Layout fails on http://google.com due to unscanned text boxes

[jdm]

task 'LayoutTask' failed at 'Unscanned text boxes should have been scanned by now!', /home/jdm/sdb/servo-master/src/components/main/layout/box_.rs:1388
task 'LayoutTask' failed at 'Flow destroyed by going out of scope—this is unsafe! Use `destroy()` instead!', /home/jdm/sdb/servo-master/src/components/main/layout/flow.rs:803
task failed during unwinding (double-failure - total drag!)
rust must abort now. so sorry.

(gdb) bt
#0  0x0000000000f8d37a in rt::unwind::begin_unwind_inner::h95382ae01d8843a7Wfb::v0.10.pre ()
#1  0x000000000042e583 in rt::unwind::begin_unwind::h7ff81338756163d9fJv::v0.0 ()
#3  0x0000000000581d31 in layout..flow..BaseFlow::glue_drop.26332::hea75b71448bf183d () at /home/jdm/sdb/servo-master/src/components/main/layout/box_.rs:441
#4  0x00000000005dd386 in layout..block..BlockFlow::glue_drop.27219::h024d5f163499c7b6 () at /home/jdm/sdb/servo-master/src/components/main/layout/construct.rs:538
#5  0x00000000005dd33c in _$UP$layout..block..BlockFlow::glue_drop.27216::h67c599e520db56d1 () at /home/jdm/sdb/servo-master/src/components/main/layout/construct.rs:538
#6  0x0000000000582be1 in _$UP$layout..flow..Flow.Send::glue_drop.26374::h82ef20c2b49cd7e1 () at /home/jdm/sdb/servo-master/src/components/main/layout/flow.rs:803
#7  0x00000000005d7d08 in servo::layout::construct::FlowConstructor<'a>::build_flow_using_children (self=0x7ffff42c2130, flow=..., node=0x7ffff42b23d8)
    at /home/jdm/sdb/servo-master/src/components/main/layout/construct.rs:484
#8  0x00000000005dd292 in servo::layout::construct::FlowConstructor<'a>::build_flow_for_block (self=0x7ffff42c2130, node=0x7ffff42b23d8) at /home/jdm/sdb/servo-master/src/components/main/layout/construct.rs:539
#9  0x00000000005d894d in process (self=<optimized out>, node=<optimized out>, self=<optimized out>, node=<optimized out>) at /home/jdm/sdb/servo-master/src/components/main/layout/construct.rs:1001
#10 servo::layout::construct::FlowConstructor<'a>::build_flow_using_children (self=0x7ffff42c2130, flow=..., node=0x7ffff42ba2f8) at /home/jdm/sdb/servo-master/src/components/main/layout/construct.rs:491
#11 0x00000000005dd292 in servo::layout::construct::FlowConstructor<'a>::build_flow_for_block (self=0x7ffff42c2130, node=0x7ffff42ba2f8) at /home/jdm/sdb/servo-master/src/components/main/layout/construct.rs:539
#12 0x00000000005d894d in process (self=<optimized out>, node=<optimized out>, self=<optimized out>, node=<optimized out>) at /home/jdm/sdb/servo-master/src/components/main/layout/construct.rs:1001
#13 servo::layout::construct::FlowConstructor<'a>::build_flow_using_children (self=0x7ffff42c2130, flow=..., node=0x7ffff42c2148) at /home/jdm/sdb/servo-master/src/components/main/layout/construct.rs:491
#14 0x00000000005dd292 in servo::layout::construct::FlowConstructor<'a>::build_flow_for_block (self=0x7ffff42c2130, node=0x7ffff42c2148) at /home/jdm/sdb/servo-master/src/components/main/layout/construct.rs:539
#15 0x00000000004f6845 in process (self=0x7ffff42c2130, node=0x7ffff42c2148) at /home/jdm/sdb/servo-master/src/components/main/layout/construct.rs:1001
