`TagHelperOutputExtensions.RemoveRange()` does not handle its `attributes` parameter safely

[dougbu]

the following code:

var attributes = tagHelperOutput.Attributes
    .Where(item => item.Name.StartsWith("route-", StringComparison.OrdinalIgnoreCase));
tagHelperOutput.RemoveRange(attributes);

throws an InvalidOperationException with Message == "Collection was modified; enumeration operation may not execute."

RemoveRange() should use ToArray() or ToList() to avoid such issues in its for loop.

[Eilon]

@ajaybhargavb please write a failing unit test first, TDD style. Then fix.

[Eilon]

Need to mark as "Done"?