Tools/Scripts/commit-log-editor - WebKit - Git at Google

 #!/usr/bin/env perl

 # Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc.  All rights reserved.
 # Copyright (C) 2009 Torch Mobile 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 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.

 # Script to put change log comments in as default check-in comment.

 use strict;
 use warnings;
 use Getopt::Long;
 use File::Basename;
 use File::Spec;
 use FindBin;
 use lib $FindBin::Bin;
 use VCSUtils;
 use webkitdirs;

 sub commitMessageFromChangeLogEntry($);
 sub sortKey($);
 sub createCommitMessage(@);
 sub loadTermReadKey();
 sub normalizeLineEndings($$);
 sub patchAuthorshipString($$$);
 sub removeLongestCommonPrefixEndingInNewline(\%);
 sub isCommitLogEditor($);

 my $endl = "\n";

 sub printUsageAndExit
 {
     my $programName = basename($0);
     print STDERR <<EOF;
 Usage: $programName [--regenerate-log] <log file>
        $programName --print-log <ChangeLog file> [<ChangeLog file>...]
        $programName --help
 EOF
     exit 1;
 }

 my $help = 0;
 my $printLog = 0;
 my $regenerateLog = 0;

 my $getOptionsResult = GetOptions(
     'help' => \$help,
     'print-log' => \$printLog,
     'regenerate-log' => \$regenerateLog,
 );

 if (!$getOptionsResult || $help) {
     printUsageAndExit();
 }

 die "Can't specify both --print-log and --regenerate-log\n" if $printLog && $regenerateLog;

 if ($printLog) {
     printUsageAndExit() unless @ARGV;
     print createCommitMessage(@ARGV);
     exit 0;
 }

 my $log = $ARGV[0];
 if (!$log) {
     printUsageAndExit();
 }

 my $baseDir = baseProductDir();

 my $editor;
 if (isGit()) {
     $editor = $ENV{GIT_LOG_EDITOR};
     $editor = `git config --global --get core.editor` if !$editor;
 }

 $editor = $ENV{SVN_LOG_EDITOR} if !$editor;
 $editor = $ENV{CVS_LOG_EDITOR} if !$editor;
 $editor = "" if $editor && isCommitLogEditor($editor);

 my $splitEditor = 1;
 if (!$editor) {
     my $builtEditorApplication = "$baseDir/Release/Commit Log Editor.app/Contents/MacOS/Commit Log Editor";
     if (-x $builtEditorApplication) {
         $editor = $builtEditorApplication;
         $splitEditor = 0;
     }
 }
 if (!$editor) {
     my $builtEditorApplication = "$baseDir/Debug/Commit Log Editor.app/Contents/MacOS/Commit Log Editor";
     if (-x $builtEditorApplication) {
         $editor = $builtEditorApplication;
         $splitEditor = 0;
     }
 }
 if (!$editor) {
     my $builtEditorApplication = "$ENV{HOME}/Applications/Commit Log Editor.app/Contents/MacOS/Commit Log Editor";
     if (-x $builtEditorApplication) {
         $editor = $builtEditorApplication;
         $splitEditor = 0;
     }
 }

 $editor = $ENV{EDITOR} if !$editor;
 $editor = "/usr/bin/vi" if !$editor;

 my @editor;
 if ($splitEditor) {
     @editor = split ' ', $editor;
 } else {
     @editor = ($editor);
 }

 my $inChangesToBeCommitted = !isGit();
 my $foundCutLine = 0;
 my @changeLogs = ();
 my $logContents = "";
 my $existingLog = 0;
 open LOG, $log or die "Could not open the log file.";
 while (my $curLine = <LOG>) {
     if (isGit()) {
         if ($curLine eq "# ------------------------ >8 ------------------------\n") {
           $foundCutLine = 1;
         } elsif ($curLine =~ /^# Changes to be committed:$/) {
             $inChangesToBeCommitted = 1;
         } elsif ($inChangesToBeCommitted && $curLine =~ /^# \S/) {
             $inChangesToBeCommitted = 0;
         }
     }

     if (!isGit() || $curLine =~ /^#/ || $foundCutLine) {
         $logContents .= $curLine;
     } else {
         # $_ contains the current git log message
         # (without the log comment info). We don't need it.
     }
     $existingLog = isGit() && !$foundCutLine && !($curLine =~ /^#/ || $curLine =~ /^\s*$/) unless $existingLog;
     push @changeLogs, makeFilePathRelative($1) if $inChangesToBeCommitted && ($curLine =~ /^(?:M|A)....(.*ChangeLog)\r?\n?$/ || $curLine =~ /^#\t(?:modified|new file):   (.*ChangeLog)$/) && $curLine !~ /-ChangeLog$/;
 }
 close LOG;

