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/untangle.c b/untangle.c
index 4dfe208..10114b5 100644
--- a/untangle.c
+++ b/untangle.c
@@ -202,7 +202,7 @@ 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 < 4)
         return "Number of points must be at least four";
@@ -731,7 +731,7 @@ 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 a, b;
 
@@ -878,7 +878,7 @@ 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;
     int matrix[4];