Edge case for XML conversion

[arcanechimp]

When converting from XML to a map I have found that a string value of "NAN", gets cast to a float value as a NaN. This is not the desired result in this particular case, as it is actually a string value.

There is no NaN equivalent in JSON, so when converting from a Map to JSON, I get an error:
json: unsupported value: NaN

I assume this issue would also arise if there was a string value of "Inf" or "-Inf".

I have written a small example below to replicate the issue.

package main

import (
    "fmt"

    "github.com/clbanning/mxj"
)

func main() {
    var xml = []byte("<foo><bar>NAN</bar></foo>")

    m, err := mxj.NewMapXml(xml, true)
    if err != nil {
        panic(err)
    }

    fmt.Print(m.StringIndent())
    fmt.Println()

    j, err := m.JsonIndent("", "  ", true)
    if err != nil {
        panic(err)
    }

    fmt.Print(string(j))
}

[clbanning]

patched. thanks.