resolve-changelogs

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            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 fixMergedChangeLogs($;@)
{
    my $revisionRange = shift;
    my @changedFiles = @_;

    if (scalar(@changedFiles) < 1) {
        # Read in list of files changed in $revisionRange
        open GIT, "-|", $GIT, "diff", "--name-only", $revisionRange || die;
        push @changedFiles, <GIT>;
        close GIT || die;
        die "No changed files in $revisionRange" if scalar(@changedFiles) < 1;
        chomp @changedFiles;
    }

    my @changeLogs = grep { defined $_ } map { findChangeLog($_) } @changedFiles;
    die "No changed ChangeLog files in $revisionRange" if scalar(@changeLogs) < 1;

    system("$GIT filter-branch --tree-filter 'PREVIOUS_COMMIT=\`$GIT rev-parse \$GIT_COMMIT^\` && MAPPED_PREVIOUS_COMMIT=\`map \$PREVIOUS_COMMIT\` $0 -f \"" . join('" "', @changeLogs) . "\"' $revisionRange");

    # On success, remove the backup refs directory
    if (WEXITSTATUS($?) == 0) {
        rmtree(qw(.git/refs/original));
    }
}

sub fixOneMergedChangeLog($)
{
    my $file = shift;
    my $patch;

    # Read in patch for incorrectly merged ChangeLog entry
    {
        local $/ = undef;
        open GIT, "-|", $GIT, "diff", ($ENV{GIT_COMMIT} || "HEAD") . "^", $file || die;
        $patch = <GIT>;
        close GIT || die;
    }

    # Always checkout the previous commit's copy of the ChangeLog
    system($GIT, "checkout", $ENV{MAPPED_PREVIOUS_COMMIT} || "HEAD^", $file);

    # The patch must have 0 or more lines of context, then 1 or more lines
    # of additions, and then 1 or more lines of context.  If not, we skip it.
    if ($patch =~ /\n@@ -(\d+),(\d+) \+(\d+),(\d+) @@\n( .*\n)*((\+.*\n)+)( .*\n)+$/m) {
        # Copy the header from the original patch.
        my $newPatch = substr($patch, 0, index($patch, "@@ -${1},${2} +${3},${4} @@"));

        # Generate a new set of line numbers and patch lengths.  Our new
        # patch will start with the lines for the fixed ChangeLog entry,
        # then have 3 lines of context from the top of the current file to
        # make the patch apply cleanly.
        $newPatch .= "@@ -1,3 +1," . ($4 - $2 + 3) . " @@\n";

        # We assume that top few lines of the ChangeLog entry are actually
        # at the bottom of the list of added lines (due to the way the patch
        # algorithm works), so we simply search through the lines until we
        # find the date line, then move the rest of the lines to the top.
        my @patchLines = map { $_ . "\n" } split(/\n/, $6);
        foreach my $i (0 .. $#patchLines) {
            if ($patchLines[$i] =~ /^\+\d{4}-\d{2}-\d{2}  /) {
                unshift(@patchLines, splice(@patchLines, $i, scalar(@patchLines) - $i));
                last;
            }
        }

        $newPatch .= join("", @patchLines);

        # Add 3 lines of context to the end
        open FILE, "<", $file || die;
        for (my $i = 0; $i < 3; $i++) {
            $newPatch .= " " . <FILE>;
        }
        close FILE;

        # Apply the new patch
        open(PATCH, "| patch -p1 $file > /dev/null") || die;
        print PATCH $newPatch;
        close(PATCH) || die;

        # Run "git add" on the fixed ChangeLog file
        system($GIT, "add", $file);

        showStatus($file, 1);
    } elsif ($patch) {
        # Restore the current copy of the ChangeLog file since we can't repatch it
        system($GIT, "checkout", $ENV{GIT_COMMIT} || "HEAD", $file);
        print STDERR "WARNING: Last change to ${file} could not be fixed and re-merged.\n" if $printWarnings;
    }
}

sub mergeChanges($$$)
{
    my ($fileMine, $fileOlder, $fileNewer) = @_;

    my $traditionalReject = $fileMine =~ /\.rej$/ ? 1 : 0;

    local $/ = undef;

    my $patch;
    if ($traditionalReject) {
        open(DIFF, "<", $fileMine);
        $patch = <DIFF>;
        close(DIFF);
        rename($fileMine, "$fileMine.save");
        rename($fileOlder, "$fileOlder.save");
    } else {
        open(DIFF, "-|", qw(diff -u), $fileOlder, $fileMine) || die;
        $patch = <DIFF>;
        close(DIFF);
    }

    unlink("${fileNewer}.orig");
    unlink("${fileNewer}.rej");

    open(PATCH, "| patch --fuzz=3 $fileNewer > /dev/null") || die;
    print PATCH fixChangeLogPatch($patch);
    close(PATCH);

    my $result;

    # Refuse to merge the patch if it did not apply cleanly
    if (-e "${fileNewer}.rej") {
        unlink("${fileNewer}.rej");
        unlink($fileNewer);
        rename("${fileNewer}.orig", $fileNewer);
        $result = 0;
    } else {
        unlink("${fileNewer}.orig");
        $result = 1;
    }

    if ($traditionalReject) {
        rename("$fileMine.save", $fileMine);
        rename("$fileOlder.save", $fileOlder);
    }

    return $result;
}

sub parseFixMerged($$;$)
{
    my ($switchName, $key, $value) = @_;
    if (defined $key) {
        if (defined findChangeLog($key)) {
            unshift(@ARGV, $key);
            $fixMerged = "";
        } else {
            $fixMerged = $key;
        }
    } else {
        $fixMerged = "";
    }
}

sub removeChangeLogArguments()
{
    my @results = ();

    for (my $i = 0; $i < scalar(@ARGV); ) {
        my $file = findChangeLog($ARGV[$i]);
        if (defined $file) {
            splice(@ARGV, $i, 1);
            push @results, $file;
        } else {
            $i++;
        }
    }

    return @results;
}

sub resolveChangeLog($)
{
    my ($file) = @_;

    my ($fileMine, $fileOlder, $fileNewer) = conflictFiles($file);

    return unless $fileMine && $fileOlder && $fileNewer;

    if (mergeChanges($fileMine, $fileOlder, $fileNewer)) {
        if ($file ne $fileNewer) {
            unlink($file);
            rename($fileNewer, $file) || die;
        }
        unlink($fileMine, $fileOlder);
        resolveConflict($file);
        showStatus($file, 1);
    } else {
        showStatus($file);
        print STDERR "WARNING: ${file} could not be merged using fuzz level 3.\n" if $printWarnings;
        unlink($fileMine, $fileOlder, $fileNewer) if isGit();
    }
}

sub resolveConflict($)
{
    my ($file) = @_;

    if (isSVN()) {
        system($SVN, "resolved", $file);
    } elsif (isGit()) {
        system($GIT, "add", $file);
    } else {
        die "Unknown version control system";
    }
}

sub showStatus($;$)
{
    my ($file, $isConflictResolved) = @_;

    if (isSVN()) {
        system($SVN, "status", $file);
    } elsif (isGit()) {
        my @args = qw(--name-status);
        unshift @args, qw(--cached) if $isConflictResolved;
        system($GIT, "diff", @args, $file);
    } else {
        die "Unknown version control system";
    }
}