#16 servo::css::matching::LayoutNode<'ln>.MatchMethods::recalc_style_for_subtree (self=0x7ffff42ca020, stylist=0x7fffdc003f90, layout_context=0x7ffff4318d98, font_context=0x0, applicable_declarations=
    0x7ffff43187c8, applicable_declarations_cache=0x7ffff43187b0, style_sharing_candidate_cache=0x7ffff4318790, parent=...) at /home/jdm/sdb/servo-master/src/components/main/css/matching.rs:525
#17 0x00000000004f5cfe in servo::css::matching::LayoutNode<'ln>.MatchMethods::recalc_style_for_subtree (self=0x7ffff42d1e90, stylist=0x7fffdc003f90, layout_context=0x7ffff4318d98, font_context=0x0, 
    applicable_declarations=0x7ffff43187c8, applicable_declarations_cache=0x7ffff43187b0, style_sharing_candidate_cache=0x7ffff4318790, parent=...)
    at /home/jdm/sdb/servo-master/src/components/main/css/matching.rs:513
#18 0x00000000004f5cfe in servo::css::matching::LayoutNode<'ln>.MatchMethods::recalc_style_for_subtree (self=0x7ffff42d9d00, stylist=0x7fffdc003f90, layout_context=0x7ffff4318d98, font_context=0x0, 
    applicable_declarations=0x7ffff43187c8, applicable_declarations_cache=0x7ffff43187b0, style_sharing_candidate_cache=0x7ffff4318790, parent=...)
    at /home/jdm/sdb/servo-master/src/components/main/css/matching.rs:513
#19 0x00000000004f5cfe in servo::css::matching::LayoutNode<'ln>.MatchMethods::recalc_style_for_subtree (self=0x7ffff42e1b70, stylist=0x7fffdc003f90, layout_context=0x7ffff4318d98, font_context=0x0, 
    applicable_declarations=0x7ffff43187c8, applicable_declarations_cache=0x7ffff43187b0, style_sharing_candidate_cache=0x7ffff4318790, parent=...)
    at /home/jdm/sdb/servo-master/src/components/main/css/matching.rs:513
#20 0x00000000004f5cfe in servo::css::matching::LayoutNode<'ln>.MatchMethods::recalc_style_for_subtree (self=0x7ffff42e99e0, stylist=0x7fffdc003f90, layout_context=0x7ffff4318d98, font_context=0x0, 
    applicable_declarations=0x7ffff43187c8, applicable_declarations_cache=0x7ffff43187b0, style_sharing_candidate_cache=0x7ffff4318790, parent=...)
    at /home/jdm/sdb/servo-master/src/components/main/css/matching.rs:513
#21 0x00000000004f5cfe in servo::css::matching::LayoutNode<'ln>.MatchMethods::recalc_style_for_subtree (self=0x7ffff42f1850, stylist=0x7fffdc003f90, layout_context=0x7ffff4318d98, font_context=0x0, 
    applicable_declarations=0x7ffff43187c8, applicable_declarations_cache=0x7ffff43187b0, style_sharing_candidate_cache=0x7ffff4318790, parent=...)
    at /home/jdm/sdb/servo-master/src/components/main/css/matching.rs:513
#22 0x00000000004f5cfe in servo::css::matching::LayoutNode<'ln>.MatchMethods::recalc_style_for_subtree (self=0x7ffff42f96c0, stylist=0x7fffdc003f90, layout_context=0x7ffff4318d98, font_context=0x0, 
    applicable_declarations=0x7ffff43187c8, applicable_declarations_cache=0x7ffff43187b0, style_sharing_candidate_cache=0x7ffff4318790, parent=...)
    at /home/jdm/sdb/servo-master/src/components/main/css/matching.rs:513
#23 0x00000000004f5cfe in servo::css::matching::LayoutNode<'ln>.MatchMethods::recalc_style_for_subtree (self=0x7ffff4301530, stylist=0x7fffdc003f90, layout_context=0x7ffff4318d98, font_context=0x0, 
