difftool: Eliminate global variables

Organize the script so that it has a single main() function which
calls out to dir_diff() and file_diff() functions. This eliminates
"dir-diff"-specific variables that do not need to be calculated when
performing a regular file-diff.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-difftool.perl b/git-difftool.perl
index ac0ed633bd1328ed6f09095c28b524f7897aa674..41ba9323f8356cf7e9b3df97d24e76d0da89e7e6 100755 (executable)
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -22,11 +22,6 @@ use File::Temp qw(tempdir);
 use Getopt::Long qw(:config pass_through);
 use Git;
 
-my @working_tree;
-my $rc;
-my $repo = Git->repository();
-my $repo_path = $repo->repo_path();
-
 sub usage
 {
        my $exitcode = shift;
@@ -43,6 +38,8 @@ USAGE
 
 sub find_worktree
 {
+       my ($repo) = @_;
+
        # Git->repository->wc_path() does not honor changes to the working
        # tree location made by $ENV{GIT_WORK_TREE} or the 'core.worktree'
        # config variable.
@@ -61,8 +58,6 @@ sub find_worktree
        return $worktree;
 }
 
-my $workdir = find_worktree();
-
 sub print_tool_help
 {
        my ($cmd, @found, @notfound);
@@ -97,10 +92,13 @@ sub print_tool_help
 
 sub setup_dir_diff
 {
+       my ($repo, $workdir) = @_;
+
        # Run the diff; exit immediately if no diff found
        # 'Repository' and 'WorkingCopy' must be explicitly set to insure that
        # if $GIT_DIR and $GIT_WORK_TREE are set in ENV, they are actually used
        # by Git->repository->command*.
+       my $repo_path = $repo->repo_path();
        my $diffrepo = Git->repository(Repository => $repo_path, WorkingCopy => $workdir);
        my $diffrtn = $diffrepo->command_oneline('diff', '--raw', '--no-abbrev', '-z', @ARGV);
        exit(0) if (length($diffrtn) == 0);
@@ -121,6 +119,7 @@ sub setup_dir_diff
        my $rindex = '';
        my %submodule;
        my %symlink;
+       my @working_tree = ();
        my @rawdiff = split('\0', $diffrtn);
 
        my $i = 0;
@@ -188,7 +187,7 @@ sub setup_dir_diff
        ($inpipe, $ctx) = $repo->command_input_pipe(qw/update-index -z --index-info/);
        print($inpipe $lindex);
        $repo->command_close_pipe($inpipe, $ctx);
-       $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
+       my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
        exit($rc | ($rc >> 8)) if ($rc != 0);
 
        $ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
@@ -238,7 +237,7 @@ sub setup_dir_diff
                }
        }
 
-       return ($ldir, $rdir);
+       return ($ldir, $rdir, @working_tree);
 }
 
 sub write_to_file
@@ -261,54 +260,70 @@ sub write_to_file
        close($fh);
 }
 
-# parse command-line options. all unrecognized options and arguments
-# are passed through to the 'git diff' command.
-my ($difftool_cmd, $dirdiff, $extcmd, $gui, $help, $prompt, $tool_help);
-GetOptions('g|gui!' => \$gui,
-       'd|dir-diff' => \$dirdiff,
-       'h' => \$help,
-       'prompt!' => \$prompt,
-       'y' => sub { $prompt = 0; },
-       't|tool:s' => \$difftool_cmd,
-       'tool-help' => \$tool_help,
-       'x|extcmd:s' => \$extcmd);
-
-if (defined($help)) {
-       usage(0);
-}
-if (defined($tool_help)) {
-       print_tool_help();
-}
-if (defined($difftool_cmd)) {
-       if (length($difftool_cmd) > 0) {
-               $ENV{GIT_DIFF_TOOL} = $difftool_cmd;
-       } else {
-               print "No <tool> given for --tool=<tool>\n";
-               usage(1);
+sub main
+{
+       # parse command-line options. all unrecognized options and arguments
+       # are passed through to the 'git diff' command.
+       my ($difftool_cmd, $dirdiff, $extcmd, $gui, $help, $prompt, $tool_help);
+       GetOptions('g|gui!' => \$gui,
+               'd|dir-diff' => \$dirdiff,
+               'h' => \$help,
+               'prompt!' => \$prompt,
+               'y' => sub { $prompt = 0; },
+               't|tool:s' => \$difftool_cmd,
+               'tool-help' => \$tool_help,
+               'x|extcmd:s' => \$extcmd);
+
+       if (defined($help)) {
+               usage(0);
        }
-}
-if (defined($extcmd)) {
-       if (length($extcmd) > 0) {
-               $ENV{GIT_DIFFTOOL_EXTCMD} = $extcmd;
-       } else {
-               print "No <cmd> given for --extcmd=<cmd>\n";
-               usage(1);
+       if (defined($tool_help)) {
+               print_tool_help();
        }
-}
-if ($gui) {
-       my $guitool = '';
-       $guitool = Git::config('diff.guitool');
-       if (length($guitool) > 0) {
-               $ENV{GIT_DIFF_TOOL} = $guitool;
+       if (defined($difftool_cmd)) {
+               if (length($difftool_cmd) > 0) {
+                       $ENV{GIT_DIFF_TOOL} = $difftool_cmd;
+               } else {
+                       print "No <tool> given for --tool=<tool>\n";
+                       usage(1);
+               }
+       }
+       if (defined($extcmd)) {
+               if (length($extcmd) > 0) {
+                       $ENV{GIT_DIFFTOOL_EXTCMD} = $extcmd;
+               } else {
+                       print "No <cmd> given for --extcmd=<cmd>\n";
+                       usage(1);
+               }
+       }
+       if ($gui) {
+               my $guitool = '';
+               $guitool = Git::config('diff.guitool');
+               if (length($guitool) > 0) {
+                       $ENV{GIT_DIFF_TOOL} = $guitool;
+               }
+       }
+
+       # In directory diff mode, 'git-difftool--helper' is called once
+       # to compare the a/b directories.  In file diff mode, 'git diff'
+       # will invoke a separate instance of 'git-difftool--helper' for
+       # each file that changed.
+       if (defined($dirdiff)) {
+               dir_diff($extcmd);
+       } else {
+               file_diff($prompt);
        }
 }
 
-# In directory diff mode, 'git-difftool--helper' is called once
-# to compare the a/b directories.  In file diff mode, 'git diff'
-# will invoke a separate instance of 'git-difftool--helper' for
-# each file that changed.
-if (defined($dirdiff)) {
-       my ($a, $b) = setup_dir_diff();
+sub dir_diff
+{
+       my ($extcmd) = @_;
+
+       my $rc;
+       my $repo = Git->repository();
+
+       my $workdir = find_worktree($repo);
+       my ($a, $b, @working_tree) = setup_dir_diff($repo, $workdir);
        if (defined($extcmd)) {
                $rc = system($extcmd, $a, $b);
        } else {
@@ -327,7 +342,12 @@ if (defined($dirdiff)) {
                        chmod(stat("$b/$file")->mode, "$workdir/$file") or die $!;
                }
        }
-} else {
+}
+
+sub file_diff
+{
+       my ($prompt) = @_;
+
        if (defined($prompt)) {
                if ($prompt) {
                        $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
@@ -347,3 +367,5 @@ if (defined($dirdiff)) {
        my $rc = system('git', 'diff', @ARGV);
        exit($rc | ($rc >> 8));
 }
+
+main();