Hey!

That's my first bug report for git and my first email to a mailing
list in general, I hope for understanding :)

[Steps to reproduce your issue]

Global .gitattributes:

*.txt diff=test

Global .gitconfig:

[diff "test"]
    textconv = cat
    cachetextconv = true

Called command:

git --no-pager diff --no-index foo.txt bar.txt

[Expected behavior]

diff --git a/foo.txt b/bar.txt
index f6a4b70..2b24d27 100644
--- a/foo.txt
+++ b/bar.txt

@@ -1 +1 @@
-Foo bar baz
+Foo bar qux

[Actual behavior]

BUG: refs.c:2095: attempting to get main_ref_store outside of repository

The command works as expected if cachetextconv is disabled:

git --no-pager -c diff.test.cachetextconv=false diff --no-index foo.txt bar.txt

[System Info]
git version 2.44.0.windows.1
cpu: x86_64
built from commit: ad0bbfffa543db6979717be96df630d3e5741331
sizeof-long: 4
sizeof-size_t: 8
shell-path: /bin/sh
feature: fsmonitor--daemon
uname: Windows 10.0 19045
compiler info: gnuc: 13.2
libc info: no libc information available
$SHELL (typically, interactive shell): C:\Program Files\Git\usr\bin\bash.exe

[Enabled Hooks]
not run from a git repository - no hooks to show

Pawel