+2011-09-21 Dan Bernstein <mitz@apple.com>
+
+ <rdar://problem/9768483> REGRESSION: Crash in RenderBlock::removeFloatingObjectsBelow()
+ https://bugs.webkit.org/show_bug.cgi?id=68550
+
+ Reviewed by Darin Adler.
+
+ Test: fast/multicol/null-lastFloat-in-removeFloatingObjectsBelow.html
+
+ * rendering/RenderBlock.cpp:
+ (WebCore::RenderBlock::removeFloatingObjectsBelow): Break out of the while() loop when the
+ floating object set is empty, which can happen if there were no floats on previous lines
+ (in which case, lastFloat is 0).
+