 @changeLogs = map { $ENV{GIT_PREFIX} . $_ } @changeLogs if isGit();

 # We want to match the line endings of the existing log file in case they're
 # different from perl's line endings.
 $endl = $1 if $logContents =~ /(\r?\n)/;

 my $keepExistingLog = 1;
 if ($regenerateLog && $existingLog && scalar(@changeLogs) > 0 && loadTermReadKey()) {
     print "Existing log message detected, Use 'r' to regenerate log message from ChangeLogs, or any other key to keep the existing message.\n";
     Term::ReadKey::ReadMode('cbreak');
     my $key = Term::ReadKey::ReadKey(0);
     Term::ReadKey::ReadMode('normal');
     $keepExistingLog = 0 if ($key eq "r");
 }

 # Don't change anything if there's already a log message (as can happen with git-commit --amend).
 exec (@editor, @ARGV) if $existingLog && $keepExistingLog;

 my $first = 1;
 open NEWLOG, ">$log.edit" or die;
 if (isGit() && @changeLogs == 0) {
     # populate git commit message with WebKit-format ChangeLog entries unless explicitly disabled
     my $branch = gitBranch();
     chomp(my $webkitGenerateCommitMessage = `git config --bool branch.$branch.webkitGenerateCommitMessage`);
     if ($webkitGenerateCommitMessage eq "") {
         chomp($webkitGenerateCommitMessage = `git config --bool core.webkitGenerateCommitMessage`);
     }
     if ($webkitGenerateCommitMessage ne "false") {
         my %changeLogSort;
         my %changeLogContents;
         open my $changeLogEntries, "-|", "$FindBin::Bin/prepare-ChangeLog --git-index --no-write --no-style --delimiters" or die "prepare-ChangeLog failed: $!.\n";

         while (!eof($changeLogEntries)) {
             my $label = <$changeLogEntries>;
             chomp $label;
             $label =~ s/:$//;
             ($changeLogContents{$label}) = commitMessageFromChangeLogEntry($changeLogEntries);
             $changeLogSort{sortKey($label)} = $label;
         }
         close $changeLogEntries;

         my $commonPrefix = removeLongestCommonPrefixEndingInNewline(%changeLogContents);

         my @result;
         push @result, normalizeLineEndings($commonPrefix, $endl);
         for my $sortKey (sort keys %changeLogSort) {
             my $label = $changeLogSort{$sortKey};
             next if ($changeLogContents{$label} eq "\n");
             if (keys %changeLogSort > 1) {
                 push @result, normalizeLineEndings("\n", $endl);
                 push @result, normalizeLineEndings("$label: ", $endl);
             }
             push @result, normalizeLineEndings($changeLogContents{$label}, $endl);
         }

         print NEWLOG join '', @result;
     }
 } else {
     print NEWLOG createCommitMessage(@changeLogs);
 }
 print NEWLOG $logContents;
 close NEWLOG;

 system (@editor, "$log.edit");

 open NEWLOG, "$log.edit" or exit;
 my $foundComment = 0;
 while (<NEWLOG>) {
     $foundComment = 1 if (/\S/ && !/^CVS:/);
 }
 close NEWLOG;

 if ($foundComment) {
     open NEWLOG, "$log.edit" or die;
     open LOG, ">$log" or die;
     while (<NEWLOG>) {
         print LOG;
     }
     close LOG;
     close NEWLOG;
 }

 unlink "$log.edit";

 sub commitMessageFromChangeLogEntry($)
 {
     my ($changeLog) = @_;

     my $commitMessage = "";
     my $blankLines = "";
     my $lineCount = 0;
     my $date = "";
     my $author = "";
     my $email = "";
     my $hasAuthorInfoToWrite = 0;

     while (<$changeLog>) {
         if (/^\S/) {
             last if $commitMessage;
         }
         if (/\S/) {
             $commitMessage .= $blankLines if $commitMessage;
             $blankLines = "";

             my $line = $_;
             # Remove indentation spaces
             $line =~ s/^ {8}//;

