[bug #38640] GSScanDouble should use strtod

[Larry Campbell]

Follow-up Comment #1, bug #38640 (project gnustep):

More info:


We occasionally see things like this in the fpconfigloader log and in
configuration change confirmation emails:

2012-06-26 16:12:51.402 fpconfigloader[15552]   Property "www" changed:
2012-06-26 16:12:51.402 fpconfigloader[15552]     loadImbalanceFactor changed:
"1.9" => "1.9"

which is harmless but annoying. This turns out to be because the load
imbalance factor comes from the portal as an integer string, "90", which is
converted as follows:

        [self setLoadImbalanceFactor:[NSNumber
numberWithDouble:(((double)[[soap_property
objectForKey:@"loadImbalanceFactor"] unsignedIntValue])/100.0) + 1.0]];

more concisely summarized as, essentially:

        x = 90 / 100.0 + 1.0;

which is 1.9, but that can't be represented exactly, and actually results in
1.8999999999999999.

The problem is that -[NSString doubleValue], which is used by FPFile.m when
parsing stored dynamic config files, ends up calling GSScanDouble in
NSScanner.m, which does not use atof or strtod, instead using its own
home-grown parser that returns:

        1.9000000000000001


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