get-bytevector-n! reads too many bytes

[Gwen Weinholt]

This test program demonstrates the bug:

(import (rnrs))

(define (print . x) (for-each display x) (newline))

(let ((test-file "reading-bug-test.bin"))
  (when (file-exists? test-file)
    (delete-file test-file))
  (let ((p (open-file-output-port test-file)))
    (put-bytevector p '#vu8(1 2 3 4 5 6 7 8 9))
    (close-port p))
  (let ((p (open-file-input-port test-file))
        (buf (make-bytevector 10 #xff)))
    (print "going to read 5 bytes: " (get-bytevector-n! p buf 0 5))
    (print "result: " buf)
    (print "going to read 1 byte: " (get-bytevector-n! p buf 5 1))
    (print "result: " buf)
    (unless (bytevector=? buf '#vu8(1 2 3 4 5 6 #xff #xff #xff #xff))
      (print "the data is not correct"))
    (close-port p)))

The problem is that the second get-bytevector-n! call reads too many bytes. Here is the output from the 64-bit build, rev 1816, on Debian Lenny amd64:

going to read 5 bytes: 5
result: #vu8(1 2 3 4 5 255 255 255 255 255)
going to read 1 byte: 4
result: #vu8(1 2 3 4 5 6 7 8 9 255)
the data is not correct

[Abdulaziz Ghuloum (aghuloum)]

Fixed in 1818. Thanks.