             # Grab the author and the date line
             if ($line =~ m/^([0-9]{4}-[0-9]{2}-[0-9]{2})\s+(.*[^\s])\s+<(.*)>/ && $lineCount == 0) {
                 $date = $1;
                 $author = $2;
                 $email = $3;
                 $hasAuthorInfoToWrite = 1;
                 next;
             }

             if ($hasAuthorInfoToWrite) {
                 my $isReviewedByLine = $line =~ m/^(?:Reviewed|Rubber[ \-]?stamped) by/;
                 my $isModifiedFileLine = $line =~ m/^\* .*:/;

                 # Insert the authorship line if needed just above the "Reviewed by" line or the
                 # first modified file (whichever comes first).
                 if ($isReviewedByLine || $isModifiedFileLine) {
                     $hasAuthorInfoToWrite = 0;
                     my $authorshipString = patchAuthorshipString($author, $email, $date);
                     if ($authorshipString) {
                         $commitMessage .= "$authorshipString\n";
                         $commitMessage .= "\n" if $isModifiedFileLine;
                     }
                 }
             }


             $lineCount++;
             $commitMessage .= $line;
         } else {
             $blankLines .= $_;
         }
     }
     return ($commitMessage, $hasAuthorInfoToWrite, $date, $author, $email);
 }

 sub sortKey($)
 {
     my ($label) = @_;
     my $sortKey = lc $label;
     if ($label eq "top level") {
         $sortKey = "";
     } elsif ($label eq "LayoutTests") {
         $sortKey = lc "~, LayoutTests last";
     }
     return $sortKey;
 }

 sub createCommitMessage(@)
 {
     my @changeLogs = @_;

     my $topLevel = determineVCSRoot();

     my %changeLogSort;
     my %changeLogContents;
     for my $changeLog (@changeLogs) {
         open my $changeLogFile, $changeLog or die "Can't open $changeLog";

         my ($contents, $hasAuthorInfoToWrite, $date, $author, $email) = commitMessageFromChangeLogEntry($changeLogFile);
         if ($hasAuthorInfoToWrite) {
             # We didn't find anywhere to put the authorship info, so just put it at the end.
             my $authorshipString = patchAuthorshipString($author, $email, $date);
             $contents .= "\n$authorshipString\n" if $authorshipString;
             $hasAuthorInfoToWrite = 0;
         }

         close $changeLogFile;

         $changeLog = File::Spec->abs2rel(File::Spec->rel2abs($changeLog), $topLevel);

         my $label = dirname($changeLog);
         $label = "top level" unless length $label;

         $changeLogSort{sortKey($label)} = $label;
         $changeLogContents{$label} = $contents;
     }

     my $commonPrefix = removeLongestCommonPrefixEndingInNewline(%changeLogContents);

     my @result;
     push @result, normalizeLineEndings($commonPrefix, $endl);
     for my $sortKey (sort keys %changeLogSort) {
         my $label = $changeLogSort{$sortKey};
         next if ($changeLogContents{$label} eq "\n");
         if (keys %changeLogSort > 1) {
             push @result, normalizeLineEndings("\n", $endl);
             push @result, normalizeLineEndings("$label:\n", $endl);
         }
         push @result, normalizeLineEndings($changeLogContents{$label}, $endl);
     }

     return join '', @result;
 }

 sub loadTermReadKey()
 {
     eval { require Term::ReadKey; };
     return !$@;
 }

 sub normalizeLineEndings($$)
 {
     my ($string, $endl) = @_;
     $string =~ s/\r?\n/$endl/g;
     return $string;
 }

 sub patchAuthorshipString($$$)
 {
     my ($authorName, $authorEmail, $authorDate) = @_;

     return if $authorEmail eq changeLogEmailAddress();
     return "Patch by $authorName <$authorEmail> on $authorDate";
 }

 sub removeLongestCommonPrefixEndingInNewline(\%)
 {
     my ($hashOfStrings) = @_;

     my @strings = values %{$hashOfStrings};
     return "" unless @strings > 1;

     my $prefix = shift @strings;
     my $prefixLength = length $prefix;
     foreach my $string (@strings) {
         while ($prefixLength) {
             last if substr($string, 0, $prefixLength) eq $prefix;
             --$prefixLength;
             $prefix = substr($prefix, 0, -1);
         }
         last unless $prefixLength;
     }

     return "" unless $prefixLength;

     my $lastNewline = rindex($prefix, "\n");
     return "" unless $lastNewline > 0;

     foreach my $key (keys %{$hashOfStrings}) {
         $hashOfStrings->{$key} = substr($hashOfStrings->{$key}, $lastNewline);
     }
     return substr($prefix, 0, $lastNewline);
 }

 sub isCommitLogEditor($)
 {
     my $editor = shift;
     return $editor =~ m/commit-log-editor/;
 }
	#!/usr/bin/env perl

	# Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
	# Copyright (C) 2009 Torch Mobile 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 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.

