git combine two commit

Get back to where you started with

$ git rebase --abort

Say your history is

$ git log --pretty=onelinea931ac7c808e2471b22b5bd20f0cad046b1c5d0d cb76d157d507e819d7511132bdb5a80dd421d854f bdf239176e1a2ffac927d8b496ea00d5488481db5 a

That is, a was the first commit, then b, and finally c.

Running git rebase --interactive HEAD~2 gives you an editor with

pick b76d157 bpick a931ac7 c# Rebase df23917..a931ac7 onto df23917## Commands:#  p, pick = use commit#  r, reword = use commit, but edit the commit message#  e, edit = use commit, but stop for amending#  s, squash = use commit, but meld into previous commit#  f, fixup = like "squash", but discard this commit's log message## If you remove a line here THAT COMMIT WILL BE LOST.# However, if you remove everything, the rebase will be aborted.#

Changing b's pick to squash will result in the error you saw, but if instead you squash c into b by changing the text to

pick b76d157 bs a931ac7 c

and save-quitting your editor, you'll get another editor whose contents are

# This is a combination of 2 commits.# The first commit's message is:b# This is the 2nd commit message:c

When you save and quit, the contents of the edited file become commit message of the new combined commit:

$ git log --pretty=oneline18fd73d3ce748f2a58d1b566c03dd9dafe0b6b4f b and cdf239176e1a2ffac927d8b496ea00d5488481db5 a