treedrawing: fix bug where rare circumstances could lead to incorrect indent

The problem took me a while to find, but the issue here was that push_buf does
not add a terminating null byte, and I was only asking push_buf to copy the
bytes that contained characters, not the terminating null byte as well.

This, combined with the fact that to remove bytes from the end of the buffer, I
just placed a null byte a the end, caused some combinations of indentation and
dedentations to overwrite the null byte, and not place a null byte after the new
indent, which would still contain data from a previous indentation.

src/treedrawing.c

@@ -6,7 +6,7 @@
 /*   By: khais <marvin@42.fr>                       +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2025/03/18 15:24:50 by khais             #+#    #+#             */
-/*   Updated: 2025/03/19 12:09:47 by khais            ###   ########.fr       */
+/*   Updated: 2025/03/19 14:00:35 by khais            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -40,7 +40,7 @@ void	dedent(t_buffer *leader, bool is_last)
 	idx = leader->length - length_to_remove;
 	if (idx >= 0)
 	{
-		leader->buffer[idx] = '\0';
+		ft_bzero(leader->buffer + idx, length_to_remove);
 		leader->length = idx;
 	}
 }

src/treedrawing.h

@@ -6,7 +6,7 @@
 /*   By: khais <marvin@42.fr>                       +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2025/03/18 12:24:25 by khais             #+#    #+#             */
-/*   Updated: 2025/03/19 12:10:05 by khais            ###   ########.fr       */
+/*   Updated: 2025/03/19 13:50:37 by khais            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -21,6 +21,11 @@
 # define VERTICAL " │  "
 # define SPACE    "    "
 
+/* # define CROSS    " |- " */
+/* # define CORNER   " \\- " */
+/* # define VERTICAL " |  " */
+/* # define SPACE    "    " */
+
 void	indent(t_buffer *indent, bool is_last);
 void	dedent(t_buffer *indent, bool is_last);