Re: [lwip-users] Bug in inet_chksum_pseudo() produces bad checksum(Paradigm C++)

[Jonathan Larmour]

David Empson wrote:
> Dave - you should look for any other places in the LWIP code where a 
> similar test is being done. I suspect the bug will only happen in the 
> case where an explicit shift-right-16 is done on a 32-bit expression, 
> and there is an implied test for zero, i.e. something like "if (expr >> 
> 16)" or "while (expr >> 16)".

Kieran had already fixed the reported ones in inet.c and I just did a few 
more. It does make you think that if you can't trust the compiler, you 
just won't know what code works or doesn't work in anything you build.

A run of this command:
egrep -r '(if|while).*>> 16' .

only shows instances in inet.c and inet6.c, the latter of which seems 
unlikely to need addressing (I imagine Paradigm C++ will be fixed before 
IPv6 support moves out of the experimental stage).

Jifl
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