Teach 'diff' about 'diff' attribute.

diff --git a/git-merge-one-file.sh b/git-merge-one-file.sh
index 5349a1c0fc54eb0b7feaf6192d20b6c6b2ab5e3b..7d62d7902cb1d7cd2749091b86d532306bea89b3 100755 (executable)
--- a/git-merge-one-file.sh
+++ b/git-merge-one-file.sh
@@ -8,7 +8,7 @@
 #   $2 - file in branch1 SHA1 (or empty)
 #   $3 - file in branch2 SHA1 (or empty)
 #   $4 - pathname in repository
-#   $5 - orignal file mode (or empty)
+#   $5 - original file mode (or empty)
 #   $6 - file in branch1 mode (or empty)
 #   $7 - file in branch2 mode (or empty)
 #
@@ -23,10 +23,16 @@ case "${1:-.}${2:-.}${3:-.}" in
 "$1.." | "$1.$1" | "$1$1.")
        if [ "$2" ]; then
                echo "Removing $4"
+       else
+               # read-tree checked that index matches HEAD already,
+               # so we know we do not have this path tracked.
+               # there may be an unrelated working tree file here,
+               # which we should just leave unmolested.
+               exit 0
        fi
        if test -f "$4"; then
                rm -f -- "$4" &&
-               rmdir -p "$(expr "$4" : '\(.*\)/')" 2>/dev/null || :
+               rmdir -p "$(expr "z$4" : 'z\(.*\)/')" 2>/dev/null || :
        fi &&
                exec git-update-index --remove -- "$4"
        ;;
@@ -34,8 +40,16 @@ case "${1:-.}${2:-.}${3:-.}" in
 #
 # Added in one.
 #
-".$2." | "..$3" )
+".$2.")
+       # the other side did not add and we added so there is nothing
+       # to be done.
+       ;;
+"..$3")
        echo "Adding $4"
+       test -f "$4" || {
+               echo "ERROR: untracked $4 is overwritten by the merge."
+               exit 1
+       }
        git-update-index --add --cacheinfo "$6$7" "$2$3" "$4" &&
                exec git-checkout-index -u -f -- "$4"
        ;;
@@ -90,7 +104,7 @@ case "${1:-.}${2:-.}${3:-.}" in
        # Be careful for funny filename such as "-L" in "$4", which
        # would confuse "merge" greatly.
        src1=`git-unpack-file $2`
-       merge "$src1" "$orig" "$src2"
+       git-merge-file "$src1" "$orig" "$src2"
        ret=$?
 
        # Create the working tree file, using "our tree" version from the