Test the ".1" and "1." cases which are assumed to be problematic on
MacOS (or may not have been supported before a recent update). Add more
tests with leading signs as well as whitespace instead of a sign.
The previous implementation only echoed the p/q conversion results _if_
the return code signalled success but the result was unexpected. Although
the errno value for failed conversion attempts (non-zero return codes)
is not too helpful, seeing which text input failed the test is desirable.
Values like '-0.1' would be parsed as being positive, as the integral
type does not discern +0 and -0. Also allow values without leading
integral value, to match behaviour of strtod/sr_atof.
The method accepts strings with numbers in scientific or normal notation,
e.g. -1.25 or 3.37e-6. The numeric range is limited by the sr_rational
range, i.e +-9.2e18, resolution is ~19 digits.
Since Autoconf places some important feature flags only into the
configuration header, it is necessary to include it globally to
guarantee a consistent build.
Gerhard Sittig
Frank Stettner
Uwe Hermann
Stefan Brüns
Soeren Apel
Daniel Elstner