Merge branch 'jk/difftool-dir-diff-edit-fix'

"git difftool --dir-diff" made symlinks to working tree files when
preparing a temporary directory structure, so that accidental edits
of these files in the difftool are reflected back to the working
tree, but the logic to decide when to do so was not quite right.

* jk/difftool-dir-diff-edit-fix:
difftool --dir-diff: symlink all files matching the working tree
difftool: avoid double slashes in symlink targets
git-difftool(1): fix formatting of --symlink description

diff --combined git-difftool.perl
index 12231fbc6708971f6350006c710124bd369de7ab,c433e86f09e9c10e2bf94d7e5cc61364a33aab2b..663640d33cb99a98135b38b95947416b4a8d49b9
--- 1/git-difftool.perl
--- 2/git-difftool.perl
+++ b/git-difftool.perl
@@@ -83,6 -83,21 +83,21 @@@ sub exit_cleanu
        exit($status | ($status >> 8));
  }
  
+ 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) {
+               return 0;
+       }
+ 
+       my $wt_sha1 = $repo->command_oneline('hash-object', "$workdir/$file");
+       return $sha1 eq $wt_sha1;
+ }
+ 
  sub setup_dir_diff
  {
        my ($repo, $workdir, $symlinks) = @_;
@@@ -159,10 -174,10 +174,10 @@@ EO
                }
  
                if ($rmode ne $null_mode) {
-                       if ($rsha1 ne $null_sha1) {
-                               $rindex .= "$rmode $rsha1\t$dst_path\0";
-                       } else {
+                       if (use_wt_file($repo, $workdir, $dst_path, $rsha1, $symlinks)) {
                                push(@working_tree, $dst_path);
+                       } else {
+                               $rindex .= "$rmode $rsha1\t$dst_path\0";
                        }
                }
        }
@@@ -209,7 -224,9 +224,9 @@@
        delete($ENV{GIT_INDEX_FILE});
  
        # Changes in the working tree need special treatment since they are
-       # not part of the index
+       # 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) {
                my $dir = dirname($file);
                unless (-d "$rdir/$dir") {
@@@ -336,7 -353,7 +353,7 @@@ sub mai
        }
        if ($opts{gui}) {
                my $guitool = Git::config('diff.guitool');
 -              if (length($guitool) > 0) {
 +              if (defined($guitool) && length($guitool) > 0) {
                        $ENV{GIT_DIFF_TOOL} = $guitool;
                }
        }

diff --combined t/t7800-difftool.sh
index 3aab6e15000f57e76d05f70920525d5734e20ef7,db3d3d6bd1d8a979ee757bb7faca0adec853485b..c6d6b1c99fe98b7dc692eaf3828a08696bfb5e10
--- 1/t/t7800-difftool.sh
--- 2/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@@ -1,6 -1,6 +1,6 @@@
  #!/bin/sh
  #
 -# Copyright (c) 2009, 2010 David Aguilar
 +# Copyright (c) 2009, 2010, 2012, 2013 David Aguilar
  #
  
  test_description='git-difftool
@@@ -10,25 -10,43 +10,25 @@@ Testing basic diff tool invocatio
  
  . ./test-lib.sh
  
 -remove_config_vars()
 +difftool_test_setup ()
  {
 -      # Unset all config variables used by git-difftool
 -      git config --unset diff.tool
 -      git config --unset diff.guitool
 -      git config --unset difftool.test-tool.cmd
 -      git config --unset difftool.prompt
 -      git config --unset merge.tool
 -      git config --unset mergetool.test-tool.cmd
 -      git config --unset mergetool.prompt
 -      return 0
 +      test_config diff.tool test-tool &&
 +      test_config difftool.test-tool.cmd 'cat "$LOCAL"' &&
 +      test_config difftool.bogus-tool.cmd false
  }
  
