git format patch limit?

Question

I am trying to cherry pick some commits in my repo but it keeps on failing.
(I tried this tutorial on SO: "What is the best way to git patch a subrange of a branch?")

So I did a workaround:

• just do a git format-patch of the commits
• and just delete the extra files.

Really dirty stuff, but a bit easier to do.
So I do a

git format-patch -66

(the commit I was looking for was 66 commits away)

Problem with this is it keeps stopping at 047.
What gives? Is there a limit to the patches I can generate?

Answer 1

The -<n> option of git format-patch is a bit tricky, as this thread illustrates, from git contributor (for gitweb) and SO user Jakub Narębski:

It looks like there is a conceptual bug in how git-format-patch works, namely that '-<n>' is passed to rev-list / log generating machinery, and it limits number of commits to consider;

if some of those commits are merge commits, which cannot be represented as patches, the number of patches it generates is less than specified <n> (as you can see in the example I have provided, where <n> == 3, and git-format-patch generated 2 patches, not 3).

In extreme case (like 'pu') it can generate no patch.

(pu being here the public branch of the git-scm repo.)

In the OP's case, as he points out in the comment, it could mean 19 commits that are merge patches.

---

Jakub goes on proposing the following solution:

Update git-format-patch documentation to say 'commits' instead of 'patches',
and perhaps also be loud about commits we are skipping, so that my example would look e.g. like this:

 $ git format-patch -3
 0001-gitweb-Prepare-for-splitting-gitweb.txt
 0002-gitweb-Create-Gitweb-Git-module.txt
 Skipping merge commit: Merge branch 'maint'

, to which Ramkumar Ramachandra proposes last August (2010) to write a patch.

You can see that patch simmering in this September 2010 what's cooking in git.git

[New Topics]

rr/format-patch-count-without-merges (2010-08-28) 2 commits
- format-patch: Don't go over merge commits
- t4014-format-patch: Call test_tick before committing

and is still in the latest what's cooking (Sept. 27th) in the [Cooking] section, with the following annotation:

Comments from potential users?