#3899: mutt_ssl's interactive_check_cert() has several issues
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Reporter: kevin8t8 | Owner: mutt-dev
Type: defect | Status: closed
Priority: major | Milestone:
Component: crypto | Version:
Resolution: fixed | Keywords:
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Comment (by kevin8t8):
I figured out my confusion. !__must_be_array() in the Linux source was
comparing "a with &a[0]", not "&a with &a[0]".
So the meaning of the macro is BUILD_BUG_ON "if the parameter is true",
"otherwise return" ZERO.
Derek, I understand your general point, but I don't follow your logic in
comment:18. Saying you can just as easily make the array too small just
sounds argumentative to me. Your comment:19 shows that it's just as easy
to goof up the helper function. Both of these goof ups will show up with
a quick test, but I thought we were more discussing general code clarity
and maintainability here.
Again, I completely agree with your comment:10, but if we can avoid
misuse, there are situations where a mutt_array_size() makes the code
clearer, more concise, and less buggy. I wouldn't want to see it all over
the code, but for small self-contained functions I think it makes sense.
Yes, your helper function is perhaps clearer than the loop, but on the
other hand, the setting of menu->max is more brittle, and easier to forget
to change if a field is added to the helper.
Now, that said, I think hardcoding the menu->max beforehand is crap code,
but I'm trying to minimize my changes to this function, make it a little
better maintainable for the future, and move on. I think
mutt_array_size() accomplishes this marginally better than the helper
function.
Changing topics to the macro, the "BUILD_BUG" macro is pretty clever. It
takes the size of a struct with a bit field. A zero-length bit field will
end up returning a 0 size, but a negative bit field length is illegal and
will generate a compiler error.
The "must_be_array" uses Vincents comparison to make sure "a" is an array
and a not an array pointer.
The mutt_array_size() is modified to add the result of "must_be_array",
which will either return 0 or will generate a compilation error.
It's a little complicated, but not too bad (with a few comments thrown
in). I'm curious what Vincent's feedback is though, and if he has any
better ideas.
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Ticket URL: <https://dev.mutt.org/trac/ticket/3899#comment:24>
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