Re: full_read depends on incoming errno

[Andy Wingo]

On Thu 21 Feb 2013 17:29, Paolo Bonzini <address@hidden> writes:

> Il 20/02/2013 20:58, Andy Wingo ha scritto:
>> 
>>     if (full_read (fd, cookie, sizeof cookie) != sizeof cookie
>>         || full_read (fd, SCM_BYTEVECTOR_CONTENTS (bv),
>>                       SCM_BYTEVECTOR_LENGTH (bv)) != SCM_BYTEVECTOR_LENGTH 
>> (bv))
>>       {
>>         int errno_save = errno;
>>         (void) close (fd);
>>         errno = errno_save;
>>         if (errno)
>>           SCM_SYSERROR;
>>         scm_misc_error (FUNC_NAME, "file truncated while reading", SCM_EOL);
>>       }
>
> Doesn't it need to set errno to zero before calling full_read?

Not sure!  If full_read requires that errno be 0 going in, then yes, we
should.  Is this a requirement?

Otherwise, full_read sets errno to 0 if it returns a length less than
the length we asked for, and we're OK in that case AFAICS.

Andy
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