i.e. unprocessed bytes as positive number.
That is how the somewhat obscure return-value calculation works.
*/
- /* If offset is too large for return type, report error instead of wrong
- offset value. Buffers may not be larger than INT_MAX so the casts are
- safe.
+ /* If offset is too large for return type, report error instead of wrong
+ offset value.
*/
- /* FIXME: This calculation *underflows* when offset smaller than pre-read */
- if ( ( stream->pos.offset - ( (int)stream->bufend + (int)stream->ungetidx ) ) > ( LONG_MAX - stream->bufidx ) )
+ /* TODO: Check what happens when ungetc() is called on a stream at offset 0 */
+ if ( ( stream->pos.offset - stream->bufend ) > ( LONG_MAX - ( stream->bufidx - stream->ungetidx ) ) )
{
/* integer overflow */
_PDCLIB_errno = _PDCLIB_ERANGE;
return -1;
}
- return (long int)( stream->pos.offset - ( ( (int)stream->bufend - (int)stream->bufidx ) + stream->ungetidx ) );
+ long int res = ( stream->pos.offset - ( ( (int)stream->bufend - (int)stream->bufidx ) + stream->ungetidx ) );
+ return res;
}
#endif
FILE * fh;
TESTCASE( ( fh = tmpfile() ) != NULL );
TESTCASE( setvbuf( fh, buffer, _IOLBF, 4 ) == 0 );
+ /* Testing ungetc() at offset 0 */
+ rewind( fh );
+ TESTCASE( ungetc( 'x', fh ) == 'x' );
+ TESTCASE( ftell( fh ) == -1l );
+ rewind( fh );
+ TESTCASE( ftell( fh ) == 0l );
+ /* Commence "normal" tests */
TESTCASE( fputc( '1', fh ) == '1' );
TESTCASE( fputc( '2', fh ) == '2' );
TESTCASE( fputc( '3', fh ) == '3' );