/^.+<\?/i.test('<?') gives true in Edge 40.15063.0.0 but false in other browsers/engines

[martin-honnen]

I think in https://stackoverflow.com/questions/45122823/is-there-any-reason-why-edge-returns-true-for-xml-i-testxml-version I have found a bug with the regular expression test method in the Javascript engine of Edge 40.15063.0.0.

var xml = '<?';
var regex = /^.+<\?/i;
var test = regex.test(xml);

As there is no character at all before the < less-than sign in the input string the match ^.+ should not match anything and therefore that test call should return false and not true as it does in the cited Edge version.

[MizardX]

/^.+%x/.test('%x') displays the same bug. Tested in Edge 41.16232.1000.0

[martin-honnen]

Based on the tests added in a8e157a#diff-18608f601e3f7519b31ec8d2d2e28e25 it looks as if that fix already tries to address the posted problem with /^.+.

[MikeHolman]

You're right. I verified in our console host and your bug is fixed by #3201, which will ship as part of the next version of Edge.

[curtisman]

Closing the issue as this is already fixed in ChakraCore v1.6 and master