[PATCH] allow merging any committish

diff --git a/git-merge-one-file.sh b/git-merge-one-file.sh
index d9ee4581504984e4337a70433f82c411bb5a9c02..7dee88a73370d9aa00e41ca290f2c6a589c77d90 100755 (executable)
--- a/git-merge-one-file.sh
+++ b/git-merge-one-file.sh
@@ -25,7 +25,8 @@ case "${1:-.}${2:-.}${3:-.}" in
                echo "Removing $4"
        fi
        if test -f "$4"; then
-               rm -f -- "$4"
+               rm -f -- "$4" &&
+               rmdir -p "$(expr "$4" : '\(.*\)/')" 2>/dev/null || :
        fi &&
                exec git-update-index --remove -- "$4"
        ;;
@@ -57,6 +58,14 @@ case "${1:-.}${2:-.}${3:-.}" in
 # Modified in both, but differently.
 #
 "$1$2$3" | ".$2$3")
+
+       case ",$6,$7," in
+       *,120000,*)
+               echo "ERROR: $4: Not merging symbolic link changes."
+               exit 1
+               ;;
+       esac
+
        src2=`git-unpack-file $3`
        case "$1" in
        '')
@@ -64,7 +73,13 @@ case "${1:-.}${2:-.}${3:-.}" in
                # This extracts OUR file in $orig, and uses git-apply to
                # remove lines that are unique to ours.
                orig=`git-unpack-file $2`
+               sz0=`wc -c <"$orig"`
                diff -u -La/$orig -Lb/$orig $orig $src2 | git-apply --no-add 
+               sz1=`wc -c <"$orig"`
+
+               # If we do not have enough common material, it is not
+               # worth trying two-file merge using common subsections.
+               expr "$sz0" \< "$sz1" \* 2 >/dev/null || : >$orig
                ;;
        *)
                echo "Auto-merging $4."
@@ -72,13 +87,16 @@ case "${1:-.}${2:-.}${3:-.}" in
                ;;
        esac
 
-       # We reset the index to the first branch, making
-       # git-diff-file useful
-       git-update-index --add --cacheinfo "$6" "$2" "$4"
-               git-checkout-index -u -f -- "$4" &&
-               merge "$4" "$orig" "$src2"
+       # Be careful for funny filename such as "-L" in "$4", which
+       # would confuse "merge" greatly.
+       src1=`git-unpack-file $2`
+       merge "$src1" "$orig" "$src2"
        ret=$?
-       rm -f -- "$orig" "$src2"
+
+       # Create the working tree file, using "our tree" version from the
+       # index, and then store the result of the merge.
+       git-checkout-index -f --stage=2 -- "$4" && cat "$src1" >"$4"
+       rm -f -- "$orig" "$src1" "$src2"
 
        if [ "$6" != "$7" ]; then
                echo "ERROR: Permissions conflict: $5->$6,$7."