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, 5 insertions, 4 deletions

diff --git a/singles.c b/singles.c
index 32d5965..c88c6c5 100644
--- a/singles.c
+++ b/singles.c
@@ -251,7 +251,7 @@ 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->w < 2 || params->h < 2)
 	return "Width and neight must be at least two";
@@ -1181,7 +1181,7 @@ static int solve_specific(game_state *state, int diff, int sneaky)
 }
 
 static char *solve_game(const game_state *state, const game_state *currstate,
-                        const char *aux, char **error)
+                        const char *aux, const char **error)
 {
     game_state *solved = dup_game(currstate);
     char *move = NULL;
@@ -1410,7 +1410,7 @@ randomise:
     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)
 {
     char *ret = NULL;
 
@@ -1906,7 +1906,8 @@ static void start_soak(game_params *p, random_state *rs)
 
 int main(int argc, char **argv)
 {
-    char *id = NULL, *desc, *desc_gen = NULL, *tgame, *err, *aux;
+    char *id = NULL, *desc, *desc_gen = NULL, *tgame, *aux;
+    const char *err;
     game_state *s = NULL;
     game_params *p = NULL;
     int soln, soak = 0, ret = 1;