WebKitTools/Scripts/svn-apply - WebKit - Git at Google

 #!/usr/bin/perl -w

 # Copyright (C) 2005, 2006, 2007 Apple Inc.  All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 #
 # 1.  Redistributions of source code must retain the above copyright
 #     notice, this list of conditions and the following disclaimer.
 # 2.  Redistributions in binary form must reproduce the above copyright
 #     notice, this list of conditions and the following disclaimer in the
 #     documentation and/or other materials provided with the distribution.
 # 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 #     its contributors may be used to endorse or promote products derived
 #     from this software without specific prior written permission.
 #
 # THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 # EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 # DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 # DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 # (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 # ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 # THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 # "patch" script for WebKit Open Source Project, used to apply patches.

 # Differences from invoking "patch -p0":
 #
 #   Handles added files (does a svn add with logic to handle local changes).
 #   Handles added directories (does a svn add).
 #   Handles removed files (does a svn rm with logic to handle local changes).
 #   Handles removed directories--those with no more files or directories left in them
 #       (does a svn rm).
 #   Has mode where it will roll back to svn version numbers in the patch file so svn
 #       can do a 3-way merge.
 #   Paths from Index: lines are used rather than the paths on the patch lines, which
 #       makes patches generated by "cvs diff" work (increasingly unimportant since we
 #       use Subversion now).
 #   ChangeLog patches use --fuzz=3 to prevent rejects, and the entry date is set in
 #       the patch to today's date using $changeLogTimeZone.
 #   Handles binary files (requires patches made by svn-create-patch).
 #   Handles copied and moved files (requires patches made by svn-create-patch).
 #   Handles git-diff patches (without binary changes) created at the top-level directory
 #
 # Missing features:
 #
 #   Handle property changes.
 #   Handle copied and moved directories (would require patches made by svn-create-patch).
 #   When doing a removal, check that old file matches what's being removed.
 #   Notice a patch that's being applied at the "wrong level" and make it work anyway.
 #   Do a dry run on the whole patch and don't do anything if part of the patch is
 #       going to fail (probably too strict unless we exclude ChangeLog).
 #   Handle git-diff patches with binary changes

 use strict;
 use warnings;

 use Cwd;
 use Digest::MD5;
 use File::Basename;
 use File::Spec;
 use Getopt::Long;
 use MIME::Base64;
 use POSIX qw(strftime);

 sub addDirectoriesIfNeeded($);
 sub applyPatch($$;$);
 sub checksum($);
 sub fixChangeLogPatch($);
 sub gitdiff2svndiff($);
 sub handleBinaryChange($$);
 sub isDirectoryEmptyForRemoval($);
 sub patch($);
 sub removeDirectoriesIfNeeded();
 sub setChangeLogDate($);
 sub svnStatus($);

 # Project time zone for Cupertino, CA, US
 my $changeLogTimeZone = "PST8PDT";

 my $merge = 0;
 my $showHelp = 0;
 if (!GetOptions("merge!" => \$merge, "help!" => \$showHelp) || $showHelp) {
     print STDERR basename($0) . " [-h|--help] [-m|--merge] patch1 [patch2 ...]\n";
     exit 1;
 }

 my %removeDirectoryIgnoreList = (
     '.' => 1,
     '..' => 1,
     '.svn' => 1,
     '_svn' => 1,
 );

 my %checkedDirectories;
 my %copiedFiles;
 my @patches;
 my %versions;

