[patch libcpp]: Issue about st_size comparison

[Dave Korn]

Kai Tietz wrote:

  Hi Kai... I don't understand this patch, so I have a few questions:

> on windows target x64 ssize_t has size of 64-bits, but the st_size
> field in struct stat remains for 32-bit API version 32-bit type long.
> So the comparison 'file->st.st_size > INTTYPE_MAXIMUM (ssize_t)' is
> always zero, 

  Why is that wrong, rather then the correct thing to happen?  It means that
you can never have a file too large, because a 64-bit address space will
always swallow a 32-bit range of file offsets with room to spare.

> which leads for stage 2 build to fail.

  In what way does it fail?

> -      if (file->st.st_size > INTTYPE_MAXIMUM (ssize_t))
> +      if ((ssize_t) file->st.st_size > INTTYPE_MAXIMUM (ssize_t))

  In what way is the comparison not still always zero after this change?  I
don't see how the compiler won't assume an ssize_t value (the casted value on
the LHS) could never exceed the INTTYPE_MAXIMUM for the type.

  Oh, btw, trivial typo in the ChangeLog: "file.c" vs. "files.c"

    cheers,
      DaveK