Jupyter Notebook output renderer stucks preprocessing raw strings

[Marucmp]

Type: Bug

1. Create a new Jupyter Notebook file with raw string, containing a lot (12+) of escape charachters, like r"\a\c\e\f\g\h\i\k\l\m\n\o"
2. Throw some exception or error outside try/except block (which works fine as well as showing variable itself) within a cell with raw string, e.g.

raw_str = r"\a\c\e\f\g\h\i\k\l\m\n\o"
1/0

3. Time for error message rendering is too high and depends on a string length (feels like exponential). 12-13 symbols is enough to "Window is not responding" pop-up to appear.

4. Even with disabled extensions just reopening Notebook file without running any cells results in a renderer behaving incorrectly (it takes long time for it to show outputs)

VS Code version: Code 1.101.1 (18e3a1e, 2025-06-18T13:35:12.605Z)
OS version: Windows_NT x64 10.0.19045
Modes:

System Info

Item	Value
CPUs	Intel(R) Xeon(R) E-2176M CPU @ 2.70GHz (12 x 2712)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: enabled_on direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	63.79GB (52.23GB free)
Process Argv
Screen Reader	no
VM	0%

Extensions disabled

[Marucmp]

Impossible to attach .ipynb files, so cells within it may be the following.

# any number of characters (doesn't break Electron output)
raw_str = r"\a\c\e\f\g\h\i\k\l\m\n\o\p\q"
raw_str

# try/except block works fine as well
raw_str = r"\a\c\e\f\g\h\i\k\l\m\n\o\p\q"
try:
    1/0
except ZeroDivisionError as e:
    print(e)

# exception cause Electron to process output exponentially according to
# symbols count in a raw string (12 - too long, 13 - VSCode "Window is not responding" pop-up)
raw_str = r"\a\c\e\f\g\h\i\k\l\m\n\o"
1/0

[paultiq]

Is this same as #251731? Behavior is what I'm seeing on 1.101, but not on 1.100

[Marucmp]

Is this same as #251731? Behavior is what I'm seeing on 1.101, but not on 1.100

Seems so. But I probably figured out the cause. And it is easy to reproduce.
I've just updated my VSCode to 1.101 version and IDE started to freeze while it keeps my notebook opened.
It takes me some to to realize that it was the one specific cell with long raw file path in it.