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/dominosa.c b/dominosa.c
index 14d854f..a072ac6 100644
--- a/dominosa.c
+++ b/dominosa.c
@@ -749,7 +749,7 @@ static const char *validate_desc(const game_params *params, const char *desc)
     int n = params->n, w = n+2, h = n+1, wh = w*h;
     int *occurrences;
     int i, j;
-    char *ret;
+    const char *ret;
 
     ret = NULL;
     occurrences = snewn(n+1, int);