 my $copiedFromPath;
 my $filter;
 my $indexPath;
 my $patch;
 while (<>) {
     s/\r//g;
     chomp;
     if (!defined($indexPath) && m#^diff --git a/#) {
         $filter = \&gitdiff2svndiff;
     }
     $_ = &$filter($_) if $filter;
     if (/^Index: (.+)/) {
         $indexPath = $1;
         if ($patch) {
             if (!$copiedFromPath) {
                 push @patches, $patch;
             }
             $copiedFromPath = "";
             $patch = "";
         }
     }
     if ($indexPath) {
         # Fix paths on diff, ---, and +++ lines to match preceding Index: line.
         s/\S+$/$indexPath/ if /^diff/;
         s/^--- \S+/--- $indexPath/;
         if (/^--- .+\(from (\S+):(\d+)\)$/) {
             $copiedFromPath = $1;
             $copiedFiles{$indexPath} = $copiedFromPath;
             $versions{$copiedFromPath} = $2 if ($2 != 0);
         }
         elsif (/^--- .+\(revision (\d+)\)$/) {
             $versions{$indexPath} = $1 if ($1 != 0);
         }
         if (s/^\+\+\+ \S+/+++ $indexPath/) {
             $indexPath = "";
         }
     }
     $patch .= $_;
     $patch .= "\n";
 }

 if ($patch && !$copiedFromPath) {
     push @patches, $patch;
 }

 if ($merge) {
     for my $file (sort keys %versions) {
         print "Getting version $versions{$file} of $file\n";
         system "svn", "update", "-r", $versions{$file}, $file;
     }
 }

 # Handle copied and moved files first since moved files may have their source deleted before the move.
 for my $file (keys %copiedFiles) {
     addDirectoriesIfNeeded(dirname($file));
     system "svn", "copy", $copiedFiles{$file}, $file;
 }

 for $patch (@patches) {
     patch($patch);
 }

 removeDirectoriesIfNeeded();

 exit 0;

 sub addDirectoriesIfNeeded($)
 {
     my ($path) = @_;
     my @dirs = File::Spec->splitdir($path);
     my $dir = ".";
     while (scalar @dirs) {
         $dir = File::Spec->catdir($dir, shift @dirs);
         next if exists $checkedDirectories{$dir};
         if (! -e $dir) {
             mkdir $dir or die "Failed to create required directory '$dir' for path '$path'\n";
             system "svn", "add", $dir;
             $checkedDirectories{$dir} = 1;
         }
         elsif (-d $dir) {
             my $svnOutput = svnStatus($dir);
             if ($svnOutput && $svnOutput =~ m#\?\s+$dir\n#) {
                 system "svn", "add", $dir;
             }
             $checkedDirectories{$dir} = 1;
         }
         else {
             die "'$dir' is not a directory";
         }
     }
 }

 sub applyPatch($$;$)
 {
     my ($patch, $fullPath, $options) = @_;
     $options = [] if (! $options);
     my $command = "patch " . join(" ", "-p0", @{$options});
     open PATCH, "| $command" or die "Failed to patch $fullPath\n";
     print PATCH $patch;
     close PATCH;
 }

 sub checksum($)
 {
     my $file = shift;
     open(FILE, $file) or die "Can't open '$file': $!";
     binmode(FILE);
     my $checksum = Digest::MD5->new->addfile(*FILE)->hexdigest();
     close(FILE);
     return $checksum;
 }

 sub fixChangeLogPatch($)
 {
     my $patch = shift;
     my $contextLineCount = 3;

     return $patch if $patch !~ /\n@@ -1,(\d+) \+1,(\d+) @@\n( .*\n)+(\+.*\n)+( .*\n){$contextLineCount}$/m;
     my ($oldLineCount, $newLineCount) = ($1, $2);
     return $patch if $oldLineCount <= $contextLineCount;

