This actually looks very wrong. First, it would try to read bits for
len == 0, which means it was actually reading the implicit NUL from
QByteArray (so valgrind would never catch the error).
Second, there was a corner case for testing the 8th bit (bit 7) in the
last byte. For len == 8 or 16 at the beginning of the last loop, it
would read bits[len / 8], which is again the implicit NUL from
QByteArray.
Compare to testBit (simplified):
return d.constData()[1+(i>>3)] & (1 << (i & 7)) != 0;
Task-number: QTBUG-11625
Change-Id: Idb361163de596b629cab42f2367ddd09456c2a98
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Kurt Pattyn <pattyn.kurt@gmail.com>
873ae53d47