manifest: add optional base check on remove and extend

This adds an optional, built-in checker for
guarding against patches hanging on wrong
base revisions, which is useful if a lower layer of
the manifest changes after a patch was done.

When adding a patch with a new revision using
extend-project or remove-project/project:

          C---D---E patches in project bla
         /
    A---B project bla in manifest state 1

<extend-project name="bla" revision="E" base-rev="B">

If project bla gets updated, in a new snap ID
or by a supplier or similar, to a new state:

          C---D---E patches in project bla
         /
    A---B---F---G project bla in manifest state 2

Parsing will fail because revision of bla is now G,
giving the choice to create a new patch branch
from G and updating base-rev, or keeping previous
branch for some reason and only updating base-rev.

Intended for use in a layered manifest with
hashed revisions. Named refs like branches and tags
also work fine when comparing, but will be misleading
if a branch is used as base-rev.

Change-Id: Ic6211550a7d3cc9656057f6a2087c505b40cad2b
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/436777
Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Tested-by: Fredrik de Groot <fredrik.de.groot@haleytek.com>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>

0 files changed, 0 insertions, 0 deletions