Returned sources are broken if the sourceRoot contains hyphens

[rakeshpai]

Found a weird bug where stuff after a hyphen in the sourceRoot gets snipped off when determining the sources in a consumer. I think the code below will show it best.

var smc = new SourceMapConsumer(map);
console.log(smc.sourceRoot); // null
console.log(smc.sources); // Prints a list of sources. Say ["/script.js"]. Everything's fine so far.

smc.sourceRoot = "http://x-y.com";
console.log(smc.sources); // Prints ["http://x/script.js"]. The "-y.com" disappears

Let me know if I can help with more details.