Bug#1081434: dpkg-source: should refuse to apply indented diffs, or at least give a warning

On Sat, 07 Feb 2026 at 01:15:02 +0100, Guillem Jover wrote:
>On Fri, 2026-02-06 at 13:22:51 +0000, Simon McVittie wrote:
>> I was reminded of this by an indented diff similar to my GTK example
>> accidentally getting into Debian's i3 package recently
>> (https://bugs.debian.org/1126992).

Having said that, I'm not sure whether what Tj proposed here would have 
avoided the i3 bug or not. In the GTK bug the part of the commit message 
that looked like a patch was indented and would not have been applied by 
`git am`, but in i3 it was unindented and in a Github-style fenced code 
block (``` before and after) which *would* have been applied by `git 
am`, and I'm not sure the format is strict enough to distinguish that 
from the actual patch content.

(Really this is a general problem with the patch format and in-band 
signalling, rather than anything specific to dpkg or git.)

     smcv