Re: [BUG] "git log" command wraps lines not correctly while terminal width changed

From: Jeff King <peff@peff.net>
Date: Jul 29, 2022, 20:41 UTC
Message-ID: <YuRF7rSskqT2YkMs@coredump.intra.peff.net>
In-Reply-To: <CAFRNrRYs5tkTq_Dz3qX+jZ_PJLdUwT4NgabavYeHsGOEtMTq5w@mail.gmail.com>

On Fri, Jul 29, 2022 at 06:35:20PM +0400, Sergey Grunenko wrote:

> Hi, developers. I met some small bug in console report of "git log" command

I don't think this is a bug in git, because git isn't actually doing any wrapping.

Show 6 quoted lines

> How to reproduce:
> 1. Open terminal
> 2. go to existing repository with some branches
> 3. Change terminal width to 50 characters (or less, to be sure, that
> first line wraps)
> 4. process command "git log --graph" and be sure, that a few lines is wrapping

In your example here, any line breaking is not done by "git log", but either by the pager ("less", by default) or by the terminal.

> 5. Increase terminal width until line breaks stop
> 6. Lines wrapping is changing and is correct

OK, so it sounds like you're probably seeing "less" get told by the terminal that the window size has changed, and it adapts.

Show 7 quoted lines

> 7. Click <up> <down> buttons or rotate mouse scroll to scroll text two
> screens next and back
> Incorrect behavior:
> 8. You'll see that the wrapping behavior is like terminal width didn't changed.
> 9. But if you touch the terminal width again, wrapping will be correct
> Awaited behavior:
> 8a. Lines wrapping is like terminal has changed value

The mouse scroll wheel is presumably telling the terminal to move through its back-scroll. How it handles re-rendering of content that's only in the back-scroll is up to it, and totally outside the control of either git or the pager. It behaves as your 8a for me, using urxvt on Linux. You probably need to file a report with the provider of your terminal emulator.

-Peff