}
static int vbitmap_clear(int w, int h, struct solver_scratch *sc,
- int x, int y, int vbits, char *reason, ...)
+ int x, int y, int vbits, const char *reason, ...)
{
int done_something = FALSE;
int vbit;
int fs, bs, v;
int c1, c2;
#ifdef SOLVER_DIAGNOSTICS
- char *reason = "<internal error>";
+ const char *reason = "<internal error>";
#endif
if (soln[y*w+x])