[PATCH 1/3] difftool: sanitize $workdir as early as possible

[PATCH 1/3] difftool: sanitize $workdir as early as possible

[David Aguilar]

The double-slash fixup on the $workdir variable was being
performed just-in-time to avoid double-slashes in symlink
targets, but the rest of the code was silently using paths with
embedded "//" in them.

A recent user-reported error message contained double-slashes.
Eliminate the issue by sanitizing inputs as soon as they arrive.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 git-difftool.perl | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index 959822d5f3..17c336321f 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -224,9 +224,7 @@ EOF
 	delete($ENV{GIT_INDEX_FILE});
 
 	# Changes in the working tree need special treatment since they are
-	# not part of the index. Remove any trailing slash from $workdir
-	# before starting to avoid double slashes in symlink targets.
-	$workdir =~ s|/$||;
+	# not part of the index.
 	for my $file (@working_tree) {
 		my $dir = dirname($file);
 		unless (-d "$rdir/$dir") {
@@ -389,6 +387,7 @@ sub dir_diff
 	my $repo = Git->repository();
 	my $repo_path = $repo->repo_path();
 	my $workdir = $repo->wc_path();
+	$workdir =~ s|/$||; # Avoid double slashes in symlink targets
 	my ($a, $b, $tmpdir, @worktree) = setup_dir_diff($workdir, $symlinks);
 
 	if (defined($extcmd)) {
-- 
2.11.0.26.gb65c994

[PATCH 2/3] difftool: chdir as early as possible

[David Aguilar]

Make difftool chdir to the top-level of the repository as soon as it can
so that we can simplify how paths are handled.  Replace construction of
absolute paths via string concatenation with relative paths wherever
possible.  The bulk of the code no longer needs to use absolute paths.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 git-difftool.perl | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index 17c336321f..99b03949bf 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -59,14 +59,14 @@ sub exit_cleanup
 
 sub use_wt_file
 {
-	my ($workdir, $file, $sha1) = @_;
+	my ($file, $sha1) = @_;
 	my $null_sha1 = '0' x 40;
 
-	if (-l "$workdir/$file" || ! -e _) {
+	if (-l $file || ! -e _) {
 		return (0, $null_sha1);
 	}
 
-	my $wt_sha1 = Git::command_oneline('hash-object', "$workdir/$file");
+	my $wt_sha1 = Git::command_oneline('hash-object', $file);
 	my $use = ($sha1 eq $null_sha1) || ($sha1 eq $wt_sha1);
 	return ($use, $wt_sha1);
 }
@@ -105,6 +105,12 @@ sub setup_dir_diff
 	my $diffrtn = Git::command_oneline(@gitargs);
 	exit(0) unless defined($diffrtn);
 
+	# Go to the root of the worktree now that we've captured the list of
+	# changed files.  The paths returned by diff --raw are relative to the
+	# top-level of the repository, but we defer changing directories so
+	# that @ARGV can perform pathspec limiting in the current directory.
+	chdir($workdir);
+
 	# Build index info for left and right sides of the diff
 	my $submodule_mode = '160000';
 	my $symlink_mode = '120000';
@@ -172,7 +178,7 @@ EOF
 				next;
 			}
 			my ($use, $wt_sha1) =
-				use_wt_file($workdir, $dst_path, $rsha1);
+				use_wt_file($dst_path, $rsha1);
 			if ($use) {
 				push @working_tree, $dst_path;
 				$wtindex .= "$rmode $wt_sha1\t$dst_path\0";
@@ -182,10 +188,6 @@ EOF
 		}
 	}
 
-	# Go to the root of the worktree so that the left index files
-	# are properly setup -- the index is toplevel-relative.
-	chdir($workdir);
-
 	# Setup temp directories
 	my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 0, TMPDIR => 1);
 	my $ldir = "$tmpdir/left";
@@ -235,10 +237,10 @@ EOF
 			symlink("$workdir/$file", "$rdir/$file") or
 			exit_cleanup($tmpdir, 1);
 		} else {
-			copy("$workdir/$file", "$rdir/$file") or
+			copy($file, "$rdir/$file") or
 			exit_cleanup($tmpdir, 1);
 