    applicable_declarations=0x7ffff43187c8, applicable_declarations_cache=0x7ffff43187b0, style_sharing_candidate_cache=0x7ffff4318790, parent=...)
    at /home/jdm/sdb/servo-master/src/components/main/css/matching.rs:513
#24 0x00000000004f5cfe in servo::css::matching::LayoutNode<'ln>.MatchMethods::recalc_style_for_subtree (self=0x7ffff43093a0, stylist=0x7fffdc003f90, layout_context=0x7ffff4318d98, font_context=0x0, 
    applicable_declarations=0x7ffff43187c8, applicable_declarations_cache=0x7ffff43187b0, style_sharing_candidate_cache=0x7ffff4318790, parent=...)
    at /home/jdm/sdb/servo-master/src/components/main/css/matching.rs:513
#25 0x00000000004f5cfe in servo::css::matching::LayoutNode<'ln>.MatchMethods::recalc_style_for_subtree (self=0x7ffff4311210, stylist=0x7fffdc003f90, layout_context=0x7ffff4318d98, font_context=0x0, 
    applicable_declarations=0x7ffff43187c8, applicable_declarations_cache=0x7ffff43187b0, style_sharing_candidate_cache=0x7ffff4318790, parent=...)
    at /home/jdm/sdb/servo-master/src/components/main/css/matching.rs:513
#26 0x00000000004f5cfe in servo::css::matching::LayoutNode<'ln>.MatchMethods::recalc_style_for_subtree (self=0x7ffff43192c8, stylist=0x7fffdc003f90, layout_context=0x7ffff4318d98, font_context=0x0, 
    applicable_declarations=0x7ffff43187c8, applicable_declarations_cache=0x7ffff43187b0, style_sharing_candidate_cache=0x7ffff4318790, parent=...)
    at /home/jdm/sdb/servo-master/src/components/main/css/matching.rs:513
#27 0x000000000064d5ca in fn28650 () at /home/jdm/sdb/servo-master/src/components/main/layout/layout_task.rs:583
#28 0x000000000064d2b9 in time::profile::he1fbcded758d2256xHA::v0.0 () at /home/jdm/sdb/servo-master/src/components/main/layout/layout_task.rs:574
#29 0x0000000000644363 in servo::layout::layout_task::LayoutTask::handle_reflow (self=0x7ffff4319c58, data=0x7fffec0279d0) at /home/jdm/sdb/servo-master/src/components/main/layout/layout_task.rs:574
#30 0x00000000006438f0 in fn28460 () at /home/jdm/sdb/servo-master/src/components/main/layout/layout_task.rs:355
#31 0x00000000004be9ae in time::profile::h08ea46eeae50615bxHA::v0.0 () at /home/jdm/sdb/servo-master/src/components/main/compositing/compositor.rs:739
#32 0x000000000063e3dc in servo::layout::layout_task::LayoutTask::handle_request (self=0x7ffff4319c58) at /home/jdm/sdb/servo-master/src/components/main/layout/layout_task.rs:354
#33 0x000000000061ebe2 in servo::layout::layout_task::LayoutTask::start (self=0x7ffff4319c58) at /home/jdm/sdb/servo-master/src/components/main/layout/layout_task.rs:322
#34 0x000000000061e0b1 in fn27937 () at /home/jdm/sdb/servo-master/src/components/main/layout/layout_task.rs:275
#35 0x0000000000d30c88 in task::bootstrap_green_task::closure.7058 ()
#36 0x0000000001022273 in rt::task::Task::run::closure.40680 ()
#37 0x000000000102d17c in rust_try ()
#38 0x00000000010220d2 in rt::task::Task::run::h7977c6fd6d6e0e93148::v0.10.pre ()
#39 0x0000000000d30b3a in task::bootstrap_green_task::ha6a1ce90f7e00c6dZ5b::v0.10.pre ()
#40 0x0000000000000000 in ?? ()

[larsbergstrom]

Dupe of #2065