Add stpncpy()

include/string.h

@@ -53,6 +53,18 @@ char *__fortify_stpcpy(char *__restrict dest, const char *__restrict src)
 	return stpcpy(dest, src);
 }
 
+static inline __attribute__ ((always_inline))
+char *__fortify_stpncpy(char *__restrict dest, const char *__restrict src, size_t n)
+{
+	size_t bos = __builtin_object_size(dest, 0);
+
+	if (bos == (size_t)-1)
+		return stpcpy(dest, src);
+	if (__builtin_constant_p(n) && n > bos)
+		__builtin_trap();
+	return stpncpy(dest, src, n);
+}
+
 static inline __attribute__ ((always_inline))
 char *__fortify_strcat(char *__restrict dest, const char *__restrict src)
 {
@@ -142,6 +154,8 @@ size_t __fortify_strlcpy(char *__restrict dest, const char *__restrict src, size
 #define memset(dest, src, n) __fortify_memset(dest, src, n)
 #undef stpcpy
 #define stpcpy(dest, src) __fortify_stpcpy(dest, src);
+#undef stpncpy
+#define stpncpy(dest, src, n) __fortify_stpncpy(dest, src, n);
 #undef strcat
 #define strcat(dest, src) __fortify_strcat(dest, src)
 #undef strcpy