Is it possible to manually change/reorder the revision numbers (provided topology remains the same)?

Question

In Mercurial , revision numbers are local-clone specific, and they are provided as a facility to point to a specific changeset in a more user-friendly way than a changeset i

Answer 1

Below is an implementation to narrow the graph width using a csscript

The command to copy your repo with the history reordered is

cs-script\cscs.exe HgSortMergeChangesets.cs fromRepo toNewRepo

The file "HgSortMergeChangesets.cs" has the following contents:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;

class Program
{
    static int Main(string[] args)
    {
        if (args.Length != 2)
        {
            Console.WriteLine("usage: SortHgRepo  ");
            return -1;
        }

        var fromRepo = new DirectoryInfo(args[0]);
        var toRepo = new DirectoryInfo(args[1]);


        int errorCode = VerifyParameters(toRepo, fromRepo);
        if (errorCode != 0)
        {
            return errorCode;
        }

        var revsOutput = ExecCmdReturnStdOut("hg.exe", "log -r \"sort(merge(),date)\" -T \"{rev} {date|date}\\n\"", fromRepo.FullName, Console.WriteLine);

        var mergeChangesets = ParseChangesetLog(revsOutput) 
            .ToList();

        ExecCmdReturnStdOut("hg.exe", string.Format("clone -U -r 0 . \"{0}\"", toRepo.FullName), fromRepo.FullName, Console.WriteLine);

        foreach (var changeset in mergeChangesets)
        {
            ExecCmdReturnStdOut("hg.exe", string.Format("pull \"{1}\" -r {0}", changeset.ChangesetId, fromRepo.FullName), toRepo.FullName, Console.WriteLine);
        }

        ExecCmdReturnStdOut("hg.exe", string.Format("pull \"{0}\"", fromRepo.FullName), toRepo.FullName, Console.WriteLine);

        return 0;

    }

    private static int VerifyParameters(DirectoryInfo toRepo, DirectoryInfo fromRepo)
    {
        if (toRepo.Exists)
        {
            Console.WriteLine("The destination repo already exists: {0}", toRepo);
            {
                return -2;
            }
        }


        if (!fromRepo.Exists)
        {
            Console.WriteLine("The source repo does not exists: {0}", fromRepo);
            {
                return -3;
            }
        }

        // make sure the source dir is a repo
        try
        {
            var identity = ExecCmdReturnStdOut("hg.exe", "identify", fromRepo.FullName, Console.WriteLine);
            Console.WriteLine(identity);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
            Console.WriteLine("The source directory, {0}, does not look like an Hg repo.", fromRepo);
            return -4;
        }
        return 0;
    }


    private static IEnumerable ParseChangesetLog(string revsOutput)
    {
        using (var r = new StringReader(revsOutput))
        {
            string line;
            while ((line = r.ReadLine()) != null)
            {
                var spacePos = line.IndexOf(' ');
                yield return new Changeset
                {
                    ChangesetId = int.Parse(line.Substring(0, spacePos)),
                    DateStr = line.Substring(spacePos + 1)
                };
            }
        }
    }

    class Changeset
    {
        public int ChangesetId;
        public string DateStr;
        public DateTime Date { get { return DateTime.ParseExact(DateStr, "ffffd MMM dd H:mm:ss yyyy zzz", null); } }
    }



    public static string ExecCmdReturnStdOut(string program, string args, string workingDir, Action writeline)
    {

        writeline(String.Format("Executing: \"{0}\" {1} in {2}", program, args, workingDir));

        using (var proc = new Process())
        {

            proc.StartInfo.Arguments = args;
            proc.StartInfo.CreateNoWindow = false;
            proc.StartInfo.FileName = program;
            proc.StartInfo.WorkingDirectory = workingDir;
            proc.StartInfo.RedirectStandardError = false;
            proc.StartInfo.RedirectStandardOutput = true;
            proc.StartInfo.UseShellExecute = false;

            proc.Start();

            var output = proc.StandardOutput.ReadToEnd();

            proc.WaitForExit();

            if (proc.ExitCode != 0)
            {
                throw new Exception(string.Format("error code {0} returned when running command {1} in dir {2}", proc.ExitCode, "\"" + program + "\" " + args, workingDir));
            }

            return output;
        }
    }


}