bug report: "git pack-redundant --all" crash in minimize()

Hello,

I'm getting the following crash from "git pack-redundant --all" (output from valgrind):

==14070== Invalid read of size 8 ==14070== at 0x18F165: minimize (pack-redundant.c:399) ==14070== by 0x18F165: cmd_pack_redundant (pack-redundant.c:622) ==14070== by 0x1242D3: run_builtin (git.c:444) ==14070== by 0x1242D3: handle_builtin (git.c:674) ==14070== by 0x125393: run_argv (git.c:741) ==14070== by 0x125393: cmd_main (git.c:872) ==14070== by 0x123E7D: main (common-main.c:52) ==14070== Address 0x10 is not stack'd, malloc'd or (recently) free'd

Commands to reproduce:

mkdir new cd new git init touch foo.txt git add foo.txt git commit -m "first commit" git gc git pack-redundant --all

The same happens with Ubuntu's git 2.25.1 as well as manually compiled git 2.30.0.rc0 from current master.

The reason this showed up is that Yocto's build tool, bitbake, sometimes invokes this git command on some of the repositories it downloaded. This issue was apparently also reported here: https://bugzilla.redhat.com/show_bug.cgi?id=1803506

Kind Regards, Daniel