Bug#774712: io-jasper invalid operation

[Mathieu Malaterre]

Package: gdk-pixbuf
Version: 2.31.1-2
Tags: upstream patch

The following code in io-jasper.c looks suspicious:

[...]
  if (jas_stream_write (context->stream, buf, size) < 0) {
    g_set_error_literal (error, GDK_PIXBUF_ERROR,
GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY,
[...]

here size is usually a small size (4096...). However in jasper we have:

[...]
/* Write characters from a buffer to a stream. */
int jas_stream_write(jas_stream_t *stream, const void *buf, int cnt);
[...]

Where implementation is:

int jas_stream_write(jas_stream_t *stream, const void *buf, int cnt)
{
  int n;
  const char *bufptr;

  bufptr = buf;

  n = 0;
  while (n < cnt) {
    if (jas_stream_putc(stream, *bufptr) == EOF) {
      return n;
    }
    ++bufptr;
    ++n;
  }

  return n;
}

therefore the return value can never be below zero. I suggest changing
the code to:

  if (jas_stream_write (context->stream, buf, size) != size ) {