That's a regression. Culprit is:

commit 5e332f1275dd6f4b6d487d313f4db8497df339ab
Author: Dan Sinclair <dsinclair@chromium.org>
Date:   Mon Jan 29 19:52:07 2018 +0000

    Cleanup the FFWidget determination code.
    
    This CL converts the UIType to an XFA_FFWidgetType instead of reusing
    the XFA_Element type. The creation code is cleaned up to make it clearer
    what's happening.
    
    Change-Id: I5d3e4967d5c8b8a50dbb25e574b0d31fe0cf407a
    Reviewed-on: https://pdfium-review.googlesource.com/24390
    Reviewed-by: Ryan Harrison <rharrison@chromium.org>
    Commit-Queue: dsinclair <dsinclair@chromium.org>

Since it's been too long, I'll look into how to fix forward.

The problem is larger than I thought.

I rendered imm5257e.pdf with pdfium_test before and after, with a couple of strategic prints.

Diffing the outputs show that is that some Nodes that were Lines and one node that was a Rectangle are being considered TextEdits after this change.

Look at after.out and see how there are some occurrences of:
"""
pNode->GetFFWidgetType() child->GetElementType() 300
10
"""

300 is XFA_Element::Line, and it used to be interpreted as such in FFNotify::OnCreateContentLayoutItem(), creating a CXFA_FFLine.
Now it's converted (in all but two cases) to 10, which is XFA_FFWidgetType::kTextEdit. In the remaining two cases, it's converted correctly to 12, which is XFA_FFWidgetType::kLine.

This also happens in one instance with XFA_Element::Rectangle, which is 227, being converted to 10 (XFA_FFWidgetType::kTextEdit).

The effect this has is that some lines don't appear, and instead TextEdits are created - I don't know where.

See the rendering differences before and after attached.

I couldn't actually find where the original DateTimeEdit went. My guess is that it's underneath one of these false TextEdits, since I couldn't find discrepancies related to DateTimeEdits.

Deleted: before.out 28.4 KB

before.out 28.4 KB Download

Deleted: after.out 32.2 KB

after.out 32.2 KB Download

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The following revision refers to this bug:
  https://pdfium.googlesource.com/pdfium/+/c732e9aa64a82c06c0ad369088d0481dd2636b86

commit c732e9aa64a82c06c0ad369088d0481dd2636b86
Author: Henrique Nakashima <hnakashima@chromium.org>
Date: Mon May 07 22:44:26 2018

Restore logic of CreateChildUIAndValueNodesIfNeeded().

CreateUIChild() was changed and renamed to
CreateChildUIAndValueNodesIfNeeded() in:
https://pdfium-review.googlesource.com/c/pdfium/+/24390

This caused some bugs but it's too far back for a rollback.

This cl restores the logic of CreateUIChild() keeping the new
signature.

Bug:  chromium:838994 
Change-Id: I44ce741fdb90f8b0fd11379b5e881e376c307f0c
Reviewed-on: https://pdfium-review.googlesource.com/32090
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>

[add] https://crrev.com/c732e9aa64a82c06c0ad369088d0481dd2636b86/testing/resources/pixel/xfa_specific/xfa_rectangle_node.in
[modify] https://crrev.com/c732e9aa64a82c06c0ad369088d0481dd2636b86/xfa/fxfa/parser/cxfa_node.cpp
[add] https://crrev.com/c732e9aa64a82c06c0ad369088d0481dd2636b86/testing/resources/pixel/xfa_specific/xfa_rectangle_node_expected.pdf.0.png

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d0a8df71b3c196e7a8bcb72b639fdcb4f03e88b1

commit d0a8df71b3c196e7a8bcb72b639fdcb4f03e88b1
Author: pdfium-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com <pdfium-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Date: Tue May 08 06:05:07 2018

Roll src/third_party/pdfium/ cb391259a..e5c0fa97c (12 commits)

https://pdfium.googlesource.com/pdfium.git/+log/cb391259aefd..e5c0fa97c2da

$ git log cb391259a..e5c0fa97c --date=short --no-merges --format='%ad %ae %s'
2018-05-08 thestig Make one more CPDF_PageObjectHolder member protected.
2018-05-07 thestig Make more CPDF_PageObjectHolder members protected.
2018-05-07 thestig Make CPDF_PageObjectHolder::m_iTransparency protected.
2018-05-07 thestig Add some getters for CPDF_PageObjectHolder.
2018-05-07 hnakashima Restore logic of CreateChildUIAndValueNodesIfNeeded().
2018-05-07 tsepez Move codepage tables from cpdf_document.cpp to fx_codepage.cpp
2018-05-07 tsepez Use unowned ptr for CPDF_Page::m_pView.
2018-05-07 thestig Move some CPDF_TextPage methods into an anonymous namespace.
2018-05-07 thestig Initialize CPDF_RenderStatus members in the header.
2018-05-07 thestig Initialize CPDF_TextPage members in the header.
2018-05-07 tsepez Ensure that XFA Pages always have a corresponding PDF page
2018-05-07 tsepez Add test for mutltiple copies of same PDF page.

Created with:
  roll-dep src/third_party/pdfium
BUG= chromium:838994 


The AutoRoll server is located here: https://pdfium-roll.skia.org

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.


TBR=dsinclair@chromium.org

Change-Id: I383e6d0de113818b5481784c690c62aa213fb394
Reviewed-on: https://chromium-review.googlesource.com/1049111
Reviewed-by: pdfium-chromium-autoroll <pdfium-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Commit-Queue: pdfium-chromium-autoroll <pdfium-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#556706}
[modify] https://crrev.com/d0a8df71b3c196e7a8bcb72b639fdcb4f03e88b1/DEPS