 -restore_test_defaults()
 -{
 -      # Restores the test defaults used by several tests
 -      remove_config_vars
 -      unset GIT_DIFF_TOOL
 -      unset GIT_DIFFTOOL_PROMPT
 -      unset GIT_DIFFTOOL_NO_PROMPT
 -      git config diff.tool test-tool &&
 -      git config difftool.test-tool.cmd 'cat $LOCAL'
 -      git config difftool.bogus-tool.cmd false
 -}
 -
 -prompt_given()
 +prompt_given ()
  {
        prompt="$1"
        test "$prompt" = "Launch 'test-tool' [Y/n]: branch"
  }
  
 -stdin_contains()
 +stdin_contains ()
  {
        grep >/dev/null "$1"
  }
  
 -stdin_doesnot_contain()
 +stdin_doesnot_contain ()
  {
        ! stdin_contains "$1"
  }
@@@ -47,237 -65,249 +47,237 @@@ test_expect_success PERL 'setup' 
  
  # Configure a custom difftool.<tool>.cmd and use it
  test_expect_success PERL 'custom commands' '
 -      restore_test_defaults &&
 -      git config difftool.test-tool.cmd "cat \$REMOTE" &&
 +      difftool_test_setup &&
 +      test_config difftool.test-tool.cmd "cat \"\$REMOTE\"" &&
 +      echo master >expect &&
 +      git difftool --no-prompt branch >actual &&
 +      test_cmp expect actual &&
  
 -      diff=$(git difftool --no-prompt branch) &&
 -      test "$diff" = "master" &&
 -
 -      restore_test_defaults &&
 -      diff=$(git difftool --no-prompt branch) &&
 -      test "$diff" = "branch"
 +      test_config difftool.test-tool.cmd "cat \"\$LOCAL\"" &&
 +      echo branch >expect &&
 +      git difftool --no-prompt branch >actual &&
 +      test_cmp expect actual
  '
  
 -# Ensures that a custom difftool.<tool>.cmd overrides built-ins
 -test_expect_success PERL 'custom commands override built-ins' '
 -      restore_test_defaults &&
 -      git config difftool.defaults.cmd "cat \$REMOTE" &&
 -
 -      diff=$(git difftool --tool defaults --no-prompt branch) &&
 -      test "$diff" = "master" &&
 -
 -      git config --unset difftool.defaults.cmd
 +test_expect_success PERL 'custom tool commands override built-ins' '
 +      test_config difftool.vimdiff.cmd "cat \"\$REMOTE\"" &&
 +      echo master >expect &&
 +      git difftool --tool vimdiff --no-prompt branch >actual &&
 +      test_cmp expect actual
  '
  
 -# Ensures that git-difftool ignores bogus --tool values
  test_expect_success PERL 'difftool ignores bad --tool values' '
 -      diff=$(git difftool --no-prompt --tool=bad-tool branch)
 -      test "$?" = 1 &&
 -      test "$diff" = ""
 +      : >expect &&
 +      test_expect_code 1 \
 +              git difftool --no-prompt --tool=bad-tool branch >actual &&
 +      test_cmp expect actual
  '
  
  test_expect_success PERL 'difftool forwards arguments to diff' '
 +      difftool_test_setup &&
        >for-diff &&
        git add for-diff &&
        echo changes>for-diff &&
        git add for-diff &&
 -      diff=$(git difftool --cached --no-prompt -- for-diff) &&
 -      test "$diff" = "" &&
 +      : >expect &&
 +      git difftool --cached --no-prompt -- for-diff >actual &&
 +      test_cmp expect actual &&
        git reset -- for-diff &&
        rm for-diff
  '
  
  test_expect_success PERL 'difftool honors --gui' '
 -      git config merge.tool bogus-tool &&
 -      git config diff.tool bogus-tool &&
 -      git config diff.guitool test-tool &&
 -
 -      diff=$(git difftool --no-prompt --gui branch) &&
 -      test "$diff" = "branch" &&
 +      difftool_test_setup &&
 +      test_config merge.tool bogus-tool &&
 +      test_config diff.tool bogus-tool &&
 +      test_config diff.guitool test-tool &&
  