     # The diff(1) command is greedy when matching lines, so a new ChangeLog entry will
     # have lines of context at the top of a patch when the existing entry has the same
     # date and author as the new entry.  This nifty loop alters a ChangeLog patch so
     # that the added lines ("+") in the patch always start at the beginning of the
     # patch and there are no initial lines of context.
     my $newPatch;
     my $lineCountInState = 0;
     my $oldContentLineCountReduction = $oldLineCount - $contextLineCount;
     my $newContentLineCountWithoutContext = $newLineCount - $oldLineCount - $oldContentLineCountReduction;
     my ($stateHeader, $statePreContext, $stateNewChanges, $statePostContext) = (1..4);
     my $state = $stateHeader;
     foreach my $line (split(/\n/, $patch)) {
         $lineCountInState++;
         if ($state == $stateHeader && $line =~ /^@@ -1,$oldLineCount \+1,$newLineCount @\@$/) {
             $line = "@@ -1,$contextLineCount +1," . ($newLineCount - $oldContentLineCountReduction) . " @@";
             $lineCountInState = 0;
             $state = $statePreContext;
         } elsif ($state == $statePreContext && substr($line, 0, 1) eq " ") {
             $line = "+" . substr($line, 1);
             if ($lineCountInState == $oldContentLineCountReduction) {
                 $lineCountInState = 0;
                 $state = $stateNewChanges;
             }
         } elsif ($state == $stateNewChanges && substr($line, 0, 1) eq "+") {
             # No changes to these lines
             if ($lineCountInState == $newContentLineCountWithoutContext) {
                 $lineCountInState = 0;
                 $state = $statePostContext;
             }
         } elsif ($state == $statePostContext) {
             if (substr($line, 0, 1) eq "+" && $lineCountInState <= $oldContentLineCountReduction) {
                 $line = " " . substr($line, 1);
             } elsif ($lineCountInState > $contextLineCount && substr($line, 0, 1) eq " ") {
                 next; # Discard
             }
         }
         $newPatch .= $line . "\n";
     }

     return $newPatch;
 }

 sub gitdiff2svndiff($)
 {
     $_ = shift @_;
     if (m#^diff --git a/(.+) b/(.+)#) {
         return "Index: $1";
     } elsif (m/^new file.*/) {
         return "";
     } elsif (m#^index [0-9a-f]{7}\.\.[0-9a-f]{7} [0-9]{6}#) {
         return "===================================================================";
     } elsif (m#^--- a/(.+)#) {
         return "--- $1";
     } elsif (m#^\+\+\+ b/(.+)#) {
         return "+++ $1";
     }
     return $_;
 }

 sub handleBinaryChange($$)
 {
     my ($fullPath, $contents) = @_;
     if ($contents =~ m#((\n[A-Za-z0-9+/]{76})+\n[A-Za-z0-9+/=]{4,76}\n)#) {
         # Addition or Modification
         open FILE, ">", $fullPath or die;
         print FILE decode_base64($1);
         close FILE;
         my $svnOutput = svnStatus($fullPath);
         if ($svnOutput && substr($svnOutput, 0, 1) eq "?") {
             # Addition
             system "svn", "add", $fullPath;
         } else {
             # Modification
             print $svnOutput if $svnOutput;
         }
     } else {
         # Deletion
         system "svn", "rm", $fullPath;
     }
 }

 sub isDirectoryEmptyForRemoval($)
 {
     my ($dir) = @_;
     my $directoryIsEmpty = 1;
     opendir DIR, $dir or die "Could not open '$dir' to list files: $?";
     for (my $item = readdir DIR; $item && $directoryIsEmpty; $item = readdir DIR) {
         next if exists $removeDirectoryIgnoreList{$item};
         if (! -d File::Spec->catdir($dir, $item)) {
             $directoryIsEmpty = 0;
         } else {
             my $svnOutput = svnStatus(File::Spec->catdir($dir, $item));
             next if $svnOutput && substr($svnOutput, 0, 1) eq "D";
             $directoryIsEmpty = 0;
         }
     }
     closedir DIR;
     return $directoryIsEmpty;
 }

 sub patch($)
 {
     my ($patch) = @_;
     return if !$patch;

     unless ($patch =~ m|^Index: ([^\n]+)|) {
         my $separator = '-' x 67;
         warn "Failed to find 'Index:' in:\n$separator\n$patch\n$separator\n";
         return;
     }
     my $fullPath = $1;

     my $deletion = 0;
     my $addition = 0;
     my $isBinary = 0;

