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Re: [PATCH v2 2/3] t7800: fix tests when difftool uses --no-symlinks

From
John Keeping <john@keeping.me.uk>
Date
Mar 24, 2013, 15:15 UTC
Message-ID
<20130324151557.GB2286@serenity.lan>
In-Reply-To
<CAJELnLEhcY4Oc-EB=Mi7PKBQQF+EiVpW_dNH6G-abjZj0MAdNw@mail.gmail.com>
On Sun, Mar 24, 2013 at 09:31:45AM -0400, Matt McClure wrote:
Show 8 quoted lines
> On Sun, Mar 24, 2013 at 8:36 AM, John Keeping <john@keeping.me.uk> wrote:
> > In the
> > non-symlink case I think a user might find it surprising if the
> > (unmodified) file used by their diff tool were suddenly copied over the
> > working tree wiping out the changes they have just made.
> 
> That's exactly what I was describing here:
> http://thread.gmane.org/gmane.comp.version-control.git/217979/focus=218006

Ahh, I guess I didn't fully register the impact of that at the time and had to rediscover the problem for myself ;-)

How about doing this (on top of jk/difftool-dir-diff-edit-fix)?
-- >8 --
Subject: [PATCH] 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, store the initial hash of the working tree file 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.

Signed-off-by: John Keeping <john@keeping.me.uk>
---
 git-difftool.perl   | 35 +++++++++++++++++++++--------------
 t/t7800-difftool.sh | 26 ++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 14 deletions(-)
diff --git a/git-difftool.perl b/git-difftool.perl
index c433e86..be82b5a 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -15,7 +15,6 @@ use strict;
 use warnings;
 use File::Basename qw(dirname);
 use File::Copy;
-use File::Compare;
 use File::Find;
 use File::stat;
 use File::Path qw(mkpath rmtree);
@@ -123,7 +122,7 @@ sub setup_dir_diff
 	my $rindex = '';
 	my %submodule;
 	my %symlink;
-	my @working_tree = ();
+	my %working_tree;
 	my @rawdiff = split('\0', $diffrtn);
 
 	my $i = 0;
@@ -175,7 +174,9 @@ EOF
 
 		if ($rmode ne $null_mode) {
 			if (use_wt_file($repo, $workdir, $dst_path, $rsha1, $symlinks)) {
-				push(@working_tree, $dst_path);
+				$working_tree{$dst_path} =
+					$repo->command_oneline('hash-object',
+						"$workdir/$dst_path");
 			} else {
 				$rindex .= "$rmode $rsha1\t$dst_path\0";
 			}
@@ -227,7 +228,7 @@ EOF
 	# not part of the index. Remove any trailing slash from $workdir
 	# before starting to avoid double slashes in symlink targets.
 	$workdir =~ s|/$||;
-	for my $file (@working_tree) {
+	for my $file (keys %working_tree) {
 		my $dir = dirname($file);
 		unless (-d "$rdir/$dir") {
 			mkpath("$rdir/$dir") or
@@ -278,7 +279,7 @@ EOF
 		exit_cleanup($tmpdir, 1) if not $ok;
 	}
 
-	return ($ldir, $rdir, $tmpdir, @working_tree);
+	return ($ldir, $rdir, $tmpdir, %working_tree);
 }
 
 sub write_to_file
@@ -376,7 +377,7 @@ sub dir_diff
 	my $error = 0;
 	my $repo = Git->repository();
 	my $workdir = find_worktree($repo);
-	my ($a, $b, $tmpdir, @worktree) =
+	my ($a, $b, $tmpdir, %worktree) =
 		setup_dir_diff($repo, $workdir, $symlinks);
 
 	if (defined($extcmd)) {
@@ -390,19 +391,25 @@ 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.
-	for my $file (@worktree) {
+	for my $file (keys %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";
+		my $wt_hash = $repo->command_oneline('hash-object',
+			"$workdir/$file");
+		my $tmp_hash = $repo->command_oneline('hash-object',
+			"$b/$file");
+		my $wt_modified = $wt_hash ne $worktree{$file};
+		my $tmp_modified = $tmp_hash ne $worktree{$file};
+
+		if ($wt_modified and $tmp_modified) {
+			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 ($tmp_modified) {
 			my $mode = stat("$b/$file")->mode;
 			copy("$b/$file", "$workdir/$file") or
 			exit_cleanup($tmpdir, 1);
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index db3d3d6..be2042d 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -407,4 +407,30 @@ test_expect_success PERL 'difftool --dir-diff from subdirectory' '
 	)
 '
 