 -      restore_test_defaults
 +      echo branch >expect &&
 +      git difftool --no-prompt --gui branch >actual &&
 +      test_cmp expect actual
  '
  
  test_expect_success PERL 'difftool --gui last setting wins' '
 -      git config diff.guitool bogus-tool &&
 -      git difftool --no-prompt --gui --no-gui &&
 +      difftool_test_setup &&
 +      : >expect &&
 +      git difftool --no-prompt --gui --no-gui >actual &&
 +      test_cmp expect actual &&
  
 -      git config merge.tool bogus-tool &&
 -      git config diff.tool bogus-tool &&
 -      git config diff.guitool test-tool &&
 -      diff=$(git difftool --no-prompt --no-gui --gui branch) &&
 -      test "$diff" = "branch" &&
 -
 -      restore_test_defaults
 +      test_config merge.tool bogus-tool &&
 +      test_config diff.tool bogus-tool &&
 +      test_config diff.guitool test-tool &&
 +      echo branch >expect &&
 +      git difftool --no-prompt --no-gui --gui branch >actual &&
 +      test_cmp expect actual
  '
  
  test_expect_success PERL 'difftool --gui works without configured diff.guitool' '
 -      git config diff.tool test-tool &&
 -
 -      diff=$(git difftool --no-prompt --gui branch) &&
 -      test "$diff" = "branch" &&
 -
 -      restore_test_defaults
 +      difftool_test_setup &&
 +      echo branch >expect &&
 +      git difftool --no-prompt --gui branch >actual &&
 +      test_cmp expect actual
  '
  
  # Specify the diff tool using $GIT_DIFF_TOOL
  test_expect_success PERL 'GIT_DIFF_TOOL variable' '
 -      test_might_fail git config --unset diff.tool &&
 -      GIT_DIFF_TOOL=test-tool &&
 -      export GIT_DIFF_TOOL &&
 -
 -      diff=$(git difftool --no-prompt branch) &&
 -      test "$diff" = "branch" &&
 -
 -      restore_test_defaults
 +      difftool_test_setup &&
 +      git config --unset diff.tool &&
 +      echo branch >expect &&
 +      GIT_DIFF_TOOL=test-tool git difftool --no-prompt branch >actual &&
 +      test_cmp expect actual
  '
  
  # Test the $GIT_*_TOOL variables and ensure
  # that $GIT_DIFF_TOOL always wins unless --tool is specified
  test_expect_success PERL 'GIT_DIFF_TOOL overrides' '
 -      git config diff.tool bogus-tool &&
 -      git config merge.tool bogus-tool &&
 -
 -      GIT_DIFF_TOOL=test-tool &&
 -      export GIT_DIFF_TOOL &&
 -
 -      diff=$(git difftool --no-prompt branch) &&
 -      test "$diff" = "branch" &&
 +      difftool_test_setup &&
 +      test_config diff.tool bogus-tool &&
 +      test_config merge.tool bogus-tool &&
  
 -      GIT_DIFF_TOOL=bogus-tool &&
 -      export GIT_DIFF_TOOL &&
 +      echo branch >expect &&
 +      GIT_DIFF_TOOL=test-tool git difftool --no-prompt branch >actual &&
 +      test_cmp expect actual &&
  
 -      diff=$(git difftool --no-prompt --tool=test-tool branch) &&
 -      test "$diff" = "branch" &&
 -
 -      restore_test_defaults
 +      test_config diff.tool bogus-tool &&
 +      test_config merge.tool bogus-tool &&
 +      GIT_DIFF_TOOL=bogus-tool \
 +              git difftool --no-prompt --tool=test-tool branch >actual &&
 +      test_cmp expect actual
  '
  
  # Test that we don't have to pass --no-prompt to difftool
  # when $GIT_DIFFTOOL_NO_PROMPT is true
  test_expect_success PERL 'GIT_DIFFTOOL_NO_PROMPT variable' '
 -      GIT_DIFFTOOL_NO_PROMPT=true &&
 -      export GIT_DIFFTOOL_NO_PROMPT &&
 -
 -      diff=$(git difftool branch) &&
 -      test "$diff" = "branch" &&
 -
 -      restore_test_defaults
 +      difftool_test_setup &&
 +      echo branch >expect &&
 +      GIT_DIFFTOOL_NO_PROMPT=true git difftool branch >actual &&
 +      test_cmp expect actual
  '
  