     $addition = 1 if $patch =~ /\n--- .+\(revision 0\)\n/;
     $deletion = 1 if $patch =~ /\n@@ .* \+0,0 @@/;
     $isBinary = 1 if $patch =~ /\nCannot display: file marked as a binary type\./;

     if (!$addition && !$deletion && !$isBinary) {
         # Standard patch, patch tool can handle this.
         if (basename($fullPath) eq "ChangeLog") {
             my $changeLogDotOrigExisted = -f "${fullPath}.orig";
             applyPatch(setChangeLogDate(fixChangeLogPatch($patch)), $fullPath, ["--fuzz=3"]);
             unlink("${fullPath}.orig") if (! $changeLogDotOrigExisted);
         } else {
             applyPatch($patch, $fullPath);
         }
     } else {
         # Either a deletion, an addition or a binary change.

         addDirectoriesIfNeeded(dirname($fullPath));

         if ($isBinary) {
             # Binary change
             handleBinaryChange($fullPath, $patch);
         } elsif ($deletion) {
             # Deletion
             applyPatch($patch, $fullPath, ["--force"]);
             system "svn", "rm", "--force", $fullPath;
         } else {
             # Addition
             rename($fullPath, "$fullPath.orig") if -e $fullPath;
             applyPatch($patch, $fullPath);
             unlink("$fullPath.orig") if -e "$fullPath.orig" && checksum($fullPath) eq checksum("$fullPath.orig");
             system "svn", "add", $fullPath;
             system "svn", "stat", "$fullPath.orig" if -e "$fullPath.orig";
         }
     }
 }

 sub removeDirectoriesIfNeeded()
 {
     foreach my $dir (reverse sort keys %checkedDirectories) {
         if (isDirectoryEmptyForRemoval($dir)) {
             my $svnOutput;
             open SVN, "svn rm '$dir' |" or die;
             # Only save the last line since Subversion lists all changed statuses below $dir
             while (<SVN>) {
                 $svnOutput = $_;
             }
             close SVN;
             print $svnOutput if $svnOutput;
         }
     }
 }

 sub setChangeLogDate($)
 {
     my $patch = shift;
     my $savedTimeZone = $ENV{'TZ'};
     # Set TZ temporarily so that localtime() is in that time zone
     $ENV{'TZ'} = $changeLogTimeZone;
     my $newDate = strftime("%Y-%m-%d", localtime());
     if (defined $savedTimeZone) {
          $ENV{'TZ'} = $savedTimeZone;
     } else {
          delete $ENV{'TZ'};
     }
     $patch =~ s/(\n\+)\d{4}-[^-]{2}-[^-]{2}(  )/$1$newDate$2/;
     return $patch;
 }

 sub svnStatus($)
 {
     my ($fullPath) = @_;
     my $svnStatus;
     open SVN, "svn status --non-interactive --non-recursive '$fullPath' |" or die;
     if (-d $fullPath) {
         # When running "svn stat" on a directory, we can't assume that only one
         # status will be returned (since any files with a status below the
         # directory will be returned), and we can't assume that the directory will
         # be first (since any files with unknown status will be listed first).
         my $normalizedFullPath = File::Spec->catdir(File::Spec->splitdir($fullPath));
         while (<SVN>) {
             chomp;
             my $normalizedStatPath = File::Spec->catdir(File::Spec->splitdir(substr($_, 7)));
             if ($normalizedFullPath eq $normalizedStatPath) {
                 $svnStatus = $_;
                 last;
             }
         }
         # Read the rest of the svn command output to avoid a broken pipe warning.
         local $/ = undef;
         <SVN>;
     }
     else {
         # Files will have only one status returned.
         $svnStatus = <SVN>;
     }
     close SVN;
     return $svnStatus;
 }
	#!/usr/bin/perl -w