	# Script to put change log comments in as default check-in comment.

	use strict;
	use warnings;
	use Getopt::Long;
	use File::Basename;
	use File::Spec;
	use FindBin;
	use lib $FindBin::Bin;
	use VCSUtils;
	use webkitdirs;

	sub commitMessageFromChangeLogEntry($);
	sub sortKey($);
	sub createCommitMessage(@);
	sub loadTermReadKey();
	sub normalizeLineEndings($$);
	sub patchAuthorshipString($$$);
	sub removeLongestCommonPrefixEndingInNewline(\%);
	sub isCommitLogEditor($);

	my $endl = "\n";

	sub printUsageAndExit
	{
	my $programName = basename($0);
	print STDERR <<EOF;
	Usage: $programName [--regenerate-log] <log file>
	$programName --print-log <ChangeLog file> [<ChangeLog file>...]
	$programName --help
	EOF
	exit 1;
	}

	my $help = 0;
	my $printLog = 0;
	my $regenerateLog = 0;

	my $getOptionsResult = GetOptions(
	'help' => \$help,
	'print-log' => \$printLog,
	'regenerate-log' => \$regenerateLog,
	);

	if (!$getOptionsResult \|\| $help) {
	printUsageAndExit();
	}

	die "Can't specify both --print-log and --regenerate-log\n" if $printLog && $regenerateLog;

	if ($printLog) {
	printUsageAndExit() unless @ARGV;
	print createCommitMessage(@ARGV);
	exit 0;
	}

	my $log = $ARGV[0];
	if (!$log) {
	printUsageAndExit();
	}

	my $baseDir = baseProductDir();

	my $editor;
	if (isGit()) {
	$editor = $ENV{GIT_LOG_EDITOR};
	$editor = `git config --global --get core.editor` if !$editor;
	}

	$editor = $ENV{SVN_LOG_EDITOR} if !$editor;
	$editor = $ENV{CVS_LOG_EDITOR} if !$editor;
	$editor = "" if $editor && isCommitLogEditor($editor);

	my $splitEditor = 1;
	if (!$editor) {
	my $builtEditorApplication = "$baseDir/Release/Commit Log Editor.app/Contents/MacOS/Commit Log Editor";
	if (-x $builtEditorApplication) {
	$editor = $builtEditorApplication;
	$splitEditor = 0;
	}
	}
	if (!$editor) {
	my $builtEditorApplication = "$baseDir/Debug/Commit Log Editor.app/Contents/MacOS/Commit Log Editor";
	if (-x $builtEditorApplication) {
	$editor = $builtEditorApplication;
	$splitEditor = 0;
	}
	}
	if (!$editor) {
	my $builtEditorApplication = "$ENV{HOME}/Applications/Commit Log Editor.app/Contents/MacOS/Commit Log Editor";
	if (-x $builtEditorApplication) {
	$editor = $builtEditorApplication;
	$splitEditor = 0;
	}
	}

	$editor = $ENV{EDITOR} if !$editor;
	$editor = "/usr/bin/vi" if !$editor;

	my @editor;
	if ($splitEditor) {
	@editor = split ' ', $editor;
	} else {
	@editor = ($editor);
	}

	my $inChangesToBeCommitted = !isGit();
	my $foundCutLine = 0;
	my @changeLogs = ();
	my $logContents = "";
	my $existingLog = 0;
	open LOG, $log or die "Could not open the log file.";
	while (my $curLine = <LOG>) {
	if (isGit()) {
	if ($curLine eq "# ------------------------ >8 ------------------------\n") {
	$foundCutLine = 1;
	} elsif ($curLine =~ /^# Changes to be committed:$/) {
	$inChangesToBeCommitted = 1;
	} elsif ($inChangesToBeCommitted && $curLine =~ /^# \S/) {
	$inChangesToBeCommitted = 0;
	}
	}

	if (!isGit() \|\| $curLine =~ /^#/ \|\| $foundCutLine) {
	$logContents .= $curLine;
	} else {
	# $_ contains the current git log message
	# (without the log comment info). We don't need it.
	}
	$existingLog = isGit() && !$foundCutLine && !($curLine =~ /^#/ \|\| $curLine =~ /^\s*$/) unless $existingLog;
	push @changeLogs, makeFilePathRelative($1) if $inChangesToBeCommitted && ($curLine =~ /^(?:M\|A)....(.ChangeLog)\r?\n?$/ \|\| $curLine =~ /^#\t(?:modified\|new file): (.ChangeLog)$/) && $curLine !~ /-ChangeLog$/;
	}
	close LOG;

