[OE-core] using devtool for rebasing patches

[Paul Eggleton]

Hi Alex,

On Thu, 03 Nov 2016 18:01:27 Alexander Kanavin wrote:
> it would be very useful if devtool offered support for rebasing source
> patches when they fail to apply, but currently there does not seem to be
> any such feature:
> 
> ak at kanavin-desktop:~/development/poky/build$ devtool modify libksba
> Parsing recipes..done.
> NOTE: Fetching libksba...
> NOTE: Unpacking...
> NOTE: Patching...
> ERROR: Applying 'ksba-add-pkgconfig-support.patch' failed:
> checking file Makefile.am
> Hunk #1 FAILED at 21.
> 1 out of 1 hunk FAILED
> checking file configure.ac
> Hunk #1 succeeded at 414 (offset 14 lines).
> checking file ksba.pc.in
> checking file src/ksba.m4
> ERROR: Function failed: patch_do_patch
> ak at kanavin-desktop:~/development/poky/build$
> 
> What devtool could do here is apply the patches that can be applied and
> then partially apply the patches that fail. Then give the developer some
> kind of UI for dealing with the rejected hunks (which typically means
> finding the place in the target file where the changes should go and
> then manually editing them in, while looking at the original patch).
> 
> Without this feature devtool is half as useful as it could be
> particularly for recipe version updates.

"devtool upgrade" is designed specifically to handle the upgrade case and 
tries to rebase the old patches onto the new version, putting you into 
resolution mode with "git am" if it fails to apply a patch. I appreciate that 
you may now be working through sorting out all of the patches to reduce the 
fuzziness when applying, and that won't help in that scenario, but it would 
definitely be worth considering for upgrades.

I'm open to implementing better support for handling patch application failure 
for devtool modify - in fact there is a bug open for just that:

  https://bugzilla.yoctoproject.org/show_bug.cgi?id=8325

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre