[scintilla:bugs] #2497 Rectangular selection indent incorrect selection modes and positions

[Michael Heath]

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[bugs:#2497] Rectangular selection indent incorrect selection modes and positions

Status: open
Group: Bug
Labels: scintilla
Created: Thu Jan 08, 2026 02:02 AM UTC by Michael Heath
Last Updated: Thu Jan 08, 2026 02:02 AM UTC
Owner: nobody
Attachments:

• scintillaRectIndentUpDown.zip (80.7 kB; application/x-zip-compressed)

• Windows 11

• ScITE: 5.5.8 Scintilla: 5.5.8 Lexilla: 5.4.6

The issue is based on:

BUG Incorrect tab behavior in column mode

caused by a change-set committed at

Remove unnecessary InvalidateStyleRedraw() for Message::SetUseTabs

Symptoms:

• Carets can move to incorrect positions.
• Undo changes selection mode so Redo is different.

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Note: Preview of code converts tabs to spaces. I expect the results to remain the same.

1. Test start of rectangle at column 0:

-
    -

1. Rectangle select downwards and tab to indent result

    |-
    |   -

The pipe character represent the carets.
The change-set sets a thin selection.

1. Reset to step 1. Rectangle select upwards and tab to indent result.

    -|
        |-

The 1st caret is 1 position too far.

Another symptom from the change-set is undo reverts the selection mode to stream mode as the indenting was done with stream mode. So undo and redo does this with the select downwards continuing with step 2.

    |-
        |-

The undo seems to forget the rectangle mode and remembers the stream mode so the result is different.

I have attached possible fix. I tested the IDM_HELP code in SciTE and it seems to pass OK.

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