	@changeLogs = map { $ENV{GIT_PREFIX} . $_ } @changeLogs if isGit();

	# We want to match the line endings of the existing log file in case they're
	# different from perl's line endings.
	$endl = $1 if $logContents =~ /(\r?\n)/;

	my $keepExistingLog = 1;
	if ($regenerateLog && $existingLog && scalar(@changeLogs) > 0 && loadTermReadKey()) {
	print "Existing log message detected, Use 'r' to regenerate log message from ChangeLogs, or any other key to keep the existing message.\n";
	Term::ReadKey::ReadMode('cbreak');
	my $key = Term::ReadKey::ReadKey(0);
	Term::ReadKey::ReadMode('normal');
	$keepExistingLog = 0 if ($key eq "r");
	}

	# Don't change anything if there's already a log message (as can happen with git-commit --amend).
	exec (@editor, @ARGV) if $existingLog && $keepExistingLog;

	my $first = 1;
	open NEWLOG, ">$log.edit" or die;
	if (isGit() && @changeLogs == 0) {
	# populate git commit message with WebKit-format ChangeLog entries unless explicitly disabled
	my $branch = gitBranch();
	chomp(my $webkitGenerateCommitMessage = `git config --bool branch.$branch.webkitGenerateCommitMessage`);
	if ($webkitGenerateCommitMessage eq "") {
	chomp($webkitGenerateCommitMessage = `git config --bool core.webkitGenerateCommitMessage`);
	}
	if ($webkitGenerateCommitMessage ne "false") {
	my %changeLogSort;
	my %changeLogContents;
	open my $changeLogEntries, "-\|", "$FindBin::Bin/prepare-ChangeLog --git-index --no-write --no-style --delimiters" or die "prepare-ChangeLog failed: $!.\n";

	while (!eof($changeLogEntries)) {
	my $label = <$changeLogEntries>;
	chomp $label;
	$label =~ s/:$//;
	($changeLogContents{$label}) = commitMessageFromChangeLogEntry($changeLogEntries);
	$changeLogSort{sortKey($label)} = $label;
	}
	close $changeLogEntries;

	my $commonPrefix = removeLongestCommonPrefixEndingInNewline(%changeLogContents);

	my @result;
	push @result, normalizeLineEndings($commonPrefix, $endl);
	for my $sortKey (sort keys %changeLogSort) {
	my $label = $changeLogSort{$sortKey};
	next if ($changeLogContents{$label} eq "\n");
	if (keys %changeLogSort > 1) {
	push @result, normalizeLineEndings("\n", $endl);
	push @result, normalizeLineEndings("$label: ", $endl);
	}
	push @result, normalizeLineEndings($changeLogContents{$label}, $endl);
	}

	print NEWLOG join '', @result;
	}
	} else {
	print NEWLOG createCommitMessage(@changeLogs);
	}
	print NEWLOG $logContents;
	close NEWLOG;

	system (@editor, "$log.edit");

	open NEWLOG, "$log.edit" or exit;
	my $foundComment = 0;
	while (<NEWLOG>) {
	$foundComment = 1 if (/\S/ && !/^CVS:/);
	}
	close NEWLOG;

	if ($foundComment) {
	open NEWLOG, "$log.edit" or die;
	open LOG, ">$log" or die;
	while (<NEWLOG>) {
	print LOG;
	}
	close LOG;
	close NEWLOG;
	}

	unlink "$log.edit";

	sub commitMessageFromChangeLogEntry($)
	{
	my ($changeLog) = @_;

	my $commitMessage = "";
	my $blankLines = "";
	my $lineCount = 0;
	my $date = "";
	my $author = "";
	my $email = "";
	my $hasAuthorInfoToWrite = 0;

	while (<$changeLog>) {
	if (/^\S/) {
	last if $commitMessage;
	}
	if (/\S/) {
	$commitMessage .= $blankLines if $commitMessage;
	$blankLines = "";

	my $line = $_;
	# Remove indentation spaces
	$line =~ s/^ {8}//;

