Christian Couder [off-list ref] writes:
But if all the objects that point to an object, called O, are to be
replaced, then in most cases object O probably doesn't need to be
replaced. It's probably sufficient to create the new object, called
O2, that would replace object O and to replace all the objects
pointing to object O with objects pointing to O2.
Hmmmm.
What the above says, with "probably" and "most cases", can easily
inferred by anybody remotely intelligent, and the only reason to
have something like the above paragraph would be if it assures that
the statement holds without these qualifications to weaken it, which
it doesn't. I am not sure this paragraph adds much value.
The only case where someone might really want to replace object 0,
with an object O2 of a different type, and all the objects pointing to
it, is if it's really important, perhaps for external reasons, to have
object O's SHA1 point to O2.
The same comment applies here.
And anyway, if one really wants to do that, it can still be done using
"git update-ref".
And I really do not think this sentence is right---you can justify
with the same sentence to remove "git replace" wrapper.
The earlier suggestion to bypass the new hand-holding with "--force"
is more sensible, I think.
From: Junio C Hamano <redacted>
Christian Couder [off-list ref] writes:
quoted
But if all the objects that point to an object, called O, are to be
replaced, then in most cases object O probably doesn't need to be
replaced. It's probably sufficient to create the new object, called
O2, that would replace object O and to replace all the objects
pointing to object O with objects pointing to O2.
Hmmmm.
What the above says, with "probably" and "most cases", can easily
inferred by anybody remotely intelligent, and the only reason to
have something like the above paragraph would be if it assures that
the statement holds without these qualifications to weaken it, which
it doesn't. I am not sure this paragraph adds much value.
quoted
The only case where someone might really want to replace object 0,
with an object O2 of a different type, and all the objects pointing to
it, is if it's really important, perhaps for external reasons, to have
object O's SHA1 point to O2.
The same comment applies here.
quoted
And anyway, if one really wants to do that, it can still be done using
"git update-ref".
And I really do not think this sentence is right---you can justify
with the same sentence to remove "git replace" wrapper.
Ok, so the commit message (excluding the Acked-by and Signed-off-by)
will be only:
------------------------------------------
Users replacing an object with one of a different type were not
prevented to do so, even if it was obvious, and stated in the doc,
that bad things would result from doing that.
To avoid mistakes, it is better to just forbid that though.
If one object is replaced with one of a different type, the only way
to keep the history valid is to also replace all the other objects
that point to the replaced object. That's because:
* Annotated tags contain the type of the tagged object.
* The tree/parent lines in commits must be a tree and commits, resp.
* The object types referred to by trees are specified in the 'mode'
field:
100644 and 100755 blob
160000 commit
040000 tree
(these are the only valid modes)
* Blobs don't point at anything.
The doc will be updated in a later patch.
------------------------------------------
The earlier suggestion to bypass the new hand-holding with "--force"
is more sensible, I think.
There is already a --force option, but I can add a --force-type in a
another patch.
Thanks,
Christian.