+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 "$2" >tmpdir
+EOF
+
+test_expect_success PERL 'difftool --no-symlinks detects conflict ' '
+	echo "orig content" >file &&
+	test_must_fail git difftool --dir-diff --no-symlinks --extcmd "$(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
-- 
1.8.2.411.g65a544e
Previous: Matt McClureNext: Johannes Sixt
Message 32 of 55 in “difftool: silence uninitialized variable warning”
  1. 1/4 difftool: silence uninitialized variable warningDavid Aguilar, Feb 21, 2013
  2. 2/4 t7800: update copyright noticeDavid Aguilar, Feb 21, 2013
  3. 3/4 t7800: modernize testsDavid Aguilar, Feb 21, 2013
  4. 4/4 t7800: "defaults" is no longer a builtin tool nameDavid Aguilar, Feb 21, 2013
  5. Junio C HamanoFeb 21, 2013
  6. Junio C HamanoFeb 21, 2013
  7. David AguilarFeb 21, 2013
  8. Johannes SixtMar 20, 2013
  9. David AguilarMar 20, 2013
  10. Johannes SixtMar 21, 2013
  11. Johannes SixtMar 22, 2013
  12. John KeepingMar 22, 2013
  13. Johannes SixtMar 22, 2013
  14. John KeepingMar 22, 2013
  15. 0/3 Improve difftool --dir-diff testsJohn Keeping, Mar 22, 2013
  16. 1/3 t7800: don't hide grep outputJohn Keeping, Mar 22, 2013
  17. Johannes SixtMar 22, 2013
  18. Junio C HamanoMar 22, 2013
  19. 2/3 t7800: fix tests when difftool uses --no-symlinksJohn Keeping, Mar 22, 2013
  20. Johannes SixtMar 22, 2013
  21. Junio C HamanoMar 22, 2013
  22. John KeepingMar 22, 2013
  23. David AguilarMar 23, 2013
  24. 3/3 t7800: run --dir-diff tests with and without symlinksJohn Keeping, Mar 22, 2013
  25. 3/3 t7800: run --dir-diff tests with and without symlinksJohn Keeping, Mar 22, 2013
  26. 0/3 difftool --dir-diff test improvementsJohn Keeping, Mar 23, 2013
  27. 1/3 t7800: don't hide grep outputJohn Keeping, Mar 23, 2013
  28. 2/3 t7800: fix tests when difftool uses --no-symlinksJohn Keeping, Mar 23, 2013
  29. Junio C HamanoMar 24, 2013
  30. John KeepingMar 24, 2013
  31. Matt McClureMar 24, 2013
  32. John KeepingMar 24, 2013
  33. Johannes SixtMar 25, 2013
  34. John KeepingMar 25, 2013
  35. difftool: don't overwrite modified filesJohn Keeping, Mar 25, 2013
  36. Johannes SixtMar 26, 2013
  37. Johannes SixtMar 26, 2013
  38. John KeepingMar 26, 2013
  39. Johannes SixtMar 26, 2013
  40. John KeepingMar 26, 2013
  41. Matt McClureMar 26, 2013
  42. John KeepingMar 26, 2013
  43. Junio C HamanoMar 25, 2013
  44. David AguilarMar 24, 2013
  45. John KeepingMar 25, 2013
  46. Junio C HamanoMar 25, 2013
  47. Matt McClureMar 24, 2013
  48. Eric SunshineMar 24, 2013
  49. 3/3 t7800: run --dir-diff tests with and without symlinksJohn Keeping, Mar 23, 2013
  50. Johannes SixtMar 25, 2013
  51. John KeepingMar 25, 2013
  52. Johannes SixtMar 25, 2013
  53. John KeepingMar 25, 2013
  54. Junio C HamanoMar 25, 2013
  55. John KeepingMar 26, 2013

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