-			my $mode = stat("$workdir/$file")->mode;
+			my $mode = stat($file)->mode;
 			chmod($mode, "$rdir/$file") or
 			exit_cleanup($tmpdir, 1);
 		}
@@ -430,10 +432,10 @@ sub dir_diff
 			$error = 1;
 		} elsif (exists $tmp_modified{$file}) {
 			my $mode = stat("$b/$file")->mode;
-			copy("$b/$file", "$workdir/$file") or
+			copy("$b/$file", $file) or
 			exit_cleanup($tmpdir, 1);
 
-			chmod($mode, "$workdir/$file") or
+			chmod($mode, $file) or
 			exit_cleanup($tmpdir, 1);
 		}
 	}
-- 
2.11.0.26.gb65c994

Re: [PATCH 2/3] difftool: chdir as early as possible

[Junio C Hamano]

David Aguilar <davvid@gmail.com> writes:

> @@ -182,10 +188,6 @@ EOF
>  		}
>  	}
>  
> -	# Go to the root of the worktree so that the left index files
> -	# are properly setup -- the index is toplevel-relative.
> -	chdir($workdir);
> -
>  	# Setup temp directories
>  	my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 0, TMPDIR => 1);
>  	my $ldir = "$tmpdir/left";

What codebase are you basing your work on?  I do not see these
removed four lines in my tree, so it seems that the patch is fixing
up some other fix I do not yet have.

> @@ -235,10 +237,10 @@ EOF
>  			symlink("$workdir/$file", "$rdir/$file") or
>  			exit_cleanup($tmpdir, 1);
>  		} else {
> -			copy("$workdir/$file", "$rdir/$file") or
> +			copy($file, "$rdir/$file") or
>  			exit_cleanup($tmpdir, 1);
>  
> -			my $mode = stat("$workdir/$file")->mode;
> +			my $mode = stat($file)->mode;
>  			chmod($mode, "$rdir/$file") or
>  			exit_cleanup($tmpdir, 1);
>  		}
> @@ -430,10 +432,10 @@ sub dir_diff
>  			$error = 1;
>  		} elsif (exists $tmp_modified{$file}) {
>  			my $mode = stat("$b/$file")->mode;
> -			copy("$b/$file", "$workdir/$file") or
> +			copy("$b/$file", $file) or
>  			exit_cleanup($tmpdir, 1);
>  
> -			chmod($mode, "$workdir/$file") or
> +			chmod($mode, $file) or
>  			exit_cleanup($tmpdir, 1);
>  		}
>  	}

Re: [PATCH 2/3] difftool: chdir as early as possible

[David Aguilar]

On Fri, Dec 09, 2016 at 03:02:09PM -0800, Junio C Hamano wrote:
> David Aguilar <davvid@gmail.com> writes:
> 
> > @@ -182,10 +188,6 @@ EOF
> >  		}
> >  	}
> >  
> > -	# Go to the root of the worktree so that the left index files
> > -	# are properly setup -- the index is toplevel-relative.
> > -	chdir($workdir);
> > -
> >  	# Setup temp directories
> >  	my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 0, TMPDIR => 1);
> >  	my $ldir = "$tmpdir/left";
> 
> What codebase are you basing your work on?  I do not see these
> removed four lines in my tree, so it seems that the patch is fixing
> up some other fix I do not yet have.

Sorry about that.

I forgot to mention that this is based on the patches I recently
sent, which were in the "pu" branch.  The whats-cooking report
mentioned that they'll be merged to "next", so they might be
there already too.