  # git-difftool supports the difftool.prompt variable.
  # Test that GIT_DIFFTOOL_PROMPT can override difftool.prompt = false
  test_expect_success PERL 'GIT_DIFFTOOL_PROMPT variable' '
 -      git config difftool.prompt false &&
 -      GIT_DIFFTOOL_PROMPT=true &&
 -      export GIT_DIFFTOOL_PROMPT &&
 -
 -      prompt=$(echo | git difftool branch | tail -1) &&
 -      prompt_given "$prompt" &&
 -
 -      restore_test_defaults
 +      difftool_test_setup &&
 +      test_config difftool.prompt false &&
 +      echo >input &&
 +      GIT_DIFFTOOL_PROMPT=true git difftool branch <input >output &&
 +      prompt=$(tail -1 <output) &&
 +      prompt_given "$prompt"
  '
  
  # Test that we don't have to pass --no-prompt when difftool.prompt is false
  test_expect_success PERL 'difftool.prompt config variable is false' '
 -      git config difftool.prompt false &&
 -
 -      diff=$(git difftool branch) &&
 -      test "$diff" = "branch" &&
 -
 -      restore_test_defaults
 +      difftool_test_setup &&
 +      test_config difftool.prompt false &&
 +      echo branch >expect &&
 +      git difftool branch >actual &&
 +      test_cmp expect actual
  '
  
  # Test that we don't have to pass --no-prompt when mergetool.prompt is false
  test_expect_success PERL 'difftool merge.prompt = false' '
 +      difftool_test_setup &&
        test_might_fail git config --unset difftool.prompt &&
 -      git config mergetool.prompt false &&
 -
 -      diff=$(git difftool branch) &&
 -      test "$diff" = "branch" &&
 -
 -      restore_test_defaults
 +      test_config mergetool.prompt false &&
 +      echo branch >expect &&
 +      git difftool branch >actual &&
 +      test_cmp expect actual
  '
  
  # Test that the -y flag can override difftool.prompt = true
  test_expect_success PERL 'difftool.prompt can overridden with -y' '
 -      git config difftool.prompt true &&
 -
 -      diff=$(git difftool -y branch) &&
 -      test "$diff" = "branch" &&
 -
 -      restore_test_defaults
 +      difftool_test_setup &&
 +      test_config difftool.prompt true &&
 +      echo branch >expect &&
 +      git difftool -y branch >actual &&
 +      test_cmp expect actual
  '
  
  # Test that the --prompt flag can override difftool.prompt = false
  test_expect_success PERL 'difftool.prompt can overridden with --prompt' '
 -      git config difftool.prompt false &&
 -
 -      prompt=$(echo | git difftool --prompt branch | tail -1) &&
 -      prompt_given "$prompt" &&
 -
 -      restore_test_defaults
 +      difftool_test_setup &&
 +      test_config difftool.prompt false &&
 +      echo >input &&
 +      git difftool --prompt branch <input >output &&
 +      prompt=$(tail -1 <output) &&
 +      prompt_given "$prompt"
  '
  
  # Test that the last flag passed on the command-line wins
  test_expect_success PERL 'difftool last flag wins' '
 -      diff=$(git difftool --prompt --no-prompt branch) &&
 -      test "$diff" = "branch" &&
 -
 -      restore_test_defaults &&
 -
 -      prompt=$(echo | git difftool --no-prompt --prompt branch | tail -1) &&
 -      prompt_given "$prompt" &&
 -
 -      restore_test_defaults
 +      difftool_test_setup &&
 +      echo branch >expect &&
 +      git difftool --prompt --no-prompt branch >actual &&
 +      test_cmp expect actual &&
 +      echo >input &&
 +      git difftool --no-prompt --prompt branch <input >output &&
 +      prompt=$(tail -1 <output) &&
 +      prompt_given "$prompt"
  '
  
