prefer (X ? 1 : -1) when converting from boolean (1,0) to int (1,-1)

[pspp] / lib / xstrtoll.c

#define __strtol strtoll
#define __strtol_t long long int
#define __xstrtol xstrtoll
#define STRTOL_T_MINIMUM LLONG_MIN
#define STRTOL_T_MAXIMUM LLONG_MAX
#include "xstrtol.c"