Unable to cherry-pick a merge commit

[vermiculus]

Description

When I cherry-pick a merge commit, I receive the error:

Incorrect usage of "cherryPick". Source commit should not be a merge commit

This is coming from gitGraphAst:cherryPick.

As discussed in #3238, cherry-picking merge commits is a relatively common procedure. While merge commits can now be given an ID (presumably implemented in #3238), that ID cannot be leveraged for cherry-picking - at least in the MWE given below.

Seems to be caused by c147404 (#3080).

Steps to reproduce

See live editor.

Screenshots

No response

Code Sample

gitGraph
  commit
  branch feature
  branch release
  checkout feature
  commit id: "A"
  commit id: "B"
  checkout main
  merge feature id: "M"
  checkout release
  cherry-pick id: "M"

Setup

• Mermaid version: v10.2.3
• Browser and Version: [Chrome, Edge, Firefox] Chrome 114.0.5735.133

Additional Context

No response

[vermiculus]

Is this as simple as removing the following block? I don't see any downstream assumptions, but this codebase is new to me.

  if (sourceCommit.type === commitType.MERGE) {
    let error = new Error(
      'Incorrect usage of "cherryPick". Source commit should not be a merge commit'
    );
    error.hash = {
      text: 'cherryPick ' + sourceId + ' ' + targetId,
      token: 'cherryPick ' + sourceId + ' ' + targetId,
      line: '1',
      loc: { first_line: 1, last_line: 1, first_column: 1, last_column: 1 },
      expected: ['cherry-pick abc'],
    };
    throw error;
  }

[RounakJoshi09]

Hello @sidharthv96 , This seems to be a valid concern/issue regarding cherry-picking merge commits. The issue arises because merge commits have multiple parent commits, leaving Git unsure about which parent to compare against for generating the diff. An additional flag is needed to clarify this. I've reviewed the codebase and believe I can contribute a solution to address this. Could you please assign this issue to me? I'll prioritize working on it.

Feel free to use or adapt this as you see fit.

Source - https://git-scm.com/docs/git-cherry-pick