  # git-difftool falls back to git-mergetool config variables
  # so test that behavior here
  test_expect_success PERL 'difftool + mergetool config variables' '
 -      remove_config_vars &&
 -      git config merge.tool test-tool &&
 -      git config mergetool.test-tool.cmd "cat \$LOCAL" &&
 -
 -      diff=$(git difftool --no-prompt branch) &&
 -      test "$diff" = "branch" &&
 +      test_config merge.tool test-tool &&
 +      test_config mergetool.test-tool.cmd "cat \$LOCAL" &&
 +      echo branch >expect &&
 +      git difftool --no-prompt branch >actual &&
 +      test_cmp expect actual &&
  
        # set merge.tool to something bogus, diff.tool to test-tool
 -      git config merge.tool bogus-tool &&
 -      git config diff.tool test-tool &&
 -
 -      diff=$(git difftool --no-prompt branch) &&
 -      test "$diff" = "branch" &&
 -
 -      restore_test_defaults
 +      test_config merge.tool bogus-tool &&
 +      test_config diff.tool test-tool &&
 +      git difftool --no-prompt branch >actual &&
 +      test_cmp expect actual
  '
  
  test_expect_success PERL 'difftool.<tool>.path' '
 -      git config difftool.tkdiff.path echo &&
 -      diff=$(git difftool --tool=tkdiff --no-prompt branch) &&
 -      git config --unset difftool.tkdiff.path &&
 -      lines=$(echo "$diff" | grep file | wc -l) &&
 -      test "$lines" -eq 1 &&
 -
 -      restore_test_defaults
 +      test_config difftool.tkdiff.path echo &&
 +      git difftool --tool=tkdiff --no-prompt branch >output &&
 +      lines=$(grep file output | wc -l) &&
 +      test "$lines" -eq 1
  '
  
  test_expect_success PERL 'difftool --extcmd=cat' '
 -      diff=$(git difftool --no-prompt --extcmd=cat branch) &&
 -      test "$diff" = branch"$LF"master
 +      echo branch >expect &&
 +      echo master >>expect &&
 +      git difftool --no-prompt --extcmd=cat branch >actual &&
 +      test_cmp expect actual
  '
  
  test_expect_success PERL 'difftool --extcmd cat' '
 -      diff=$(git difftool --no-prompt --extcmd cat branch) &&
 -      test "$diff" = branch"$LF"master
 +      echo branch >expect &&
 +      echo master >>expect &&
 +      git difftool --no-prompt --extcmd=cat branch >actual &&
 +      test_cmp expect actual
  '
  
  test_expect_success PERL 'difftool -x cat' '
 -      diff=$(git difftool --no-prompt -x cat branch) &&
 -      test "$diff" = branch"$LF"master
 +      echo branch >expect &&
 +      echo master >>expect &&
 +      git difftool --no-prompt -x cat branch >actual &&
 +      test_cmp expect actual
  '
  
  test_expect_success PERL 'difftool --extcmd echo arg1' '
 -      diff=$(git difftool --no-prompt --extcmd sh\ -c\ \"echo\ \$1\" branch) &&
 -      test "$diff" = file
 +      echo file >expect &&
 +      git difftool --no-prompt \
 +              --extcmd sh\ -c\ \"echo\ \$1\" branch >actual &&
 +      test_cmp expect actual
  '
  
  test_expect_success PERL 'difftool --extcmd cat arg1' '
 -      diff=$(git difftool --no-prompt --extcmd sh\ -c\ \"cat\ \$1\" branch) &&
 -      test "$diff" = master
 +      echo master >expect &&
 +      git difftool --no-prompt \
 +              --extcmd sh\ -c\ \"cat\ \$1\" branch >actual &&
 +      test_cmp expect actual
  '
  
  test_expect_success PERL 'difftool --extcmd cat arg2' '
 -      diff=$(git difftool --no-prompt --extcmd sh\ -c\ \"cat\ \$2\" branch) &&
 -      test "$diff" = branch
 +      echo branch >expect &&
 +      git difftool --no-prompt \
 +              --extcmd sh\ -c\ \"cat\ \$2\" branch >actual &&
 +      test_cmp expect actual
  '
  
