Make the code base clean under -Wwrite-strings.

I've also added that warning option and -Werror to the build script,
so that I'll find out if I break this property in future.

1 files changed, 1 insertions, 1 deletions

diff --git a/mines.c b/mines.c
index 6304668..6a854c6 100644
--- a/mines.c
+++ b/mines.c
@@ -2558,7 +2558,7 @@ uncover:
 		 * can.
 		 */
 		char *p = buf;
-		char *sep = "";
+		const char *sep = "";
 
 		for (dy = -1; dy <= +1; dy++)
 		    for (dx = -1; dx <= +1; dx++)