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/pattern.c b/pattern.c
index e680553..45b1b0c 100644
--- a/pattern.c
+++ b/pattern.c
@@ -171,7 +171,7 @@ 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 <= 0 || params->h <= 0)
 	return "Width and height must both be greater than zero";
@@ -885,7 +885,7 @@ static char *new_game_desc(const game_params *params, random_state *rs,
     return desc;
 }
 
-static char *validate_desc(const game_params *params, const char *desc)
+static const char *validate_desc(const game_params *params, const char *desc)
 {
     int i, n, rowspace;
     const char *p;
@@ -1045,7 +1045,7 @@ static void free_game(game_state *state)
 }
 
 static char *solve_game(const game_state *state, const game_state *currstate,
-                        const char *ai, char **error)
+                        const char *ai, const char **error)
 {
     unsigned char *matrix;
     int w = state->common->w, h = state->common->h;
@@ -2021,7 +2021,8 @@ int main(int argc, char **argv)
 {
     game_params *p;
     game_state *s;
-    char *id = NULL, *desc, *err;
+    char *id = NULL, *desc;
+    const char *err;
 
     while (--argc > 0) {
         char *p = *++argv;