  # Create a second file on master and a different version on branch
@@@ -294,26 -324,26 +294,26 @@@ test_expect_success PERL 'setup with 2 
  '
  
  test_expect_success PERL 'say no to the first file' '
 -      diff=$( (echo n; echo) | git difftool -x cat branch ) &&
 -
 -      echo "$diff" | stdin_contains m2 &&
 -      echo "$diff" | stdin_contains br2 &&
 -      echo "$diff" | stdin_doesnot_contain master &&
 -      echo "$diff" | stdin_doesnot_contain branch
 +      (echo n && echo) >input &&
 +      git difftool -x cat branch <input >output &&
 +      stdin_contains m2 <output &&
 +      stdin_contains br2 <output &&
 +      stdin_doesnot_contain master <output &&
 +      stdin_doesnot_contain branch <output
  '
  
  test_expect_success PERL 'say no to the second file' '
 -      diff=$( (echo; echo n) | git difftool -x cat branch ) &&
 -
 -      echo "$diff" | stdin_contains master &&
 -      echo "$diff" | stdin_contains branch &&
 -      echo "$diff" | stdin_doesnot_contain m2 &&
 -      echo "$diff" | stdin_doesnot_contain br2
 +      (echo && echo n) >input &&
 +      git difftool -x cat branch <input >output &&
 +      stdin_contains master <output &&
 +      stdin_contains branch  <output &&
 +      stdin_doesnot_contain m2 <output &&
 +      stdin_doesnot_contain br2 <output
  '
  
  test_expect_success PERL 'difftool --tool-help' '
 -      tool_help=$(git difftool --tool-help) &&
 -      echo "$tool_help" | stdin_contains tool
 +      git difftool --tool-help >output &&
 +      stdin_contains tool <output
  '
  
  test_expect_success PERL 'setup change in subdirectory' '
@@@ -329,29 -359,51 +329,51 @@@
  '
  
  test_expect_success PERL 'difftool -d' '
 -      diff=$(git difftool -d --extcmd ls branch) &&
 -      echo "$diff" | stdin_contains sub &&
 -      echo "$diff" | stdin_contains file
 +      git difftool -d --extcmd ls branch >output &&
 +      stdin_contains sub <output &&
 +      stdin_contains file <output
  '
  
  test_expect_success PERL 'difftool --dir-diff' '
 -      diff=$(git difftool --dir-diff --extcmd ls branch) &&
 -      echo "$diff" | stdin_contains sub &&
 -      echo "$diff" | stdin_contains file
 +      git difftool --dir-diff --extcmd ls branch >output &&
 +      stdin_contains sub <output &&
 +      stdin_contains file <output
  '
  
+ write_script .git/CHECK_SYMLINKS <<\EOF
+ for f in file file2 sub/sub
+ do
+       echo "$f"
+       readlink "$2/$f"
+ done >actual
+ EOF
+ 
+ test_expect_success PERL,SYMLINKS 'difftool --dir-diff --symlink without unstaged changes' '
+       cat >expect <<-EOF &&
+       file
+       $(pwd)/file
+       file2
+       $(pwd)/file2
+       sub/sub
+       $(pwd)/sub/sub
+       EOF
+       git difftool --dir-diff --symlink \
+               --extcmd "./.git/CHECK_SYMLINKS" branch HEAD &&
+       test_cmp actual expect
+ '
+ 
  test_expect_success PERL 'difftool --dir-diff ignores --prompt' '
 -      diff=$(git difftool --dir-diff --prompt --extcmd ls branch) &&
 -      echo "$diff" | stdin_contains sub &&
 -      echo "$diff" | stdin_contains file
 +      git difftool --dir-diff --prompt --extcmd ls branch >output &&
 +      stdin_contains sub <output &&
 +      stdin_contains file <output
  '
  
  test_expect_success PERL 'difftool --dir-diff from subdirectory' '
        (
                cd sub &&
 -              diff=$(git difftool --dir-diff --extcmd ls branch) &&
 -              echo "$diff" | stdin_contains sub &&
 -              echo "$diff" | stdin_contains file
 +              git difftool --dir-diff --extcmd ls branch >output &&
 +              stdin_contains sub <output &&
 +              stdin_contains file <output
        )
  '