Unselected lines may become hidden

[Adrian104]

Description of the Issue

Suppose that the content of the document alternates between visible individual lines and hidden blocks of text. In this situation, when the user tries to hide a single line, only that should become hidden. Instead, program hides all the lines that alternate between already hidden blocks of text.

Steps to Reproduce the Issue

Step 1. Copy and paste the following text in a new document:

Line 1
 Line 2    (hide)
  Line 3
   Line 4  (hide)
    Line 5
   Line 6  (hide)
  Line 7
 Line 8    (hide)
Line 9

Step 2. Hide labeled lines. It should look like this:

Step 3. Select only the line number 5 and hide it.

Expected Behavior

Line 1, 3, 7 and 9 should remain visible:

Actual Behavior

Only line 1 and 9 are visible:

Debug Information

Notepad++ v8.5.7   (64-bit)
Build time : Sep  6 2023 - 23:13:49
Path : C:\Program Files\Notepad++\notepad++.exe
Command Line : 
Admin mode : OFF
Local Conf mode : OFF
Cloud Config : OFF
OS Name : Windows 10 Home (64-bit)
OS Version : 22H2
OS Build : 19045.3448
Current ANSI codepage : 1252
Plugins : none

[alankilborn]

This joins a long list of issues about problems with hiding lines in Notepad++.