+/* The maximum value that getndelim2 can return without suffering from
+ overflow problems, either internally (because of pointer
+ subtraction overflow) or due to the API (because of ssize_t). */
+#define GETNDELIM2_MAXIMUM (PTRDIFF_MAX < SSIZE_MAX ? PTRDIFF_MAX : SSIZE_MAX)
+
+/* Try to add at least this many bytes when extending the buffer.
+ MIN_CHUNK must be no greater than GETNDELIM2_MAXIMUM. */