[clangd-dev] [monorepo] Much improved downstream zipping tool available

[David Greene via clangd-dev]

Björn Pettersson A <bjorn.a.pettersson at ericsson.com> writes:

>> Ok, in that case I would expect the resulting history to look like
>> this:
>> 
>>     UL4->UC2->UL3->UL2->UL1->UL0->UC1 <- monorepo/master
>>                          |         \
>>                          \          `---.
>>                           `------------. \
>>                                         \|
>>                             ... ->DL2->DL1/DC2 <- zip/master
>>                                         /
>>                             ... ->DC2--'
>> 
>
> I still do not understand how that actually works technically, but maybe
> it does if you say so. But I also believe that "git log" etc on DL1/DC2
> will show that commit UL0 is part of my tree (which it isn't?). This will
> be really confusing when looking back at the history when debugging etc.

Yes, it will look like UL0 is part of your tree.  The edge from
UL1->DL1, which looks redundant, is actually there as a visual reminder
of the state of the llvm tree.

Unfortunately, git just doesn't have a good way to express the kind of
history we're creating here.  Since redundant edges are oddball in git
and git itself never creates them, I thought it would be strange enough
to stick out as a reminder.

If there's some other way to express this (Git notes?  Commit message?)
that would be more helpful, I'd be happy to consider it.

                             -David