Re: Trimming 'deadheads' (TREESAME 2nd parent) from revision walks?

Hi Philip,

On Sat, 18 Sep 2021, Philip Oakley wrote:

Yes, there is, but it is not as easy as a command-line option: `git replace`.

For example, to pretend that the most recent merging-rebase in Git for Windows was (almost) a regular rebase, you replace the "Start the merging-rebase" commit with a graft that only keeps its first parent:

	git replace --graft HEAD^{/^Start.the} HEAD^{/^Start.the}^

(Of course, you still have to find out the first-parent-treesame merge commits that you want to replace.)

If you want to do that only temporarily, you can use a throw-away namespace instead of the refs/replace/ one:

	export GIT_REPLACE_REF_BASE=refs/philipoakley/
	git replace --graft HEAD^{/^Start.the} HEAD^{/^Start.the}^

Before:

	[...]
	| > | | 23e09ef1080 Merge 'remote-hg-prerequisites' into HEAD
	|/| | |
	| > | | 0221569db1c Always auto-gc after calling a fast-import transport
	| > | | f189282dcfc remote-helper: check helper status after import/export
	| > | | 158907ceb87 transport-helper: add trailing --
	| > | | 6e34e54050c t9350: point out that refs are not updated correctly
	|/ / /
	> | |   7b2b910b080 Start the merging-rebase to v2.33.0
	|\ \ \
	| |_|/
	|/| |
	| > |   508bb26ff90 (tag: v2.33.0-rc2.windows.1) Merge pull request #3349 from vdye/feature/ci-subtree-tests
	[...]

After:

	[...]
	| > | | 23e09ef1080 Merge 'remote-hg-prerequisites' into HEAD
	|/| | |
	| > | | 0221569db1c Always auto-gc after calling a fast-import transport
	| > | | f189282dcfc remote-helper: check helper status after import/export
	| > | | 158907ceb87 transport-helper: add trailing --
	| > | | 6e34e54050c t9350: point out that refs are not updated correctly
	|/ / /
	> | / 7b2b910b080 (replaced) Start the merging-rebase to v2.33.0
	| |/
	|/|
	> | 225bc32a989 (tag: v2.33.0, upstream/maint, mirucam/maint, gitgitgadget/snap, gitgitgadget/maint) Git 2.33
	[...]

You can always clean up _all_ replace objects via `git replace -d $(git replace -l)`.

Ciao, Dscho