Assigning this to me. Lets make this bug a place for LayoutNG DevTools issues.

Also: kjlubick
With the LayoutNG experiment enabled, I couldn't scroll any files in the sources tab of DevTools.  This meant I could only debug things in the top 100 lines of code or so :)

To clarify #c1, I'm on Linux running Chrome Version 70.0.3538.77 (64-bit)


Nothing "unusual" about my setup, AFAIK.

@mstensho: Dup of  crbug.com/885185  ?

We should fix this. Attaching the minimum reproducible case.

The problem is that 
{ display: inline-block; width: auto, min-width: 100% }
is getting resolved to kFitContent width, instead of width of ConstraintSpace().

I tried fixing it, but there are too many unknowns in play.
My suspicion is that ng_line_breaker is incorrectly resolving inline-block's min-width:100% to kFitContent around ng_line_breaker:811

Deleted: test.html 450 bytes

test.html 450 bytes View Download

Thanks for reducing that! Further simplified TC with no flexbox attached.

ComputeInlineSizeForFragment() seems to be a bit closer to the problem:

#0  blink::ComputeInlineSizeForFragment (space=..., node=..., border_padding=..., override_minmax=0x0) at ../../third_party/blink/renderer/core/layout/ng/ng_length_utils.cc:523
#1  0x00007fffe2b14111 in blink::CalculateBorderBoxSize (constraint_space=..., node=..., block_content_size=-1px, border_padding=...) at ../../third_party/blink/renderer/core/layout/ng/ng_length_utils.cc:1039
#2  0x00007fffe2ae40ba in blink::NGBlockLayoutAlgorithm::Layout (this=0x7fffa34b1a18) at ../../third_party/blink/renderer/core/layout/ng/ng_block_layout_algorithm.cc:357
#3  0x00007fffe2af6b99 in blink::(anonymous namespace)::LayoutWithAlgorithm (node=..., space=..., break_token=0x0) at ../../third_party/blink/renderer/core/layout/ng/ng_block_node.cc:75
#4  0x00007fffe2af576d in blink::NGBlockNode::Layout (this=0x7fffa34b3a80, constraint_space=..., break_token=0x0) at ../../third_party/blink/renderer/core/layout/ng/ng_block_node.cc:269
#5  0x00007fffe2afaa74 in blink::NGBlockNode::LayoutAtomicInline (this=0x7fffa34b3a80, parent_constraint_space=..., parent_style=..., baseline_type=blink::kAlphabeticBaseline, use_first_line_style=false) at ../../third_party/blink/renderer/core/layout/ng/ng_block_node.cc:884
#6  0x00007fffe2d5b9ed in blink::NGLineBreaker::HandleAtomicInline (this=0x7fffa34b47a8, item=...) at ./../../third_party/blink/renderer/core/layout/ng/inline/ng_line_breaker.cc:799
#7  0x00007fffe2d58945 in blink::NGLineBreaker::BreakLine (this=0x7fffa34b47a8) at ./../../third_party/blink/renderer/core/layout/ng/inline/ng_line_breaker.cc:281

Under some circumstances we enter a block of code that just resolves the inline length for fit-content, but doesn't explicitly clamp to min-inline-size and max-inline-size. The code seems to rely on the min/max values stored in legacy being clamped to min-inline-size and max-inline-size, but this isn't the case if those values were percentage-based. Or something like that.

Deleted: tc.html 285 bytes

tc.html 285 bytes View Download

Reduction that doesn't depend on inline layout.

Deleted: tc2.html 249 bytes

tc2.html 249 bytes View Download

Thank you Morten!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/09554587ea7aeaccea14eb54a95660f4e369c7ad

commit 09554587ea7aeaccea14eb54a95660f4e369c7ad
Author: Morten Stenshorne <mstensho@chromium.org>
Date: Wed Dec 05 06:50:44 2018

[LayoutNG] Honor {min,max}-inline-size when using cached intrinsic size.

We store cached min/max intrinsic inline sizes in legacy layout objects.
These are normally constrained against {min,max}-inline-size, but not
if those values are percentage based, since percentages are obviously
not resolvable at the time of calculating intrinsic sizes. In such cases
we cannot use the cached values directly. Calculate intrinsic size and
apply constraints on our own in such cases.

Bug:  900390 
Change-Id: I90b8ab590fa97e8ec7929bc1af38cf3824f9ea6b
Reviewed-on: https://chromium-review.googlesource.com/c/1360853
Reviewed-by: Koji Ishii <kojii@chromium.org>
Reviewed-by: Aleks Totic <atotic@chromium.org>
Reviewed-by: Christian Biesinger <cbiesinger@chromium.org>
Commit-Queue: Morten Stenshorne <mstensho@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613889}
[modify] https://crrev.com/09554587ea7aeaccea14eb54a95660f4e369c7ad/third_party/blink/renderer/core/layout/ng/ng_length_utils.cc
[add] https://crrev.com/09554587ea7aeaccea14eb54a95660f4e369c7ad/third_party/blink/web_tests/external/wpt/css/css-sizing/percentage-min-width.html