Multi-Line Oh-My-Posh config produces additional lines after clink update

[rainerzufalldererste]

A recent clink update appears to have broken the multi-line behavior of my oh-my-posh config.

What it used to look like

What's happening now

Usually, the interface updates after a second or two, but prints another instance of the first segment in the meantime.

I'm currently on

• Clink v1.7.16.988e1c
• oh-my-posh v25.20.0

Although this behavioural change was introduced with a clink update, please let me know if it it somehow related to a bug in oh-my-posh (or my oh-my-posh config).

Thanks!

[chrisant996]

There are some strange things going on.

The fact that your customization somehow erases the left aligned part of the prompt even when prompt.transient is off means there was already something wrong back when you thought it was working fine.

It should have been looking like this:

I see what change in Clink is triggering the changed behavior in v1.7.15, but it doesn't appear to be the root cause of the problem. Because it was already not displaying things correctly to begin with, even when you felt that it was.

I can't tell yet whether the root cause is an issue in Clink, or in oh-my-posh, or in your config.

[chrisant996]

I noticed a cosmetic bug in your config:

The \uf00c is missing a space after it, so the icon gets cut off.

UPDATE: Oh, never mind about this part. You are using mono-width nerd font icons, and I was testing in window that was using full-width nerd font icons. Presumably the extra space after the \uf00d is a preference thing to keep the tips of the "X" from seeming close to the edge of the rounded end cap.

         {
           "properties": {
             "always_enabled": true,
             "display_exit_code": true
           },
           "trailing_diamond": "\ue0b4",
-          "template": " {{ if gt .Code 0 }}\uf00d {{ reason .Code }}{{ else }}\uf00c{{ end }}",
+          "template": " {{ if gt .Code 0 }}\uf00d {{ reason .Code }}{{ else }}\uf00c {{ end }}",
           "foreground": "#7f7f7f",
           "background": "#252525",
           "type": "status",
           "style": "diamond",
           "foreground_templates": [
             "{{ if gt .Code 0 }}#ffffff{{ end }}"
           ],
           "background_templates": [
             "{{ if gt .Code 0 }}#ff3863{{ end }}"
           ]
         }

[chrisant996]

Aha, and making the following change in the config seems to eliminate all of the problems:

But that change shouldn't be necessary. So, I think the root cause is likely to be a bug in Clink somewhere. I'll investigate more later and track down the root cause.

         {
           "properties": {
             "always_enabled": true,
             "display_exit_code": true
           },
-          "trailing_diamond": "\ue0b4",
+          "trailing_diamond": "\ue0b4\n",
           "template": " {{ if gt .Code 0 }}\uf00d {{ reason .Code }}{{ else }}\uf00c {{ end }}",
           "foreground": "#7f7f7f",
           "background": "#252525",
           "type": "status",
           "style": "diamond",
           "foreground_templates": [
             "{{ if gt .Code 0 }}#ffffff{{ end }}"
           ],
           "background_templates": [
             "{{ if gt .Code 0 }}#ff3863{{ end }}"
           ]
         }

[chrisant996]

I found the root cause.

Readline had a bug in a special case in its display code.

A while back I did the big rewrite to replace Readline's display code to fix a large collection of display bugs. This bug is one of the ones I fixed.

But the fix was slightly incorrect, and in a specific case it ended up mistakenly trying to compensate for something. The specific case is: a multi-line prompt which relies on wrapping and has no line breaks anywhere in it. Which your prompt config produces.

The next update for Clink will include a fix.

[rainerzufalldererste]

Hi @chrisant996

Thanks for your effort investigating this minor behavioral inconsistency so quickly, even though it first looked like it was being caused by a bug in my oh-my-posh config.

Very much appreciated! ♥

[chrisant996]

You're welcome, and thanks for reporting it!

Also, the reason the previous prompt always show up temporarily after running a command is because of how oh-my-posh works. Its Lua script remembers the old prompt and shows it temporarily while running a new oh-my-posh program instance in the background to generate a new prompt. Once the prompt is ready, then it gives the new prompt to Clink and the prompt gets refreshed.

The benefit of that approach is that the input line is responsive immediately (after the previous command finishes) without any delay waiting for a new prompt to be generated. It's what lets you hold Enter down and the new input lines show up without any delay, but at the expense of showing the previous prompt in the meantime.

Prompts that are written completely in Lua are able to be more granular about which parts of the prompt come from the previous prompt versus which parts are generated fresh. But oh-my-posh is a separate executable program, which isn't conducive for that.
That's why the other custom prompts show a mostly-updated prompt after each command, and only the git status portion of the prompt carries over from the previous prompt.

This is why, for example, you'll sometimes briefly see an "ERROR" indicator leftover from a previous prompt, and then it'll disappear a moment later.