Tabs are apparently used this way on the front page of plwiki.
Change-Id: I0a65d5a9783071e91696ed2b96887f44199a999d
+!! test
+Tabs don't trigger preformatted text
+!! input
+ This is not
+ preformatted text.
+ This is preformatted text.
+ So is this.
+!! result
+<p> This is not
+ preformatted text.
+</p>
+<pre>This is preformatted text.
+ So is this.
+</pre>
+!! end
+
!! test
Ident preformatting with inline content
!! input
!! test
Ident preformatting with inline content
!! input