	# Copyright (C) 2005, 2006, 2007 Apple Inc. All rights reserved.
	#
	# Redistribution and use in source and binary forms, with or without
	# modification, are permitted provided that the following conditions
	# are met:
	#
	# 1. Redistributions of source code must retain the above copyright
	# notice, this list of conditions and the following disclaimer.
	# 2. Redistributions in binary form must reproduce the above copyright
	# notice, this list of conditions and the following disclaimer in the
	# documentation and/or other materials provided with the distribution.
	# 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
	# its contributors may be used to endorse or promote products derived
	# from this software without specific prior written permission.
	#
	# THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
	# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	# DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
	# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	# "patch" script for WebKit Open Source Project, used to apply patches.

	# Differences from invoking "patch -p0":
	#
	# Handles added files (does a svn add with logic to handle local changes).
	# Handles added directories (does a svn add).
	# Handles removed files (does a svn rm with logic to handle local changes).
	# Handles removed directories--those with no more files or directories left in them
	# (does a svn rm).
	# Has mode where it will roll back to svn version numbers in the patch file so svn
	# can do a 3-way merge.
	# Paths from Index: lines are used rather than the paths on the patch lines, which
	# makes patches generated by "cvs diff" work (increasingly unimportant since we
	# use Subversion now).
	# ChangeLog patches use --fuzz=3 to prevent rejects, and the entry date is set in
	# the patch to today's date using $changeLogTimeZone.
	# Handles binary files (requires patches made by svn-create-patch).
	# Handles copied and moved files (requires patches made by svn-create-patch).
	# Handles git-diff patches (without binary changes) created at the top-level directory
	#
	# Missing features:
	#
	# Handle property changes.
	# Handle copied and moved directories (would require patches made by svn-create-patch).
	# When doing a removal, check that old file matches what's being removed.
	# Notice a patch that's being applied at the "wrong level" and make it work anyway.
	# Do a dry run on the whole patch and don't do anything if part of the patch is
	# going to fail (probably too strict unless we exclude ChangeLog).
	# Handle git-diff patches with binary changes

	use strict;
	use warnings;

	use Cwd;
	use Digest::MD5;
	use File::Basename;
	use File::Spec;
	use Getopt::Long;
	use MIME::Base64;
	use POSIX qw(strftime);

	sub addDirectoriesIfNeeded($);
	sub applyPatch($$;$);
	sub checksum($);
	sub fixChangeLogPatch($);
	sub gitdiff2svndiff($);
	sub handleBinaryChange($$);
	sub isDirectoryEmptyForRemoval($);
	sub patch($);
	sub removeDirectoriesIfNeeded();
	sub setChangeLogDate($);
	sub svnStatus($);

	# Project time zone for Cupertino, CA, US
	my $changeLogTimeZone = "PST8PDT";

	my $merge = 0;
	my $showHelp = 0;
	if (!GetOptions("merge!" => \$merge, "help!" => \$showHelp) \|\| $showHelp) {
	print STDERR basename($0) . " [-h\|--help] [-m\|--merge] patch1 [patch2 ...]\n";
	exit 1;
	}

	my %removeDirectoryIgnoreList = (
	'.' => 1,
	'..' => 1,
	'.svn' => 1,
	'_svn' => 1,
	);

	my %checkedDirectories;
	my %copiedFiles;
	my @patches;
	my %versions;

