Re: [Outreachy PATCH 1/2] apply: do not keep names from an unused "diff --git" line

[Phillip Wood <phillip.wood123@gmail.com>]

Hi Tanga

On 09/11/2026 13:13, Tanga Joris wrote:
> On Mon, 9 Nov 2026 at 13:52, Phillip Wood <phillip.wood123@gmail.com> wrote:

It would have been helpful to retain a bit more context here, I've 
restored it so anyone reading this could see the patch that I was 
referring to.

>>> diff --git a/f b/f
>>> 
>>> new file mode 100644
>>> index 0000000..d00491f
>>> --- /dev/null
>>> +++ b/f
>>> @@ -0,0 +1 @@
>>> +1 

>> To me this looks like a corrupt patch because we have a blank line after
>> the "diff --git" header followed by valid extended diff headers. Now
>> that we accept this do we respect the file mode?
> 
> No, it does not respect the file mode. "new file mode 100755" is
> ignored and the file gets the default mode.

So that is a good reason to reject this, rather than silently applying a 
corrupt patch.

 >>> diff --git a/f b/f
 >>> diff --git a/g b/g

>> This is the only one that I think it is reasonable to accept - we have
>> an empty patch for "f" followed by a valid patch for "g"
> 
> Alright, I will keep accepting this one.

Do we accept that now, or only with your patch?

> For the next version, I plan to die with an error when a "diff --git"
> line has no header lines after it, and a "---" and "+++" patch follows
> before the next "diff --git" line. The error would name the line of
> the "diff --git". An empty section followed by another "diff --git"
> line would still be ignored.
> 
> One thing I would like to check with you. On master, a blank line
> after "diff --git" is accepted in a patch that modifies a file. If
> that patch has "old mode" and "new mode" lines, the mode change is
> lost. The rule above would reject these patches too. What is your view
> on this?
Oh, so

diff --git a/f b/f

index 573541a..d00491f 100644
--- a/f
+++ b/f
@@ -1 +1 @@
-0
+1

applies. That looks like a corrupt patch as well to me and if we're 
ignoring the mode headers I'd say it is definitely a bug and rejecting 
it is the right thing to do.

Thanks

Phillip