Description:
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When using the convert.quoted-printable-encode stream filter, if the stream contains a single bare CR line ending at the end of the stream when line-break-chars is set to CRLF this can cause a segfault with certain values of line-length.

Changing the line-length in the test script, or setting line-break-chars to "\r" prevents the segfault.

Test script:
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$data = fopen('php://temp', 'r+');
fwrite($data, "test\r\ntest\r\n\r");

$stream = fopen("php://temp", 'r+');
stream_filter_append($stream, 'convert.quoted-printable-encode', STREAM_FILTER_WRITE, array('line-length' => 5, 'line-break-chars' => "\r\n"));
rewind($data);
stream_copy_to_stream($data, $stream);

Expected result:
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The data should be copied from the $data stream to the $stream stream, applying the convert filter.

Actual result:
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Segfault.