Created attachment 106693 [details]
pdf export of the sample file in Word 2007

The author of the document stated that they created these hand writing objects using a Windows PC tablet with active digitizer pen, but that this could also be achieved with any touch screen using Word's pen tools.

tested under Win7x64
DocX reader 1.0 can read the file which is shown as blank in LibO 4.4.0.0+ master, 4.3.2.2 

I tested older releases and I can tell that image looks almost fine in 3.6.6.2, then image starts disappearing in 3.6.7.2 and is definitively gone in 4.0.4.2 (I don't have early 4.0.x releases to test)

here's the list of bugfixes in 3.6.7.2:
https://wiki.documentfoundation.org/Releases/3.6.7/RC1
https://wiki.documentfoundation.org/Releases/3.6.7/RC2

maybe we can see something suspect that caused the regression

Created attachment 108136 [details]
3.6.6.2 vs 3.6.7.2 screenshot

Thanks for checking older versions as that didnt come to mind when i filed this one. Just assumed it never was able to render it. :)

bibisected:

3c257431da2650bf0d4ca7460af1b082c773816d is the first bad commit
commit 3c257431da2650bf0d4ca7460af1b082c773816d
Author: Bjoern Michaelsen <bjoern.michaelsen@canonical.com>
Date:   Wed Nov 27 14:49:38 2013 +0000

    source-hash-1581b1fc3ac82a7bd62df968226e98604a4ca52d
    
    commit 1581b1fc3ac82a7bd62df968226e98604a4ca52d
    Author:     Miklos Vajna <vmiklos@collabora.co.uk>
    AuthorDate: Mon Nov 25 17:24:39 2013 +0100
    Commit:     Miklos Vajna <vmiklos@collabora.co.uk>
    CommitDate: Mon Nov 25 17:32:36 2013 +0100
    
        CppunitTest_sw_ooxmlexport: make it possible to use ..._TEST_ONLY with -Werror
    
        Change-Id: I451f81495a8e8535c8e0194198602ee5732164c6

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:100644 100644 d0fcf4dc73a5a91def3e71fad9035807fbe84906 34c3ffcb2c754173b10dd0b1766dc5e2daecf91e M	commitmsg
:100644 100644 95386163339b3b232c8b0232a7d819ff40328f91 60671c4bff3b778b99dccbb9ca02b6d06a34b333 M	make.log
:040000 040000 8758436160d305aca069f7ba2a13436b30690d61 3a872c6b5794222bcd89d77b1ee2c7f6f75cac7d M	opt

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The behaviour appears to have changed across the below two commits

Adding Cc: to kendy@collabora.com. Could you possibly take a look at this? Thanks


commit 9d3c0aa1e64ae97ddc305df3873f977051f0b317
Author: Jan Holesovsky <kendy@collabora.com>
Date:   Wed Nov 20 21:17:50 2013 +0100

    Related fdo#61272: Revert "wmf-mm-text.diff: Fix WMF rendering, n#417818"
    
    This approach to WMF breaks EMF reading, need to revert it, and fix a
    different way.
    
    This reverts commit db1b08d217ebbdd1b0296e1da260bf314a77acf5.
    
    Conflicts:
        vcl/source/filter/wmf/winmtf.cxx
        vcl/source/filter/wmf/winmtf.hxx
    
    Change-Id: I8f779791153f2e1faa086c91b82b3e8b93304f3b

commit 198b17dc5e182dfb2e5c930458764c7b3e6c914f
Author: Jan Holesovsky <kendy@collabora.com>
Date:   Wed Nov 20 21:11:24 2013 +0100

    Related fdo#61272: Revert "wmf-mm-text-1.diff: Fix WMF rendering, n#417818"
    
    This approach to WMF breaks EMF reading, need to revert it, and fix a
    different way.
    
    This reverts commit 16eaa5e7c1208034bb3244fea9e6d9491ccb5501.
    
    Conflicts:
        vcl/source/filter/wmf/winmtf.cxx
    
    Change-Id: I59076d0a65d91ba3a1f3ebb48d8f7a542859d351

The Beziers in some of the embedded EMFs have 12 points! That's just not possible, because the number of points must be:

(number of curves x 3) + 1

As per the spec in [MS-EMF], see section 2.3.5.17.

Whether that is the issue, I don't know. But it does tend to indicate some issues with the EMF file, however we should actually just detect this and ignore the extraneous points in the Bezier.

Oh, I see. After that record there is a close figure record. Good to know about this, because I'll quote what Microsoft say in their own documentation about MS-EMF:

  2.3.5.17 EMR_POLYBEZIER16 Record

  Count (4 bytes): A 32-bit unsigned integer that specifies the total number of
  points. This value MUST be one more than three times the number of curves to be
  drawn, because each Bezier curve requires two control points and an endpoint,
  and the initial curve requires an additional starting point.

They neglected to mention that if you have this close figure record directly after then it acts as the extra point they mentioned - you need to use the first point as the end-point.