`diff-hl-flydiff-mode` with `diff-hl-amend-mode` shifts highlights three lines up

[saolaolsson]

When enabling diff-hl-mode (20260328.1925, minimal config, git) and setting diff-hl-reference-revision to "HEAD^" (or using diff-hl-amend-mode):

diff-hl-flydiff-mode disabled: Correct highlights are shown.
diff-hl-flydiff-mode enabled: Correct highlights are shown but all are shifted three lines up.

[dgutov]

Hi! I haven't been able to reproduce this yet.

Could you show some example with a file and a couple of diffs? Or a test repo. But I could take the file, apply the diff, commit, apply the second one and see how the highlights differ with/without diff-hl-flydiff-mode.

[dgutov]

Perhaps include your Emacs version as well.

[saolaolsson]

I've tested it on 29.3 (official Ubuntu 24) and 30.1 (self-built) on one system and the problem is still present. I've now also tested it on 30.1 on a current Debian on a DIFFERENT system and the problem is NOT present there, but I don't see why this is so.

Do you have a suggestion on how I can debug this further? What would cause the highlighted lines to be shifted?

[dgutov]

Perhaps the difference is in the contents of the files? Or in the line endings different between the two repositories on the systems with 30.1? Are you testing with the same file with the same changes in it? You could try comparing the outputs of M-x diff between them, paying attention to the numbers in the hunk headers as well.

…

On Fri, Apr 24, 2026, at 2:44 PM, Ola Olsson wrote: *saolaolsson* left a comment (dgutov/diff-hl#274) <#274 (comment)> I've tested it on 29.3 (official Ubuntu 24) and 30.1 (self-built) on one system and the problem is still present. I've now also tested it on 30.1 on a current Debian on a DIFFERENT system and the problem is NOT present there, but I don't see why this is so. Do you have a suggestion on how I can debug this further? What would cause the highlighted lines to be shifted? — Reply to this email directly, view it on GitHub <#274 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AACCMBLNGP434EWPG2Q73G34XNOTHAVCNFSM6AAAAACX5GTPPCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DGMJTGIZTINZRHE>. Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/AACCMBP3W2ZVNVWPMBZ62DT4XNOTHA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIMZRGMZDGNBXGE42M4TFMFZW63VHMNXW23LFNZ2KKZLWMVXHJKTGN5XXIZLSL5UW64Y> and Android <https://github.com/notifications/mobile/android/AACCMBN52ETW7HTARZ53QAL4XNOTHA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIMZRGMZDGNBXGE42M4TFMFZW63VHMNXW23LFNZ2KKZLWMVXHJLTGN5XXIZLSL5QW4ZDSN5UWI>. Download it today! You are receiving this because you commented.Message ID: ***@***.***>