      esac
+      fi
 
       case "${HANDLE_LINK}" in
       [dD]*)
@@ -875,19 +882,19 @@ mm_install () {
         ;;
       [lL]*)
         echo ''
-        rm -f "${DESTDIR}${COMPFILE#.}"
-        if ln "${DESTDIR}/root/${COMPFILE##*/}" "${DESTDIR}${COMPFILE#.}"; then
+        unlink ${DESTDIR}/root/${COMPFILE##*/}
+        if ln ${DESTDIR}${COMPFILE#.} ${DESTDIR}/root/${COMPFILE##*/}; then
           echo "   *** Link from ${DESTDIR}${COMPFILE#.} to ${DESTDIR}/root/${COMPFILE##*/} installed successfully"
-          rm "${COMPFILE}"
         else
-          echo "   *** Error linking ${DESTDIR}${COMPFILE#.} to ${DESTDIR}/root/${COMPFILE##*/}, ${COMPFILE} will remain to install by hand"
+          echo "   *** Error linking ${DESTDIR}${COMPFILE#.} to ${DESTDIR}/root/${COMPFILE##*/}"
+          echo "   *** ${COMPFILE} will remain for your consideration"
         fi
         ;;
       *)
         echo "   *** ${COMPFILE} will remain for your consideration"
         ;;
       esac
-      DONT_INSTALL=yes
+      return
       ;;
     esac