Additional attribute '\t'='' appears if we use multiline attributes

[Inversion-des]

There is some problem with render:

div
	p[
		id="marvin"
		class="martian"
		data-info="Illudium Q-36"
	]
	p Next line

produces <div><p \t="" class="martian" data-info="Illudium Q-36" id="marvin"></p><p>Next line</p></div> Attribute \t="" is wrong here.

[Inversion-des]

I use this workaround (https://github.com/Inversion-des/slim/commit/8857e41eeda9d97f5d158ad19b0683e119c4e8c9), but there should be some better solution.