Use an arrow to indicate the current line

[CatsDeservePets]

Due to lack of validation and the way relative line numbers are padded, one can misuse the new numbercursorfmt option to use symbols like arrows as the current line indicator (it's not a bug, it's a feature😃):

set relativenumber # It won't work otherwise
set numbercursorfmt "➤"

[joelim-work]

I guess you can prevent the misuse by parsing numberfmt/numbercursorfmt into a Tcell style and then use that directly when printing:

diff --git a/ui.go b/ui.go
index 3aac8e8..784cfe0 100644
--- a/ui.go
+++ b/ui.go
@@ -455,11 +455,11 @@ func (win *win) printDir(ui *ui, dir *dir, context *dirContext, dirStyle *dirSty
 				}
 			}
 
-			fmtStr := optionToFmtstr(gOpts.numberfmt)
+			fmtStr := gOpts.numberfmt
 			if i == dir.pos && gOpts.numbercursorfmt != "" {
-				fmtStr = optionToFmtstr(gOpts.numbercursorfmt)
+				fmtStr = gOpts.numbercursorfmt
 			}
-			win.print(ui.screen, 0, i, tcell.StyleDefault, fmt.Sprintf(fmtStr, ln))
+			win.print(ui.screen, 0, i, parseEscapeSequence(fmtStr), ln)
 		}
 
 		path := filepath.Join(dir.path, f.Name())

[CatsDeservePets]

I mean you could do that. However, you can kinda break/glitch the UI in many ways (almost everywhere, format strings are allowed). It is up to the user what they put in there in my opinion.