fix grid formatting for labelled boxed scalars

Author: kaikalii

src/grid_fmt.rs

@@ -554,7 +554,7 @@ impl GridFmt for Boxed {
                     for row in &mut grid {
                         row.insert(0, ' ');
                     }
-                    grid[(height - 1) / 2][0] = symbol;
+                    grid[height / 2][0] = symbol;
                 }
             }
         }

tests/grid.ua

@@ -75,3 +75,18 @@ $          ┘
 ⍤⤙≍ ¤"[\"1\"│]" pretty {"1"}
 ⍤⤙≍ ¤"[¤\"1\"│]" pretty {¤"1"}
 ⍤⤙≍ ¤"[¤\"23\"│]" pretty {¤"23"}
+
+# Labels
+pretty {$a 5 $b 6}
+$ ┌─       
+$    a│ b  
+$   ∙5│∙6  
+$         ┘
+⍤⤙≍ ⊜∘⊸≠@\n
+
+pretty {$a 5 $b @x}
+$ ┌─       
+$    a│b   
+$   ∙5│@x  
+$         ┘
+⍤⤙≍ ⊜∘⊸≠@\n