QuickLook takes a huge memory when previewing a txt file

[sharpchen]

Describe the bug
Same as title

To Reproduce
Steps to reproduce the behavior:

1. Previewing a txt file, its size is about 64KB. It's a metadata file of a landsat image.
2. Scroll down, then the program freeze.
3. Go to monitor, it took about 6600MB of memory as displayed

Desktop (please complete the following information):

• OS Version: [Windows 10 21H2]
• QuickLook Version: [v3.7.3 UWP from Windows Store]

Screenshots and Exception Log

Last line of this text is as the picture showed, it's gray colored, doesn't like normal content.
I have no idea what it is.
It just duplicates <0x00> for many times and I can't even copy the content.

I've checked the log, no exception recorded for this issue.

[xupefei]

Mind uploading the file to this issue?

[sharpchen]

Mind uploading the file to this issue?
L71119042_04220010304_MTL.txt

[xupefei]

This file do have A LOT of NULLs at the end:

The number of NULLs are so many such that it hit the performance limit of AvalonEdit: icsharpcode/AvalonEdit#376. I consider this an upstream issue.

Back to your problem - I suggest to investigate which application produced those NULLs at the end of the file. I saw those "filling bytes" in binary files, but never in plain texts.