	my $copiedFromPath;
	my $filter;
	my $indexPath;
	my $patch;
	while (<>) {
	s/\r//g;
	chomp;
	if (!defined($indexPath) && m#^diff --git a/#) {
	$filter = \&gitdiff2svndiff;
	}
	$_ = &$filter($_) if $filter;
	if (/^Index: (.+)/) {
	$indexPath = $1;
	if ($patch) {
	if (!$copiedFromPath) {
	push @patches, $patch;
	}
	$copiedFromPath = "";
	$patch = "";
	}
	}
	if ($indexPath) {
	# Fix paths on diff, ---, and +++ lines to match preceding Index: line.
	s/\S+$/$indexPath/ if /^diff/;
	s/^--- \S+/--- $indexPath/;
	if (/^--- .+\(from (\S+):(\d+)\)$/) {
	$copiedFromPath = $1;
	$copiedFiles{$indexPath} = $copiedFromPath;
	$versions{$copiedFromPath} = $2 if ($2 != 0);
	}
	elsif (/^--- .+\(revision (\d+)\)$/) {
	$versions{$indexPath} = $1 if ($1 != 0);
	}
	if (s/^\+\+\+ \S+/+++ $indexPath/) {
	$indexPath = "";
	}
	}
	$patch .= $_;
	$patch .= "\n";
	}

	if ($patch && !$copiedFromPath) {
	push @patches, $patch;
	}

	if ($merge) {
	for my $file (sort keys %versions) {
	print "Getting version $versions{$file} of $file\n";
	system "svn", "update", "-r", $versions{$file}, $file;
	}
	}

	# Handle copied and moved files first since moved files may have their source deleted before the move.
	for my $file (keys %copiedFiles) {
	addDirectoriesIfNeeded(dirname($file));
	system "svn", "copy", $copiedFiles{$file}, $file;
	}

	for $patch (@patches) {
	patch($patch);
	}

	removeDirectoriesIfNeeded();

	exit 0;

	sub addDirectoriesIfNeeded($)
	{
	my ($path) = @_;
	my @dirs = File::Spec->splitdir($path);
	my $dir = ".";
	while (scalar @dirs) {
	$dir = File::Spec->catdir($dir, shift @dirs);
	next if exists $checkedDirectories{$dir};
	if (! -e $dir) {
	mkdir $dir or die "Failed to create required directory '$dir' for path '$path'\n";
	system "svn", "add", $dir;
	$checkedDirectories{$dir} = 1;
	}
	elsif (-d $dir) {
	my $svnOutput = svnStatus($dir);
	if ($svnOutput && $svnOutput =~ m#\?\s+$dir\n#) {
	system "svn", "add", $dir;
	}
	$checkedDirectories{$dir} = 1;
	}
	else {
	die "'$dir' is not a directory";
	}
	}
	}

	sub applyPatch($$;$)
	{
	my ($patch, $fullPath, $options) = @_;
	$options = [] if (! $options);
	my $command = "patch " . join(" ", "-p0", @{$options});
	open PATCH, "\| $command" or die "Failed to patch $fullPath\n";
	print PATCH $patch;
	close PATCH;
	}

	sub checksum($)
	{
	my $file = shift;
	open(FILE, $file) or die "Can't open '$file': $!";
	binmode(FILE);
	my $checksum = Digest::MD5->new->addfile(*FILE)->hexdigest();
	close(FILE);
	return $checksum;
	}

	sub fixChangeLogPatch($)
	{
	my $patch = shift;
	my $contextLineCount = 3;

	return $patch if $patch !~ /\n@@ -1,(\d+) \+1,(\d+) @@\n( .\n)+(\+.\n)+( .*\n){$contextLineCount}$/m;
	my ($oldLineCount, $newLineCount) = ($1, $2);
	return $patch if $oldLineCount <= $contextLineCount;

