Bug Report: Multi-line trailers containing empty lines break parsing

[Matthias Buehlmann <Matthias.Buehlmann@mabulous.com>]

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Please answer the following questions to help us understand your issue.

What did you do before the bug happened? (Steps to reproduce your issue)

    create a file containing multiline trailer:

    $ echo "Test" > test.txt
    $ git interpret-trailers --where end --if-exists addIfDifferent
--trailer "SingleLineTrailer: This is a single line trailer"
--in-place test.txt
    $ git interpret-trailers --where end --if-exists addIfDifferent
--trailer "MultiLineTrailer: This is"$'\n a folded multi-line\n
trailer' --in-place test.txt

    parse trailers:

    $ git interpret-trailers --parse test.txt
    SingleLineTrailer: This is a single line trailer
    MultiLineTrailer: This is a folded multi-line trailer

    (so far, all is as expected)

    now, adding multiline trailer containing empty line:

    $ git interpret-trailers --where end --if-exists addIfDifferent
--trailer "MultiLineTrailer: This is"$'\n a folded multi-line\n
trailer which\n \n contains an\n empty line' --in-place test.txt

    parse trailers again:

    $ git interpret-trailers --parse test.txt

What did you expect to happen? (Expected behavior)

I would expect the following output:

    $ git interpret-trailers --parse test.txt
    SingleLineTrailer: This is a single line trailer
    MultiLineTrailer: This is a folded multi-line trailer
    MultiLineTrailer: This is a folded multi-line trailer which
contains an empty line

What happened instead? (Actual behavior)

    no output is generated, but exit code is nevertheless 0:

    $ git interpret-trailers --parse test.txt
    $ echo $?
    0

What's different between what you expected and what actually happened?

    I would expect either to get an output or the call to exit non-zero

Anything else you want to add:

    According to my interpretation of the documentation of git
intepret-trailers, empty lines should be supported if properly folded,
in the same way as for example the PGP signature added to the commit
header contains a (properly folded) empty line

Please review the rest of the bug report below.
You can delete any lines you don't wish to share.


[System Info]
git version:
git version 2.30.0.windows.2
cpu: x86_64
built from commit: f8cbc844b81bf6b9e72178bbe891a86c8bf5e9e7
sizeof-long: 4
sizeof-size_t: 8
shell-path: /bin/sh
uname: Windows 10.0 18363
compiler info: gnuc: 10.2
libc info: no libc information available
$SHELL (typically, interactive shell): C:\Program Files\Git\usr\bin\bash.exe


[Enabled Hooks]
post-commit