Re: Conflict editing

From: Theodore Tso <tytso@mit.edu>
Date: Mar 4, 2007, 18:10 UTC
Message-ID: <20070304181044.GC8560@thunk.org>
In-Reply-To: <Pine.LNX.4.63.0703041339350.22628@wbgn013.biozentrum.uni-wuerzburg.de>

On Sun, Mar 04, 2007 at 01:43:59PM +0100, Johannes Schindelin wrote:

Show 8 quoted lines

> I often end up with conflicts, and I just want to edit the conflicting 
> files, one after another. To make this easier, I wrote a script (yes, no 
> builtin) to start the editor with the files having conflicts.
> 
> Of course, this script is dumb and has no way to edit files whose names 
> contain spaces, it will choke on conflicting symlinks and it does not 
> update the index after editing the files (to avoid erroneous updating). As 
> usual, it did not really receive more testing than absolutely necessary.

As it turns out, I've been working on my own script, git-mergetool, to deal with conflicts, and while it isn't quite ready for prime time yet (no documentation, doesn't deal with filenames with spaces yet, etc.) it does fire up the GUI merge tools and it does update the index afterwards. My intention is to polish this up and submit this into a patch to git.

The goal is to have similar functionality to what Bitkeeper and Mercurial have as far as GUI merge tools are concerned. Once I am done polishing git-mergetool, I'll likely submit a patch to enable a config option which will cause "git merge" to automatically fire up "git mergetool" if there are any conflicts.

The patch doesn't current fall back to firing up an editor, but in order to subsume Johannes' script's functionality, I will probably add that functionality with code that looks for merge markers and which only does the "git add" if the merge markers are completely gone.

It currently uses a hard-wired preference order for the GUI merge tools, based on the current functionality of said merge tools, but the plan is to add options parsing and a config option to allow a user-specified override.

Any comments, suggestions?

						- Ted

#!/bin/sh # # This program resolves merge conflicts in git #

KDIFF3="kdiff3" TKDIFF="tkdiff" MELD="meld"

type "$KDIFF3" >/dev/null 2>&1 || KDIFF3= type "$TKDIFF" >/dev/null 2>&1 || TKDIFF= type "$MELD" >/dev/null 2>&1 || MELD=

if test -z "$KDIFF3" -a -z "$TKDIFF" -a -z "$MELD" ; then
	echo "No available GUI merge tools available."
	exit 1
fi

merge_file () {
	path="$1"

	if test ! -f "$path" ; then
		echo "$path: file not found"
		exit 1
	fi

	f=`git-ls-files -u "$path"`
	if test -z "$f" ; then
		echo "$path: file does not need merging"
		exit 1
	fi

	BACKUP="$path.BACKUP.$$"
	LOCAL="$path.LOCAL.$$"
	REMOTE="$path.REMOTE.$$"
	BASE="$path.BASE.$$"
	CHGTEST="$LOCAL.chg.$RAND"

	mv $path $BACKUP
	cp $BACKUP $path

	git show :1:$path > "$BASE"
	git show :2:$path > "$LOCAL"
	git show :3:$path > "$REMOTE"

	if test -n "$KDIFF3" ; then
		kdiff3 --auto "$BASE" "$LOCAL" "$REMOTE" -o "$path"
		status=$?
	elif test -n "$TKDIFF" ; then
		tkdiff "$LOCAL" "$REMOTE" -a "$BASE" -o "$path"
		status=$?
	elif test -n "$MELD" ; then
		meld "$LOCAL" "$path" "$REMOTE"
		if test "$path" -nt "$BACKUP" ; then 
			status=0;
		else
			while true; do
			        echo "$path seems unchanged."
			        echo -n "Was the merge successful? [y/n] "
			        read answer
			        case "$answer" in
			        	y*|Y*) status=0; break ;;
					n*|N*) status=1; break ;;
				esac
			done
		fi
	fi
	rm -f "$LOCAL" "$REMOTE" "$BASE"
	if test $status != 0 ; then
		echo "merge of $path failed" 1>&2
		mv "$BACKUP" $path
		exit 1
	fi
	git add $path
}

if test $# -eq 0 ; then
	files=`git ls-files -u --abbrev=8 | colrm 1 24 | sort -u`
	if test -z "$files" ; then
		echo "No files need merging"
		exit 0
	fi
	echo Merging the files: $files
	for i in `git ls-files -u --abbrev=8 | colrm 1 24 | sort -u`
	do
		merge_file "$i"
	done
else
	while test $# -gt 0; do
		merge_file "$1"
		shift
	done
fi
exit 0