Repository: vscode
Issue: Inconsistent behavior of diff line border
Labels: bug,diff-editor

Type: <b>Bug</b>

## Steps to reproduce:

1. use any theme that has `diffEditor.insertedTextBorder` and `diffEditor.removedTextBorder` item, or add that manually through the setting.
2. create a git folder, create a file and some changes, commit, up to a point where you can have a diff showing what have been inserted and removed
3. open the changed file in diff mode to see the changes
4. make the editor window/tab small enough so that instead of shown side-by-side, the changes are shown inline.

## Expected
the borders of removed line (red) should be shown to the whole line length, just like when in side-by-side mode, and like the borders of inserted line (green)

![image](https://github.com/microsoft/vscode/assets/146386738/c03ce35b-e4e4-4a45-acd9-52e2bdb31d9a)
_Default HC Dark Theme_

![image](https://github.com/microsoft/vscode/assets/146386738/35f7b431-3d14-4053-9bf8-d96c5a95ffbe)
_Wine Bar Monokai_

## Actual
the borders of removed line (red) are shown only to the length of the text. (I also noticed that every token has its own vertical border, but I am not sure if this is intentional. In any case, in the side-by-side mode and for the inserted text (green) this does not appear)

![image](https://github.com/microsoft/vscode/assets/146386738/18ca244d-10a3-4c02-9a00-7b5551d0d266)
_Default HC Dark Theme_

![image](https://github.com/microsoft/vscode/assets/146386738/a409fd4e-c301-4484-8477-4ccb17ab02b6)
_Wine Bar Monokai_

Personally I find that the actual result is not necessarily bad, but the inconsistency with the side-by-side mode and the border of the inserted lines is a bit bothering.

VS Code version: Code - Insiders 1.86.0-insider (feff7c8a7e1c82320380f42d898a1e03051fefb7, 2024-01-26T03:26:40.730Z)
OS version: Windows_NT x64 10.0.22631
Modes:

<details>
<summary>System Info</summary>

|Item|Value|
|---|---|
|CPUs|12th Gen Intel(R) Core(TM) i7-12700 (20 x 2112)|
|GPU Status|2d_canvas: enabled<br>canvas_oop_rasterization: enabled_on<br>direct_rendering_display_compositor: disabled_off_ok<br>gpu_compositing: enabled<br>multiple_raster_threads: enabled_on<br>opengl: enabled_on<br>rasterization: enabled<br>raw_draw: disabled_off_ok<br>skia_graphite: disabled_off<br>video_decode: enabled<br>video_encode: enabled<br>vulkan: disabled_off<br>webgl: enabled<br>webgl2: enabled<br>webgpu: enabled|
|Load (avg)|undefined|
|Memory (System)|63.75GB (45.79GB free)|
|Process Argv|--crash-reporter-id 62b05a90-6fdd-4775-8c40-a64511a0a91e|
|Screen Reader|no|
|VM|0%|
</details><details><summary>Extensions (3)</summary>

Extension|Author (truncated)|Version
---|---|---
vscode-pull-request-github|Git|0.79.2024012510
csharp|ms-|2.15.30
vscode-dotnet-runtime|ms-|2.0.1

(2 theme extensions excluded)

</details><details>
<summary>A/B Experiments</summary>

```
vsliv368cf:30146710
vspor879:30202332
vspor708:30202333
vspor363:30204092
vscod805:30301674
vsaa593:30376534
py29gd2263:30784851
c4g48928:30535728
vscrp:30624060
pythongtdpath:30726887
welcomedialog:30812478
pythonidxpt:30768918
pythonnoceb:30776497
asynctok:30898717
dsvsc013:30777762
dsvsc014:30777825
dsvsc015:30821418
pythontestfixt:30866404
pythonregdiag2:30926734
pyreplss1:30879911
pythonmypyd1:30859725
pythoncet0:30859736
pythontbext0:30879054
accentitlementst:30870582
dsvsc016:30879898
dsvsc017:30880771
dsvsc018:30880772
fegfb526:30945144
bg6jg535:30946824

```

</details>

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