Spelling fix: usefull --> useful.jesstess-docs

Thank you Curtis Brown for the patch.

This resolves bug #27052.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/mark.c b/src/mark.c
index ccb74f9..35c2178 100644
--- a/src/mark.c
+++ b/src/mark.c
@@ -771,7 +771,7 @@ processchar:
             LGotoPos(flayer, cx, W2D(cy));
 	  break;
 	case '@':
-	  /* it may be usefull to have a key that does nothing */
+	  /* it may be useful to have a key that does nothing */
 	  break;
 	case '%':
 	  rep_cnt--;