difftool: don't overwrite modified files

After running the user's diff tool, git-difftool will copy any files
that differ between the working tree and the temporary tree.  This is
useful when the user edits the file in their diff tool but is wrong if
they edit the working tree file while examining the diff.

Instead of copying unconditionally when the files differ, create and
index from the working tree files and only copy the temporary file back
if it was modified and the working tree file was not.  If both files
have been modified, print a warning and exit with an error.

Note that we cannot use an existing index in git-difftool since those
contain the modified files that need to be checked out but here we are
looking at those files which are copied from the working tree and not
checked out.  These are precisely the files which are not in the
existing indices.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
John Keeping 2013-03-29 22:07:39 +00:00 committed by Junio C Hamano
parent bf341b902e
commit 67aa147af7
2 changed files with 101 additions and 14 deletions

View File

@ -13,9 +13,9 @@
use 5.008;
use strict;
use warnings;
use Error qw(:try);
use File::Basename qw(dirname);
use File::Copy;
use File::Compare;
use File::Find;
use File::stat;
use File::Path qw(mkpath rmtree);
@ -88,14 +88,45 @@ sub use_wt_file
my ($repo, $workdir, $file, $sha1, $symlinks) = @_;
my $null_sha1 = '0' x 40;
if ($sha1 eq $null_sha1) {
return 1;
} elsif (not $symlinks) {
if ($sha1 ne $null_sha1 and not $symlinks) {
return 0;
}
my $wt_sha1 = $repo->command_oneline('hash-object', "$workdir/$file");
return $sha1 eq $wt_sha1;
my $use = ($sha1 eq $null_sha1) || ($sha1 eq $wt_sha1);
return ($use, $wt_sha1);
}
sub changed_files
{
my ($repo_path, $index, $worktree) = @_;
$ENV{GIT_INDEX_FILE} = $index;
$ENV{GIT_WORK_TREE} = $worktree;
my $must_unset_git_dir = 0;
if (not defined($ENV{GIT_DIR})) {
$must_unset_git_dir = 1;
$ENV{GIT_DIR} = $repo_path;
}
my @refreshargs = qw/update-index --really-refresh -q --unmerged/;
my @gitargs = qw/diff-files --name-only -z/;
try {
Git::command_oneline(@refreshargs);
} catch Git::Error::Command with {};
my $line = Git::command_oneline(@gitargs);
my @files;
if (defined $line) {
@files = split('\0', $line);
} else {
@files = ();
}
delete($ENV{GIT_INDEX_FILE});
delete($ENV{GIT_WORK_TREE});
delete($ENV{GIT_DIR}) if ($must_unset_git_dir);
return map { $_ => 1 } @files;
}
sub setup_dir_diff
@ -121,6 +152,7 @@ sub setup_dir_diff
my $null_sha1 = '0' x 40;
my $lindex = '';
my $rindex = '';
my $wtindex = '';
my %submodule;
my %symlink;
my @working_tree = ();
@ -174,8 +206,12 @@ EOF
}
if ($rmode ne $null_mode) {
if (use_wt_file($repo, $workdir, $dst_path, $rsha1, $symlinks)) {
push(@working_tree, $dst_path);
my ($use, $wt_sha1) = use_wt_file($repo, $workdir,
$dst_path, $rsha1,
$symlinks);
if ($use) {
push @working_tree, $dst_path;
$wtindex .= "$rmode $wt_sha1\t$dst_path\0";
} else {
$rindex .= "$rmode $rsha1\t$dst_path\0";
}
@ -218,6 +254,12 @@ EOF
$rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
exit_cleanup($tmpdir, $rc) if $rc != 0;
$ENV{GIT_INDEX_FILE} = "$tmpdir/wtindex";
($inpipe, $ctx) =
$repo->command_input_pipe(qw(update-index --info-only -z --index-info));
print($inpipe $wtindex);
$repo->command_close_pipe($inpipe, $ctx);
# If $GIT_DIR was explicitly set just for the update/checkout
# commands, then it should be unset before continuing.
delete($ENV{GIT_DIR}) if ($must_unset_git_dir);
@ -390,19 +432,34 @@ sub dir_diff
# should be copied back to the working tree.
# Do not copy back files when symlinks are used and the
# external tool did not replace the original link with a file.
#
# These hashes are loaded lazily since they aren't needed
# in the common case of --symlinks and the difftool updating
# files through the symlink.
my %wt_modified;
my %tmp_modified;
my $indices_loaded = 0;
for my $file (@worktree) {
next if $symlinks && -l "$b/$file";
next if ! -f "$b/$file";
my $diff = compare("$b/$file", "$workdir/$file");
if ($diff == 0) {
next;
} elsif ($diff == -1) {
my $errmsg = "warning: Could not compare ";
$errmsg += "'$b/$file' with '$workdir/$file'\n";
if (!$indices_loaded) {
%wt_modified = changed_files($repo->repo_path(),
"$tmpdir/wtindex", "$workdir");
%tmp_modified = changed_files($repo->repo_path(),
"$tmpdir/wtindex", "$b");
$indices_loaded = 1;
}
if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
my $errmsg = "warning: Both files modified: ";
$errmsg .= "'$workdir/$file' and '$b/$file'.\n";
$errmsg .= "warning: Working tree file has been left.\n";
$errmsg .= "warning:\n";
warn $errmsg;
$error = 1;
} elsif ($diff == 1) {
} elsif (exists $tmp_modified{$file}) {
my $mode = stat("$b/$file")->mode;
copy("$b/$file", "$workdir/$file") or
exit_cleanup($tmpdir, 1);

View File

@ -377,4 +377,34 @@ test_expect_success PERL,SYMLINKS 'difftool --dir-diff --symlink without unstage
test_cmp actual expect
'
write_script modify-file <<\EOF
echo "new content" >file
EOF
test_expect_success PERL 'difftool --no-symlinks does not overwrite working tree file ' '
echo "orig content" >file &&
git difftool --dir-diff --no-symlinks --extcmd "$(pwd)/modify-file" branch &&
echo "new content" >expect &&
test_cmp expect file
'
write_script modify-both-files <<\EOF
echo "wt content" >file &&
echo "tmp content" >"$2/file" &&
echo "$2" >tmpdir
EOF
test_expect_success PERL 'difftool --no-symlinks detects conflict ' '
(
TMPDIR=$TRASH_DIRECTORY &&
export TMPDIR &&
echo "orig content" >file &&
test_must_fail git difftool --dir-diff --no-symlinks --extcmd "$(pwd)/modify-both-files" branch &&
echo "wt content" >expect &&
test_cmp expect file &&
echo "tmp content" >expect &&
test_cmp expect "$(cat tmpdir)/file"
)
'
test_done