I want to perform an interactive rebase in order to squash some commits.

The way I do this is:

• use git log to search for the commits I want to squash
• count the number of commits from HEAD
• use git rebase -i HEAD~n where n is the number of commits from HEAD

Is this the wrong method? I have been using this technique for a while and sometimes wondered why the number of commits doesn’t match up.

To demonstrate, here is the output from git log --pretty=format:"%h%x09%an%x09%ad%x09%s".

130f00e me              Fri Apr 19 16:37:15 2024 +0000  commit message
c7bb70c me on github    Fri Apr 19 17:08:28 2024 +0100  Merge pull request #419 from company/MY-DEV-BRANCH
3e3f411 me              Fri Apr 19 16:07:42 2024 +0000  commit message
47e769e colleague       Fri Apr 19 17:00:26 2024 +0100  Merge pull request #418 from company/colleague -patch-28
998be63 colleague       Fri Apr 19 16:59:53 2024 +0100  commit message
7b75da8 colleague       Fri Apr 19 16:59:31 2024 +0100  commit message
c7f0da1 colleague       Fri Apr 19 15:54:59 2024 +0100  Merge pull request #417 from company/mycolleague/HIS-DEV_BRANCH
43e927d colleague       Fri Apr 19 15:54:49 2024 +0100  Merge branch 'master' into mycolleague/HIS-DEV_BRANCH
06d62f2 colleague       Fri Apr 19 14:52:50 2024 +0000  commit message
3de4d90 me on github    Fri Apr 19 15:08:37 2024 +0100  Merge pull request #414 from company/MY-DEV-BRANCH
374add4 me              Fri Apr 19 14:00:36 2024 +0000  commit message
ba4fd3b me              Fri Apr 19 14:00:07 2024 +0000  Merge remote-tracking branch 'origin/master' into MY-DEV-BRANCH
aed07ae me              Fri Apr 19 13:37:31 2024 +0000  commit message
44e119d colleague       Fri Apr 19 10:09:46 2024 +0100  Merge pull request #416 from company/colleague -patch-46
da11abe colleague       Fri Apr 19 10:09:39 2024 +0100  commit message
a74b81a colleague       Fri Apr 19 10:09:18 2024 +0100  commit message
80b4003 colleague       Fri Apr 19 09:51:56 2024 +0100  Merge pull request #415 from company/mycolleague/HIS-DEV_BRANCH
0489446 colleague       Fri Apr 19 08:50:09 2024 +0000  commit message

There are 18 lines in this output. Therefore n=18.

Here is the output from git rebase -i HEAD~18.

pick 45c0d75 (me <[email protected]>) commit message
pick a519421 (me <[email protected]>) commit message
pick 5bb52cc (me <[email protected]>) commit message
pick 51f831a (me <[email protected]>) commit message
pick 530a6f3 (me <[email protected]>) commit message
pick 72c89c8 (me <[email protected]>) commit message
pick 59052f4 (me <[email protected]>) commit message
pick ce9faf9 (colleague <[email protected]>) commit message
pick e399c0a (colleague <[email protected]>) commit message
pick 82f29f0 (colleague <[email protected]>) commit message
pick 9c405ed (colleague <[email protected]>) commit message
pick a1f4893 (colleague <[email protected]>) commit message
pick b974516 (colleague <[email protected]>) commit message
pick 50d2394 (colleague <[email protected]>) commit message
pick 020e80c (colleague <[email protected]>) commit message
pick 09addd8 (colleague <[email protected]>) commit message
pick ef65821 (colleague <[email protected]>) commit message
pick ca4f3f7 (colleague <[email protected]>) commit message
pick e1098a7 (colleague <[email protected]>) commit message
pick 2275c59 (colleague <[email protected]>) commit message
pick c3614f2 (other-colleague <[email protected]>) commit message
pick 0e7fa78 (other-colleague <[email protected]>) commit message
pick b7ee582 (me <[email protected]>) commit message
pick 117178a (colleague <[email protected]>) commit message
pick 4f68792 (me <[email protected]>) commit message
pick 821a479 (me <[email protected]>) commit message
pick 6ea09f1 (me <[email protected]>) commit message
pick 0936af5 (me <[email protected]>) commit message
pick 6b43a34 (me <[email protected]>) commit message
pick 23a1f3e (me <[email protected]>) commit message
pick 9e907af (colleague <[email protected]>) commit message
pick 64c08cc (colleague <[email protected]>) commit message
pick 58e0601 (colleague <[email protected]>) commit message
pick 002c5e6 (colleague <[email protected]>) commit message
pick 17f71cb (colleague <[email protected]>) commit message
pick de2b3a6 (colleague <[email protected]>) commit message
pick 9a2bfb0 (colleague <[email protected]>) commit message
pick 94728d9 (colleague <[email protected]>) commit message # empty
pick 48f1190 (colleague <[email protected]>) commit message
pick 0489446 (colleague <[email protected]>) commit message
pick 06d62f2 (colleague <[email protected]>) commit message
pick 392e9c3 (me <[email protected]>) commit message
pick aed07ae (me <[email protected]>) commit message
pick a74b81a (colleague <[email protected]>) commit message
pick da11abe (colleague <[email protected]>) commit message
pick 374add4 (me <[email protected]>) commit message
pick 7b75da8 (colleague <[email protected]>) commit message
pick 998be63 (colleague <[email protected]>) commit message
pick 3e3f411 (me <[email protected]>) commit message
pick 130f00e (me <[email protected]>) commit message

# Rebase d0bea91..130f00e onto d0bea91 (50 commands)

This is clearly a lot more than 18 lines. In fact, it is a total of 50 lines.

Why does this happen? What is going on here? Clearly this method of rebasing doesn’t make much sense. So what should I be doing instead?