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96d2a21683
Right-shifting negative values has implementation-defined behavior.
On all the platforms we work on right now, the behavior is to
sign-extend the input. That isn't what we wanted in
auth_type_val = (descriptor_cookie_tmp[16] >> 4) + 1;
Fix for 6861; bugfix on 0.2.1.5-alpha; reported pseudonymously.
The broken behavior didn't actually hurt anything, I think, since the
only way to get sign-extension to happen would be to have the top bit
of descriptor_cookie_tmp[16] set, which would make the value of
descriptor_cookie_tmp[16] >> 4 somewhere between 0b11111111 and
0b11111000 (that is, between -1 and -8). So auth_type_val would be
between -7 and 0. And the immediate next line does:
if (auth_type_val < 1 || auth_type_val > 2) {
So the incorrectly computed auth_type_val would be rejected as
invalid, just as a correctly computed auth_type_val would be.
Still, this stuff shouldn't sit around the codebase.
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