Is there an hg equivalent of `git stash save -p` that can split chunks into smaller chunks?

Question

I want to commit only some of the modifications I made to my files and my preferred way to do this is to shelve/stash away the changes I don't want to commit. This allows me to test the changes I will commit before actually commiting them.

The problem I am having is that when I use the "shelve" tool in tortoisehg I can't find any way to split a chunk into two smaller chunks. For example, I have a chunk that looks like this:

@@ -1,1 +1,2 @@
-hallo world
+hello world
+something else

I would like to shelve away the "something else" so I can commit just the "hallo->hello" fix. However, since tortoisehg is seeing this a single chunk I can either shelve both or none of the changes.

I also tried using the shelve extension via the command line but from what I understood from the documentation it does not offer the feature to shelve away only parts of the files.

Answer 1

You can accomplish your goal from the command line. There are interactive versions of hg commit, hg revert, and hg shelve, and they have low-level options to hack a patch together if needed; you can use them with the -i (or --interactive) command line option.

This means that you can build up a commit with hg commit -i and hg commit --amend -i. If you have the evolve extension installed, you can use hg uncommit to pull changes out of the commit again; if not, you can use hg revert -r .~1 or hg revert -i -r .~1 a file and use hg commit --amend -i again to fix it up.

In order to select individual lines from a patch, you have two options. You can use e to edit the patch (but see below for a more convenient option).

You can then use hg shelve to shelve the remaining changes.

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You can in principle also do this with hg shelve -i, however, there's a big caveat; if you edit patches for hg shelve -i, then Mercurial's merge mechanism will get confused and not process the change cleanly, but dump you in a merge tool in order to resolve this apparent conflict (which means lots of extra work to resolve it). Hence why I strongly recommend using hg commit -i and hg commit --amend -i if you want to manipulate things at the line level (hg shelve -i works fine if you don't edit the patches).

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For added convenience (that prevents you from editing patches), you can also enable the experimental crecord option by adding the following to your hgrc file:

[experimental]
crecord = true

This will enable a terminal-based hunk editor for hg commit -i, hg revert -i, and hg shelve -i that allows you to select individual lines and hunks (internally, that works roughly the same way as editing patches). Use the ? key to get help in that editor; use f to unfold/fold individual hunks and the space key to select hunks/lines.

Note that line-based selection for this tool in conjunction with hg shelve -i comes with the same caveats as editing patches; i.e. use hg commit -i and hg commit --amend -i instead if you want to do line-based selection. Also, line-based selection for hg revert -i will still revert the entire hunk. (There's a reason why this option is still marked as experimental.)