https://github.com/git/git
Revision 531942d353758305e29879654b93f4ba3dcbcc63 authored by Elijah Newren on 28 September 2020, 17:37:16 UTC, committed by Elijah Newren on 13 October 2020, 22:37:51 UTC
Testcases 12b and 12c were both slightly weird; they were marked as having a weird resolution, but with the note that even straightforward simple rules can give weird results when the input is bizarre. However, during optimization work for merge-ort, I discovered a significant speedup that is possible if we add one more fairly straightforward rule: we don't bother doing directory rename detection if there are no new files added to the directory on the other side of the history to be affected by the directory rename. This seems like an obvious and straightforward rule, but there was one funny corner case where directory rename detection could affect only existing files: the funny corner case where two directories are renamed into each other on opposite sides of history. In other words, it only results in a different output for testcases 12b and 12c. Since we already thought testcases 12b and 12c were weird anyway, and because the optimization often has a significant effect on common cases (but is entirely prevented if we can't change how 12b and 12c function), let's add the additional rule and tweak how 12b and 12c work. Split both testcases into two (one where we add no new files, and one where the side that doesn't rename a given directory will add files to it), and mark them with the new expectation. Signed-off-by: Elijah Newren <newren@gmail.com>
1 parent 146d6f4
Tip revision: 531942d353758305e29879654b93f4ba3dcbcc63 authored by Elijah Newren on 28 September 2020, 17:37:16 UTC
t6423: more involved rules for renaming directories into each other
t6423: more involved rules for renaming directories into each other
Tip revision: 531942d
git-merge-one-file.sh
#!/bin/sh
#
# Copyright (c) Linus Torvalds, 2005
#
# 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 -- "$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 $(git hash-object /dev/null))
;;
*)
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
echo "ERROR: $msg in $4" >&2
exit 1
fi
exec git update-index -- "$4"
;;
*)
echo "ERROR: $4: Not handling case $1 -> $2 -> $3" >&2
;;
esac
exit 1
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