Re: [PATCH 0/1] blame: Skip missing ignore-revs file

[Thranur Andul <thranur@gmail.com>]

On 07/08/2021 22:58, Junio C Hamano wrote:
> Noah Pendleton <noah.pendleton@gmail.com> writes:
> 
> 
> That cuts both ways, though.  Failing upon missing configuration
> file is a way to catch misconfiguration that is hard to diagnose.
> 
> I wonder if we can easily learn where the configuration variable
> came from in the codepath that diagnoses it as a misconfiguration.
> 
> If it came from a per-repo configuration and names a non-existent
> file, it clearly is a misconfiguration that we want to flag as an
> error.  Even if it came from a per-user configuration, if it was
> specified in a conditionally included file, it is likely to be a
> misconfiguration.  If it came from a per-user configuration that
> applies without any condition, it can be a good convenience feature
> to silently (or with a warning) ignore missing file.
>
I am very interested in this feature, but I'd like to add another point 
to the discussion: in the case of ignoreRevsFile in particular, no one 
creates a repository with such a file; it is always added later. 
However, when bisecting (a typical usage scenario for git-blame), we may 
end up returning back to a point _before_ the file had been added, and 
then, git-blame fails. This often happens to me, and I am then forced to 
`touch` the file to create it again, only to ensure git-blame keeps 
working. And then, when I want to return to the HEAD commit, the file 
must be erased again otherwise there is a conflict. So, for me, the 
"ignore if absent" behavior seems to me like it should be the default.