Commit sotring is unstable

[ikedam]

Expected Behavior

The order of log entries are always same for any configurations if options.commits.sort_by is not changed.

Actual Behavior

The order of log entries differs for different configurations, even if options.commits.sort_by is not changed.
This means the sorting for commit is performed with an unstable sort algorithm.

Steps to Reproduce (including precondition)

1. Create a changelog for git-chglog@v0.11.0:

   $ ./git-chglog v0.11.0 >changelog1.md 
   

2. Change the configuration:

   diff --git a/.chglog/config.yml b/.chglog/config.yml
   index 074a182..5473a51 100755
   --- a/.chglog/config.yml
   +++ b/.chglog/config.yml
   @@ -20,7 +20,7 @@ options:
          refactor: Code Refactoring
          chore: Chores
      header:
   -    pattern: "^(\\w*)(?:\\(([\\w\\$\\.\\-\\*\\s]*)\\))?\\:\\s(.*)$"
   +    pattern: "^(\\w*)(?:\\(([\\w\\$\\.\\-\\*\\s]*)\\))?\\:\\s(update module .*)$"
        pattern_maps:
          - Type
          - Scope
   

   • This means to generate a changelog only with logs started with "update module ...".

3. Create a changelog for git-chglog@v0.11.0 with the new configuration:

   $ ./git-chglog v0.11.0 >changelog2.md 
   

4. Compare them:

   $ diff -u changelog1.md changelog2.md
   

   • Attached this output: diff_of_changelogs.txt
   • There are differences not only for removed lines but also for added lines. This is caused for the order of logs changed.

I found this behavior when I updated the git-chglog configuration for my repository to pick new commits. I expected new logs, but didn't expected changing the order of logs.

Screenshot on This Problem (if possible)

N/A

Your Environment

• OS: golang:1.19.1-bullseye (Tested with docker)
• git-chglog version: v0.15.1 (Built in golang:1.19.1-bullseye)