Hex-Rays and negative structure offsets

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Find your struct in Local Types and Edit it. See if it matches what you think it should be. Find you struct in Structures, open it up with ctrl-+ and you'll see all your struct members and their offsets (sorry, I'm sure you know all this). My point is - alignment. It can easily be diffent to what you think. If you are inputing your structs to IDA as a *.h file, rather than directly into Local Types, then there is an even bigger chance of the alignment beig different. I'm never sure if alignment directives in *.h files fed to IDA get interpretted or not, IDA often seems to align struct member of a 4 byte boundary for a 32 bit PE and 8 bytes for a 64bit PE.

Actually, I'm wondering... you *did* give IDA your struct definitions, yes?

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