	# Grab the author and the date line
	if ($line =~ m/^([0-9]{4}-[0-9]{2}-[0-9]{2})\s+(.[^\s])\s+<(.)>/ && $lineCount == 0) {
	$date = $1;
	$author = $2;
	$email = $3;
	$hasAuthorInfoToWrite = 1;
	next;
	}

	if ($hasAuthorInfoToWrite) {
	my $isReviewedByLine = $line =~ m/^(?:Reviewed\|Rubber[ \-]?stamped) by/;
	my $isModifiedFileLine = $line =~ m/^\* .*:/;

	# Insert the authorship line if needed just above the "Reviewed by" line or the
	# first modified file (whichever comes first).
	if ($isReviewedByLine \|\| $isModifiedFileLine) {
	$hasAuthorInfoToWrite = 0;
	my $authorshipString = patchAuthorshipString($author, $email, $date);
	if ($authorshipString) {
	$commitMessage .= "$authorshipString\n";
	$commitMessage .= "\n" if $isModifiedFileLine;
	}
	}
	}


	$lineCount++;
	$commitMessage .= $line;
	} else {
	$blankLines .= $_;
	}
	}
	return ($commitMessage, $hasAuthorInfoToWrite, $date, $author, $email);
	}

	sub sortKey($)
	{
	my ($label) = @_;
	my $sortKey = lc $label;
	if ($label eq "top level") {
	$sortKey = "";
	} elsif ($label eq "LayoutTests") {
	$sortKey = lc "~, LayoutTests last";
	}
	return $sortKey;
	}

	sub createCommitMessage(@)
	{
	my @changeLogs = @_;

	my $topLevel = determineVCSRoot();

	my %changeLogSort;
	my %changeLogContents;
	for my $changeLog (@changeLogs) {
	open my $changeLogFile, $changeLog or die "Can't open $changeLog";

	my ($contents, $hasAuthorInfoToWrite, $date, $author, $email) = commitMessageFromChangeLogEntry($changeLogFile);
	if ($hasAuthorInfoToWrite) {
	# We didn't find anywhere to put the authorship info, so just put it at the end.
	my $authorshipString = patchAuthorshipString($author, $email, $date);
	$contents .= "\n$authorshipString\n" if $authorshipString;
	$hasAuthorInfoToWrite = 0;
	}

	close $changeLogFile;

	$changeLog = File::Spec->abs2rel(File::Spec->rel2abs($changeLog), $topLevel);

	my $label = dirname($changeLog);
	$label = "top level" unless length $label;

	$changeLogSort{sortKey($label)} = $label;
	$changeLogContents{$label} = $contents;
	}

	my $commonPrefix = removeLongestCommonPrefixEndingInNewline(%changeLogContents);

	my @result;
	push @result, normalizeLineEndings($commonPrefix, $endl);
	for my $sortKey (sort keys %changeLogSort) {
	my $label = $changeLogSort{$sortKey};
	next if ($changeLogContents{$label} eq "\n");
	if (keys %changeLogSort > 1) {
	push @result, normalizeLineEndings("\n", $endl);
	push @result, normalizeLineEndings("$label:\n", $endl);
	}
	push @result, normalizeLineEndings($changeLogContents{$label}, $endl);
	}

	return join '', @result;
	}

	sub loadTermReadKey()
	{
	eval { require Term::ReadKey; };
	return !$@;
	}

	sub normalizeLineEndings($$)
	{
	my ($string, $endl) = @_;
	$string =~ s/\r?\n/$endl/g;
	return $string;
	}

	sub patchAuthorshipString($$$)
	{
	my ($authorName, $authorEmail, $authorDate) = @_;

	return if $authorEmail eq changeLogEmailAddress();
	return "Patch by $authorName <$authorEmail> on $authorDate";
	}

	sub removeLongestCommonPrefixEndingInNewline(\%)
	{
	my ($hashOfStrings) = @_;

	my @strings = values %{$hashOfStrings};
	return "" unless @strings > 1;

	my $prefix = shift @strings;
	my $prefixLength = length $prefix;
	foreach my $string (@strings) {
	while ($prefixLength) {
	last if substr($string, 0, $prefixLength) eq $prefix;
	--$prefixLength;
	$prefix = substr($prefix, 0, -1);
	}
	last unless $prefixLength;
	}

	return "" unless $prefixLength;

	my $lastNewline = rindex($prefix, "\n");
	return "" unless $lastNewline > 0;

	foreach my $key (keys %{$hashOfStrings}) {
	$hashOfStrings->{$key} = substr($hashOfStrings->{$key}, $lastNewline);
	}
	return substr($prefix, 0, $lastNewline);
	}

	sub isCommitLogEditor($)
	{
	my $editor = shift;
	return $editor =~ m/commit-log-editor/;
	}