From: code@xxxxxxxxxxxxxxx We did `git rebase --rebase-merges` on a branch with merge commits. Including back merges. The reflog after that showed some weird symbols for certain merge commits (only merges): e9c962f2ea0 HEAD@{8}: <binary>�: Merged in <branch> (pull request #4441) Some merge commits were normal. No backmerges were affected. We have a main branch. This other branch was created from the main branch. It had been kept up to date with backmerges. Then someone did a rebase on it once it was supposed to go into the main branch soonish. It looks like the string is uninit. The values are different each time. § Bisection Bisects to d188a60d722 (sequencer: stop exporting GIT_REFLOG_ACTION, 2022-11-09). § Reproduction on latest code Reproduced on `master`, on f65182a99e5 (The ninth batch, 2025-04-24). § Gdb This is the backtrace when I get the apparently uninit. string: ``` #0 run_git_commit (defmsg=0x555555babe70 "<repo path>/MERGE_MSG", opts=0x7fffffffc070, flags=0) at sequencer.c:1158 #1 0x00005555558740d9 in do_merge (r=0x555555a67020 <the_repo>, commit=0x555555b75cb0, arg=0x555555b2164d "<branch stuff> # Merged in <branch> { (pull request #4464)\nlabel branch-point-9\npick 4026b5ced849724bd3857283b6ad50c8609b6d33 only sh"..., arg_len=125, flags=0, check_todo=0x7fffffffb1e0, opts=0x7fffffffc070) at sequencer.c:4380 #2 0x0000555555876629 in pick_commits (r=0x555555a67020 <the_repo>, todo_list=0x7fffffffbf50, opts=0x7fffffffc070) at sequencer.c:5048 #3 0x0000555555877eeb in sequencer_continue (r=0x555555a67020 <the_repo>, opts=0x7fffffffc070) at sequencer.c:5480 #4 0x000055555563a491 in run_sequencer_rebase (opts=0x7fffffffc330) at builtin/rebase.c:369 #5 0x000055555563bc74 in run_specific_rebase (opts=0x7fffffffc330) at builtin/rebase.c:746 #6 0x000055555563fe2a in cmd_rebase (argc=0, argv=0x555555a73890, prefix=0x0, repo=0x555555a67020 <the_repo>) at builtin/rebase.c:1878 #7 0x0000555555574c0d in run_builtin (p=0x555555a34908 <commands+2280>, argc=2, argv=0x555555a73890, repo=0x555555a67020 <the_repo>) at git.c:480 #8 0x00005555555750ca in handle_builtin (args=0x7fffffffd8a0) at git.c:743 #9 0x000055555557538c in run_argv (args=0x7fffffffd8a0) at git.c:810 #10 0x00005555555759e2 in cmd_main (argc=2, argv=0x7fffffffda30) at git.c:950 #11 0x000055555569b0c3 in main (argc=5, argv=0x7fffffffda18) at common-main.c:9 ``` § No reproduction script I was unable to reproduce with a simple repo. setup. I tried: 1. Creating a side branch which had a merge 2. The side branch conflicted with the other branch 3. Rebased with `--rebase-merges` ----- Normal bugreport questionaire follows. ----- Thank you for filling out a Git bug report! Please answer the following questions to help us understand your issue. What did you do before the bug happened? (Steps to reproduce your issue) `git rebase --rebase-merges` on a branch with merge commits. Including back merges. What did you expect to happen? (Expected behavior) Normal “action” string for the reflog like for example `continue`: 3f90f6ab14d (HEAD -> <branch>) HEAD@{1}: rebase (continue): Merged in <branch> (pull request #4507) What happened instead? (Actual behavior) The “action” (or whatever it is) string is arbitrary bytes. Like some uninit. memory. ``` e9c962f2ea0 HEAD@{8}: <binary>�: Merged in <branch> (pull request #4441) ``` What's different between what you expected and what actually happened? Apparently uninit. string. Anything else you want to add: 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 2.49.0.459.gf65182a99e5 cpu: x86_64 built from commit: f65182a99e545d2f2bc22e6c1c2da192133b16a3 sizeof-long: 8 sizeof-size_t: 8 shell-path: /bin/sh libcurl: 7.81.0 OpenSSL: OpenSSL 3.0.2 15 Mar 2022 zlib: 1.2.11 SHA-1: SHA1_DC SHA-256: SHA256_BLK uname: Linux 6.8.0-58-generic #60~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Fri Mar 28 16:09:21 UTC 2 x86_64 compiler info: gnuc: 11.4 libc info: glibc: 2.35 $SHELL (typically, interactive shell): /bin/bash [Enabled Hooks]