build-pkgs --edit should use git am to apply patches

[Jim Somerville]

Brief Description
-----------------

When using build-pkgs --edit, patches are applied by the tool to the source using "patch -p1 ....", and then committed using a horrible shortlog, and any long log commit header entries are completely lost. This makes build-pkgs --edit almost completely useless to anybody looking to modify existing patches. I consider this lack of utility to be a bug. We've been living with this for far too long now.

build-pkgs --edit should first try to apply patches via "git am", and failing that then fallback to "patch -p1 ...." as there are some non git formatted patches in some of our packages (would be nice to find them and get a commit header onto them). Or maybe better yet, first check to see if the patch has a git commit header on it and if so, then use git am to apply it.

Severity
--------
Major: System/Feature is usable but degraded

Steps to Reproduce
------------------

build-pkgs --edit kernel (or other package that we build that has patches against it)

Expected Behavior
------------------

You get a source repo containing commits with the commit headers preserved from the patches.

Actual Behavior
----------------

You get a source repo containing commits with munged headers.

Reproducibility
---------------

100%

System Configuration
--------------------

N/A it's in the build tool

Branch/Pull Time/Commit
-----------------------

It has been like this from day one.

Last Pass
---------

N/A

Timestamp/Logs
--------------

N/A

Test Activity
-------------

N/A

Workaround
----------

Hard reset the repos and apply the patch sequences manually via git am

[Ghada Khalil (gkhalil)]

Assigning to the stx.build PL for triage/follow-up

[Ghada Khalil (gkhalil)]

As per Frank Miller, this is a would-be-nice, but not considered gating any specific stx release.

[Frank Miller (sensfan22)]

The build SMEs agreed that this would be a good idea to address - not sure yet when this can be looked at.