Original "git-merge-one-file" script is slightly tweaked here into
"git-merge-one-file--cached"[*1*] to allow (still trivial) _index-only_
three-way file merge, not touching files inside working tree.
Proof of concept, not thoroughly tested, original content left in,
commented out. Feel free to comment/polish.
To make it available, I guess it would be best placed beside existing
"git-merge-one-file" script...?
Regards, Buga
[*1*] "git-merge-one-file--cached"
--- 8< ---
#!/bin/sh
#
# Copyright (c) Linus Torvalds, 2005
#
# ---
# Original "git-merge-one-file" script slightly tweaked into
# "git-merge-one-file--cached" to allow (still trivial) index-only
# three-way file merge, not touching files inside working tree.
#
# Proof of concept, not thoroughly tested, original content left in,
# commented out.
# ---
#
# This is the git per-file merge script, called with
#
# $1 - original file SHA1 (or empty)
# $2 - file in branch1 SHA1 (or empty)
# $3 - file in branch2 SHA1 (or empty)
# $4 - pathname in repository
# $5 - original file mode (or empty)
# $6 - file in branch1 mode (or empty)
# $7 - file in branch2 mode (or empty)
#
# Handle some trivial cases.. The _really_ trivial cases have
# been handled already by git read-tree, but that one doesn't
# do any merges that might change the tree layout.
USAGE='<orig blob> <our blob> <their blob> <path>'
USAGE="$USAGE <orig mode> <our mode> <their mode>"
LONG_USAGE="usage: git merge-one-file $USAGE
Blob ids and modes should be empty for missing files."
SUBDIRECTORY_OK=Yes
. git-sh-setup
cd_to_toplevel
require_work_tree
if test $# != 7
then
echo "$LONG_USAGE"
exit 1
fi
case "${1:-.}${2:-.}${3:-.}" in
#
# Deleted in both or deleted in one and unchanged in the other
#
"$1.." | "$1.$1" | "$1$1.")
if { test -z "$6" && test "$5" != "$7"; } ||
{ test -z "$7" && test "$5" != "$6"; }
then
echo "ERROR: File $4 deleted on one branch but had its" >&2
echo "ERROR: permissions changed on the other." >&2
exit 1
fi
if test -n "$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. Make sure
# we do not have it in the index, though.
# exec git update-index --remove -- "$4"
fi
# if test -f "$4"
# then
# rm -f -- "$4" &&
# rmdir -p "$(expr "z$4" : 'z\(.*\)/')" 2>/dev/null || :
# fi &&
exec git update-index --remove --cacheinfo "$6","$2","$4"
;;
#
# Added in one.
#
".$2.")
# the other side did not add and we added so there is nothing
# to be done, except making the path merged.
exec git update-index --add --cacheinfo "$6","$2","$4"
;;
"..$3")
echo "Adding $4"
if test -f "$4"
then
echo "ERROR: untracked $4 is overwritten by the merge." >&2
exit 1
fi
git update-index --add --cacheinfo "$7","$3","$4" # &&
# exec git checkout-index -u -f -- "$4"
;;
#
# Added in both, identically (check for same permissions).
#
".$3$2")
if test "$6" != "$7"
then
echo "ERROR: File $4 added identically in both branches," >&2
echo "ERROR: but permissions conflict $6->$7." >&2
exit 1
fi
echo "Adding $4"
git update-index --add --cacheinfo "$6","$2","$4" # &&
# exec git checkout-index -u -f -- "$4"
;;
#
# Modified in both, but differently.
#
"$1$2$3" | ".$2$3")
case ",$6,$7," in
*,120000,*)
echo "ERROR: $4: Not merging symbolic link changes." >&2
exit 1
;;
*,160000,*)
echo "ERROR: $4: Not merging conflicting submodule changes." >&2
exit 1
;;
esac
src1=$(git unpack-file $2)
src2=$(git unpack-file $3)
case "$1" in
'')
echo "Added $4 in both, but differently."
orig=$(git unpack-file e69de29bb2d1d6434b8b29ae775ad8c2e48c5391)
;;
*)
echo "Auto-merging $4"
orig=$(git unpack-file $1)
;;
esac
git merge-file "$src1" "$orig" "$src2"
ret=$?
msg=
if test $ret != 0 || test -z "$1"
then
msg='content conflict'
ret=1
fi
# 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" >"$4" || exit 1
# rm -f -- "$orig" "$src1" "$src2"
if test "$6" != "$7"
then
if test -n "$msg"
then
msg="$msg, "
fi
msg="${msg}permissions conflict: $5->$6,$7"
ret=1
fi
if test $ret = 0
then
merge_blob=$(git hash-object -w --path="$4" -- "$src1")
fi
rm -f -- "$orig" "$src1" "$src2"
if test $ret != 0
then
echo "ERROR: $msg in $4" >&2
exit 1
fi
# exec git update-index -- "$4"
exec git update-index --cacheinfo "$6","$merge_blob","$4"
;;
*)
echo "ERROR: $4: Not handling case $1 -> $2 -> $3" >&2
;;
esac
exit 1
