Fix right click in selection of additional caret

[jmb462]

Fix #76417

Issue description

Right click in the selection of any secondary caret discard all selections and show context menu has is there was no selection.

Investigations

In ScriptTextEditor::_text_edit_gui_input(const Ref<InputEvent> &ev) multicaret is not managed when checking if click was in a selection. It only check the main caret selection. If it's outside the main caret selection, it discards all secondary caret and all selections.

Fix proposal

(modified version after taking comments into account)

Managed multicarret in ScriptTextEditor::_text_edit_gui_input(const Ref<InputEvent> &ev) : iterate throw each caret selection to check if right click is in any of the caret selections. Keep all selection.

Same modification in void TextEdit::gui_input(const Ref<InputEvent> &p_gui_input) : only one caret selection was checked. Iterates throw all selections and keep it all.

Before

After

[ajreckof]

Is there a particular reason we should only keep one of the selection and not all of them?

[jmb462]

Is there a particular reason we should only keep one of the selection and not all of them?

In VS Code, we can copy multiselection and selections are each pasted on a different line.
So maybe we could also keep all selections and do the same.

(edit : Done)

[ajreckof]

Is there a particular reason we should only keep one of the selection and not all of them?

In VS Code, we can copy multiselection and selections are each pasted on a different line. So maybe we could also keep all selections and do the same.

Your coment made me realise that it is already the case for keyboard shortcut and therefore it would be even stranger not to do it for right click.

[jmb462]

Thanks to @ajreckof comments, it clearly appears that we have to keep all carets when right clicking on a selection.

I've modified this PR in this way.

[Paulb23]

Nice find and fix!

Couple small notes inline

[akien-mga]

Thanks!

[akien-mga]

Cherry-picked for 4.0.3.