	# The diff(1) command is greedy when matching lines, so a new ChangeLog entry will
	# have lines of context at the top of a patch when the existing entry has the same
	# date and author as the new entry. This nifty loop alters a ChangeLog patch so
	# that the added lines ("+") in the patch always start at the beginning of the
	# patch and there are no initial lines of context.
	my $newPatch;
	my $lineCountInState = 0;
	my $oldContentLineCountReduction = $oldLineCount - $contextLineCount;
	my $newContentLineCountWithoutContext = $newLineCount - $oldLineCount - $oldContentLineCountReduction;
	my ($stateHeader, $statePreContext, $stateNewChanges, $statePostContext) = (1..4);
	my $state = $stateHeader;
	foreach my $line (split(/\n/, $patch)) {
	$lineCountInState++;
	if ($state == $stateHeader && $line =~ /^@@ -1,$oldLineCount \+1,$newLineCount @\@$/) {
	$line = "@@ -1,$contextLineCount +1," . ($newLineCount - $oldContentLineCountReduction) . " @@";
	$lineCountInState = 0;
	$state = $statePreContext;
	} elsif ($state == $statePreContext && substr($line, 0, 1) eq " ") {
	$line = "+" . substr($line, 1);
	if ($lineCountInState == $oldContentLineCountReduction) {
	$lineCountInState = 0;
	$state = $stateNewChanges;
	}
	} elsif ($state == $stateNewChanges && substr($line, 0, 1) eq "+") {
	# No changes to these lines
	if ($lineCountInState == $newContentLineCountWithoutContext) {
	$lineCountInState = 0;
	$state = $statePostContext;
	}
	} elsif ($state == $statePostContext) {
	if (substr($line, 0, 1) eq "+" && $lineCountInState <= $oldContentLineCountReduction) {
	$line = " " . substr($line, 1);
	} elsif ($lineCountInState > $contextLineCount && substr($line, 0, 1) eq " ") {
	next; # Discard
	}
	}
	$newPatch .= $line . "\n";
	}

	return $newPatch;
	}

	sub gitdiff2svndiff($)
	{
	$_ = shift @_;
	if (m#^diff --git a/(.+) b/(.+)#) {
	return "Index: $1";
	} elsif (m/^new file.*/) {
	return "";
	} elsif (m#^index [0-9a-f]{7}\.\.[0-9a-f]{7} [0-9]{6}#) {
	return "===================================================================";
	} elsif (m#^--- a/(.+)#) {
	return "--- $1";
	} elsif (m#^\+\+\+ b/(.+)#) {
	return "+++ $1";
	}
	return $_;
	}

	sub handleBinaryChange($$)
	{
	my ($fullPath, $contents) = @_;
	if ($contents =~ m#((\n[A-Za-z0-9+/]{76})+\n[A-Za-z0-9+/=]{4,76}\n)#) {
	# Addition or Modification
	open FILE, ">", $fullPath or die;
	print FILE decode_base64($1);
	close FILE;
	my $svnOutput = svnStatus($fullPath);
	if ($svnOutput && substr($svnOutput, 0, 1) eq "?") {
	# Addition
	system "svn", "add", $fullPath;
	} else {
	# Modification
	print $svnOutput if $svnOutput;
	}
	} else {
	# Deletion
	system "svn", "rm", $fullPath;
	}
	}

	sub isDirectoryEmptyForRemoval($)
	{
	my ($dir) = @_;
	my $directoryIsEmpty = 1;
	opendir DIR, $dir or die "Could not open '$dir' to list files: $?";
	for (my $item = readdir DIR; $item && $directoryIsEmpty; $item = readdir DIR) {
	next if exists $removeDirectoryIgnoreList{$item};
	if (! -d File::Spec->catdir($dir, $item)) {
	$directoryIsEmpty = 0;
	} else {
	my $svnOutput = svnStatus(File::Spec->catdir($dir, $item));
	next if $svnOutput && substr($svnOutput, 0, 1) eq "D";
	$directoryIsEmpty = 0;
	}
	}
	closedir DIR;
	return $directoryIsEmpty;
	}

	sub patch($)
	{
	my ($patch) = @_;
	return if !$patch;

	unless ($patch =~ m\|^Index: ([^\n]+)\|) {
	my $separator = '-' x 67;
	warn "Failed to find 'Index:' in:\n$separator\n$patch\n$separator\n";
	return;
	}
	my $fullPath = $1;

	my $deletion = 0;
	my $addition = 0;
	my $isBinary = 0;