The patch this was based upon:

difftool: fix dir-diff index creation when in a subdirectory
-- 
David

[PATCH 3/3] difftool: rename variables for consistency

[David Aguilar]

Always call the list of files @files.
Always call the worktree $worktree.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 git-difftool.perl | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index 99b03949bf..4e4f5d8138 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -100,7 +100,7 @@ sub changed_files
 
 sub setup_dir_diff
 {
-	my ($workdir, $symlinks) = @_;
+	my ($worktree, $symlinks) = @_;
 	my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
 	my $diffrtn = Git::command_oneline(@gitargs);
 	exit(0) unless defined($diffrtn);
@@ -109,7 +109,7 @@ sub setup_dir_diff
 	# changed files.  The paths returned by diff --raw are relative to the
 	# top-level of the repository, but we defer changing directories so
 	# that @ARGV can perform pathspec limiting in the current directory.
-	chdir($workdir);
+	chdir($worktree);
 
 	# Build index info for left and right sides of the diff
 	my $submodule_mode = '160000';
@@ -121,7 +121,7 @@ sub setup_dir_diff
 	my $wtindex = '';
 	my %submodule;
 	my %symlink;
-	my @working_tree = ();
+	my @files = ();
 	my %working_tree_dups = ();
 	my @rawdiff = split('\0', $diffrtn);
 
@@ -173,14 +173,14 @@ EOF
 		}
 
 		if ($rmode ne $null_mode) {
-			# Avoid duplicate working_tree entries
+			# Avoid duplicate entries
 			if ($working_tree_dups{$dst_path}++) {
 				next;
 			}
 			my ($use, $wt_sha1) =
 				use_wt_file($dst_path, $rsha1);
 			if ($use) {
-				push @working_tree, $dst_path;
+				push @files, $dst_path;
 				$wtindex .= "$rmode $wt_sha1\t$dst_path\0";
 			} else {
 				$rindex .= "$rmode $rsha1\t$dst_path\0";
@@ -227,14 +227,14 @@ EOF
 
 	# Changes in the working tree need special treatment since they are
 	# not part of the index.
-	for my $file (@working_tree) {
+	for my $file (@files) {
 		my $dir = dirname($file);
 		unless (-d "$rdir/$dir") {
 			mkpath("$rdir/$dir") or
 			exit_cleanup($tmpdir, 1);
 		}
 		if ($symlinks) {
-			symlink("$workdir/$file", "$rdir/$file") or
+			symlink("$worktree/$file", "$rdir/$file") or
 			exit_cleanup($tmpdir, 1);
 		} else {
 			copy($file, "$rdir/$file") or
@@ -278,7 +278,7 @@ EOF
 		exit_cleanup($tmpdir, 1) if not $ok;
 	}
 
-	return ($ldir, $rdir, $tmpdir, @working_tree);
+	return ($ldir, $rdir, $tmpdir, @files);
 }
 
 sub write_to_file
@@ -388,9 +388,9 @@ sub dir_diff
 	my $error = 0;
 	my $repo = Git->repository();
 	my $repo_path = $repo->repo_path();
-	my $workdir = $repo->wc_path();
-	$workdir =~ s|/$||; # Avoid double slashes in symlink targets
-	my ($a, $b, $tmpdir, @worktree) = setup_dir_diff($workdir, $symlinks);
+	my $worktree = $repo->wc_path();
+	$worktree =~ s|/$||; # Avoid double slashes in symlink targets
+	my ($a, $b, $tmpdir, @files) = setup_dir_diff($worktree, $symlinks);
 
 	if (defined($extcmd)) {
 		$rc = system($extcmd, $a, $b);
@@ -411,13 +411,13 @@ sub dir_diff
 	my %tmp_modified;
 	my $indices_loaded = 0;
 
-	for my $file (@worktree) {
+	for my $file (@files) {
 		next if $symlinks && -l "$b/$file";
 		next if ! -f "$b/$file";
 
 		if (!$indices_loaded) {
 			%wt_modified = changed_files(
-				$repo_path, "$tmpdir/wtindex", $workdir);
+				$repo_path, "$tmpdir/wtindex", $worktree);
 			%tmp_modified = changed_files(
 				$repo_path, "$tmpdir/wtindex", $b);
 			$indices_loaded = 1;
@@ -425,7 +425,7 @@ sub dir_diff
 
 		if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
 			my $errmsg = "warning: Both files modified: ";
-			$errmsg .= "'$workdir/$file' and '$b/$file'.\n";
+			$errmsg .= "'$worktree/$file' and '$b/$file'.\n";
 			$errmsg .= "warning: Working tree file has been left.\n";
 			$errmsg .= "warning:\n";
 			warn $errmsg;
-- 
2.11.0.26.gb65c994