Return error messages as 'const char *', not 'char *'.

They're never dynamically allocated, and are almost always string
literals, so const is more appropriate.

1 files changed, 3 insertions, 3 deletions

diff --git a/dominosa.c b/dominosa.c
index d26f97a..14d854f 100644
--- a/dominosa.c
+++ b/dominosa.c
@@ -191,7 +191,7 @@ static game_params *custom_params(const config_item *cfg)
     return ret;
 }
 
-static char *validate_params(const game_params *params, int full)
+static const char *validate_params(const game_params *params, int full)
 {
     if (params->n < 1)
         return "Maximum face number must be at least one";
@@ -744,7 +744,7 @@ static char *new_game_desc(const game_params *params, random_state *rs,
     return ret;
 }
 
-static char *validate_desc(const game_params *params, const char *desc)
+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;
@@ -871,7 +871,7 @@ static void free_game(game_state *state)
 }
 
 static char *solve_game(const game_state *state, const game_state *currstate,
-                        const char *aux, char **error)
+                        const char *aux, const char **error)
 {
     int n = state->params.n, w = n+2, h = n+1, wh = w*h;
     int *placements;