Update git-merge-one-file-script.

With this change, git-merge-one-file-script ceases to smudge
files in the work tree when recording the trivial merge results
(conflicting auto-merge failure case does not touch the work
tree file as before).

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/git-merge-one-file-script b/git-merge-one-file-script
index cefbe63..3fb43cc 100755 (executable)
--- a/git-merge-one-file-script
+++ b/git-merge-one-file-script
@@ -6,81 +6,69 @@
 #   $2 - file in branch1 SHA1 (or empty)
 #   $3 - file in branch2 SHA1 (or empty)
 #   $4 - pathname in repository
-#
+#   $5 - orignal file mode (or empty)
+#   $6 - file in branch1 mode (or empty)
+#   $7 - file in branch2 mode (or empty)
 #
 # Handle some trivial cases.. The _really_ trivial cases have
 # been handled already by git-read-tree, but that one doesn't
-# do any merges that migth change the tree layout
-#
-
-# if the directory is newly added in a branch, it might not exist
-# in the current tree
-dir=$(dirname "$4")
-mkdir -p "$dir" || exit
+# do any merges that migth change the tree layout.
 
 case "${1:-.}${2:-.}${3:-.}" in
 #
-# deleted in both
+# Deleted in both.
 #
 "$1..")
-       echo "ERROR: $4 is removed in both branches"
-       echo "ERROR: This is a potential rename conflict"
+       echo "ERROR: $4 is removed in both branches."
+       echo "ERROR: This is a potential rename conflict."
        exit 1;;
 #
-# deleted in one and unchanged in the other
+# Deleted in one and unchanged in the other.
 #
 "$1.." | "$1.$1" | "$1$1.")
        echo "Removing $4"
-       rm -f -- "$4" && exec git-update-cache --remove -- "$4" ;;
+       exec git-update-cache --force-remove "$4" ;;
 #
-# added in one
+# Added in one.
 #
 ".$2." | "..$3" )
        case "$6$7" in *7??) mode=+x;; *) mode=-x;; esac
-       echo "Adding $4 with perm $mode"
-       rm -f -- "$4" &&
-       git-cat-file blob "$2$3" >"$4" &&
-       chmod "$mode" -- "$4" &&
-       exec git-update-cache --add -- "$4" ;;
+       echo "Adding $4 with perm $mode."
+       exec git-update-cache --add --cacheinfo "$6$7" "$2$3" "$4" ;;
 #
-# Added in both (check for same permissions)
+# Added in both (check for same permissions).
 #
-".$2$2")
+".$3$2")
        if [ "$6" != "$7" ]; then
-               echo "ERROR: File $4 added in both branches, permissions conflict $6->$7"
+               echo "ERROR: File $4 added identically in both branches,"
+               echo "ERROR: but permissions conflict $6->$7."
                exit 1
        fi
        case "$6" in *7??) mode=+x;; *) mode=-x;; esac
        echo "Adding $4 with perm $mode"
-       rm -f -- "$4" &&
-       git-cat-file blob "$2" >"$4" &&
-       chmod "$mode" -- "$4" &&
-       exec git-update-cache --add -- "$4" ;;
+       exec git-update-cache --add --cacheinfo "$6" "$2" "$4" ;;
 #
-# Modified in both, but differently ;(
+# Modified in both, but differently.
 #
 "$1$2$3")
-       echo "Auto-merging $4"
+       echo "Auto-merging $4."
        orig=$(git-unpack-file $1)
        src1=$(git-unpack-file $2)
        src2=$(git-unpack-file $3)
        merge "$src2" "$orig" "$src1"
        ret=$?
        if [ "$6" != "$7" ]; then
-               echo "ERROR: Permissions $5->$6->$7 don't match merging $src2"
-               if [ $ret -ne 0 ]; then
-                       echo "ERROR: Leaving conflict merge in $src2"
-               fi
-               exit 1
+               echo "ERROR: Permissions $5->$6->$7 don't match."
        fi
        if [ $ret -ne 0 ]; then
-               echo "ERROR: Leaving conflict merge in $src2"
+               echo "ERROR: Leaving conflict merge in $src2."
                exit 1
        fi
-       case "$6" in *7??) mode=+x;; *) mode=-x;; esac
-       rm -f -- "$4" && cat "$src2" >"$4" && chmod "$mode" -- "$4" &&
-       exec git-update-cache --add -- "$4" ;;
+       sha1=$(git-write-blob "$src2") || {
+               echo "ERROR: Leaving conflict merge in $src2."
+       }
+       exec git-update-cache --add --cacheinfo "$6" $sha1 "$4" ;;
 *)
-       echo "Not handling case $4: $1 -> $2 -> $3" ;;
+       echo "ERROR: Not handling case $4: $1 -> $2 -> $3" ;;
 esac
 exit 1