	$addition = 1 if $patch =~ /\n--- .+\(revision 0\)\n/;
	$deletion = 1 if $patch =~ /\n@@ .* \+0,0 @@/;
	$isBinary = 1 if $patch =~ /\nCannot display: file marked as a binary type\./;

	if (!$addition && !$deletion && !$isBinary) {
	# Standard patch, patch tool can handle this.
	if (basename($fullPath) eq "ChangeLog") {
	my $changeLogDotOrigExisted = -f "${fullPath}.orig";
	applyPatch(setChangeLogDate(fixChangeLogPatch($patch)), $fullPath, ["--fuzz=3"]);
	unlink("${fullPath}.orig") if (! $changeLogDotOrigExisted);
	} else {
	applyPatch($patch, $fullPath);
	}
	} else {
	# Either a deletion, an addition or a binary change.

	addDirectoriesIfNeeded(dirname($fullPath));

	if ($isBinary) {
	# Binary change
	handleBinaryChange($fullPath, $patch);
	} elsif ($deletion) {
	# Deletion
	applyPatch($patch, $fullPath, ["--force"]);
	system "svn", "rm", "--force", $fullPath;
	} else {
	# Addition
	rename($fullPath, "$fullPath.orig") if -e $fullPath;
	applyPatch($patch, $fullPath);
	unlink("$fullPath.orig") if -e "$fullPath.orig" && checksum($fullPath) eq checksum("$fullPath.orig");
	system "svn", "add", $fullPath;
	system "svn", "stat", "$fullPath.orig" if -e "$fullPath.orig";
	}
	}
	}

	sub removeDirectoriesIfNeeded()
	{
	foreach my $dir (reverse sort keys %checkedDirectories) {
	if (isDirectoryEmptyForRemoval($dir)) {
	my $svnOutput;
	open SVN, "svn rm '$dir' \|" or die;
	# Only save the last line since Subversion lists all changed statuses below $dir
	while (<SVN>) {
	$svnOutput = $_;
	}
	close SVN;
	print $svnOutput if $svnOutput;
	}
	}
	}

	sub setChangeLogDate($)
	{
	my $patch = shift;
	my $savedTimeZone = $ENV{'TZ'};
	# Set TZ temporarily so that localtime() is in that time zone
	$ENV{'TZ'} = $changeLogTimeZone;
	my $newDate = strftime("%Y-%m-%d", localtime());
	if (defined $savedTimeZone) {
	$ENV{'TZ'} = $savedTimeZone;
	} else {
	delete $ENV{'TZ'};
	}
	$patch =~ s/(\n\+)\d{4}-[^-]{2}-[^-]{2}( )/$1$newDate$2/;
	return $patch;
	}

	sub svnStatus($)
	{
	my ($fullPath) = @_;
	my $svnStatus;
	open SVN, "svn status --non-interactive --non-recursive '$fullPath' \|" or die;
	if (-d $fullPath) {
	# When running "svn stat" on a directory, we can't assume that only one
	# status will be returned (since any files with a status below the
	# directory will be returned), and we can't assume that the directory will
	# be first (since any files with unknown status will be listed first).
	my $normalizedFullPath = File::Spec->catdir(File::Spec->splitdir($fullPath));
	while (<SVN>) {
	chomp;
	my $normalizedStatPath = File::Spec->catdir(File::Spec->splitdir(substr($_, 7)));
	if ($normalizedFullPath eq $normalizedStatPath) {
	$svnStatus = $_;
	last;
	}
	}
	# Read the rest of the svn command output to avoid a broken pipe warning.
	local $/ = undef;
	<SVN>;
	}
	else {
	# Files will have only one status returned.
	$svnStatus = <SVN>;
	}
	close SVN;
	return $svnStatus;
	}