Marks position after line delete / insert

[jacek-mulawka]

Probably a mark indicate a wrong line number after delete or insert a line.

The scenarios are:
add a mark (e.g. Ctrl + Shift + 1) somewhere in the middle lines (let say there are 10 lines at the document and I add a mark at the line 4) and

variant A - go to the end of the marked line (e.g. press End) and press Enter; the document have a new line and the mark moved to the line number 5 but I expect the mark stay at the line number 4 (to press Backspace or Delete move the mark again up).

variant B - go to the end of the marked line (e.g. press End) and press Delete; the document lost a line and the mark moved to the line number 3 but I expect the mark stay at the line number 4 (to press Enter move the mark again down).

variant C - go one line down (e.g. press Down Arrow) and press Enter; the document have a new line and the mark moved to the line number 5 but I expect the mark stay at the line number 4 (to press Backspace move the mark again up).

I am not sure whether marks should shift this way?

Probably the solution is to change the file SynEdit.pas. In procedures:

TCustomSynEdit.DoLinesDeleted
there is:
if Mark.Line >= FirstLine + Count then
Mark.Line := Mark.Line - Count
else if Mark.Line > FirstLine then
Mark.Line := FirstLine;

should be:
if Mark.Line > FirstLine + Count then
Mark.Line := Mark.Line - Count
else if Mark.Line > FirstLine + 1 then
Mark.Line := FirstLine;

procedure TCustomSynEdit.DoLinesInserted
there is:
if Mark.Line >= FirstLine then

should be:
if Mark.Line > FirstLine then

Another question is: should the mark shift down if the caret is somewhere inside the marked line (not the first and not the last position of the line) and I press Enter? I expect the mark stay.

[checkdigits]

I'm not 100% sure what you are asking for.

Can you split this into two issues - and give more detail on what you're wanting to see?

Please also use correct markdown for the code section like so:

if Mark.Line > FirstLine + Count then
  Mark.Line := Mark.Line - Count
else 
  if Mark.Line > FirstLine + 1 then
    Mark.Line := FirstLine;

[jacek-mulawka]

You are right, I should better use markdown, I am sorry.

Maybe I try to display screens to compare how works marks in e.g. Lazarus and SynEdit.
There can see the lines, the caret, the mark and how the mark shift to another lines (do not keep the line number 4).

variant A

variant B

variant C

variant D

If the mark should act this way, maybe it is OK, I only ask to confirm. If I wish marks behaviour similar to e.g. Lazarus I just overwrite local source and it is fine.

Thank you for the answer.