Re: [PATCH v3 2/2] apply: reload .gitattributes after patching it
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Aug 15, 2019, 22:10 UTC
- Message-ID
- <xmqqftm22i7e.fsf@gitster-ct.c.googlers.com>
- In-Reply-To
- <xmqq7e7h7xap.fsf@gitster-ct.c.googlers.com>
Junio C Hamano <gitster@pobox.com> writes:
Show 16 quoted lines
> "brian m. carlson" <sandals@crustytoothpaste.net> writes: > >> When applying multiple patches with git am, or when rebasing using the >> am backend, it's possible that one of our patches has updated a >> gitattributes file. Currently, we cache this information, so if a >> file in a subsequent patch has attributes applied, the file will be >> written out with the attributes in place as of the time we started the >> rebase or am operation, not with the attributes applied by the previous >> patch. This problem does not occur when using the -m or -i flags to >> rebase. > ... > "rebase -m" and "rebase -i" are not repeated run_command() calls > that invoke "git cherry-pick" or "git merge" these days, either, so > I am somewhat curious how they avoid fallilng into the same trap. > > Thanks for the fix. Will queue.
Actually there still is one more thing I wasn't clear about the change.
Show 6 quoted lines
> To ensure we write the correct data into the working tree, expire the > cache after each patch that touches a path ending in ".gitattributes". > ... > + if (!flush_attributes && patch->new_name && > + ends_with_path_components(patch->new_name, GITATTRIBUTES_FILE)) > + flush_attributes = 1;
When an attribute file is removed by a patch, we should forget what we read earlier from the file before it got removed. Would such a case, where patch->new_name would be NULL, be handled correctly?
The call to ends_with_path_components() is almost no cost, and I would suspect that this call is easier to reason about without the "!flush_attributes &&" in the conditional part, by the way.
Thanks.