A linha vertical branca oferece a capacidade de recolher todo o código dentro dessa função, o if, o each, etc. Isso é chamado de folding . Alguns acham útil quando tentam pesquisar / localizar código porque ocultam coisas que podem achar desnecessárias.
If you don't like it or don't need it at all, you can simply disable folding support completely in the preferences dialog.
The folding behavior can be changed with the "Fold/Unfold all children of a fold point" option in the preference dialog. If activated, Geany will unfold all nested fold points below the current one if they are already folded (when clicking on a [+] symbol). When clicking on a [-] symbol, Geany will fold all nested fold points below the current one if they are unfolded.
This option can be inverted by pressing the Shift key while clicking on a fold symbol. That means, if the "Fold/Unfold all children of a fold point" option is enabled, pressing Shift will disable it for this click and vice versa.