underscore (U+005F) not visible in .pdf when using TTF

[theovanh]

Underscore (ascii 5F) is not visible when a document in Word 2007 is saved as .pdf Other fonts do not have this problem. The character '5F' is present in the .pdf but not visible. Windows 10.

[frankrolf]

That’s odd. Which version of the font are you using? OTF or TTF?
At first glance it looks similar to this problem: adobe-fonts/source-sans#154

Would like to get to the bottom of this, but I don’t know if there’s anything one can do in the font files. Please try the TTF if you are using OTF, and vice versa.

[frankrolf]

How is the PDF generated? You may want to try using the Adobe PDF “printer”:
https://helpx.adobe.com/acrobat/using/print-to-pdf.html

[theovanh]

I made the .pdf by Save as… in Word 2007. So it is a Word document saved by the pdf-save function in Word 2007. Striking is that the omission of the display of the underscore (ascii 5F) only happens with the Source Serif Pro font as demonstrated by the example that I attached. I am disappointed because I like the font very much. As I explained, the character is actually present in the .pdf. This is demonstrated by selecting a piece of text in the .pdf , then copy and paste into Notepad where the underscore shows up. Opening the .pdf with Firefox, Chrome, MS Edge makes no difference. None of these shows the underscore, not with Source Serif Pro or Source Serif Pro Semibold. There must be something in the code of the font. I do hope , this bug can be removed. Success, hope to hear from you, Theo van Herwijnen

[theovanh]

Frank, Quick answer: I use the TTF. Tomorrow I will test the OTF. Regards, Theo

[theovanh]

The font file is version 2.007; hotconv 1.0.1.08;makeotfexe 2.5.65593.
I believe the problem is rather with the Reader Reader XI, version 11.0.23. Upgraded to Reader DC 2019.010.20064 and repeated the exercise : underscore is carried through into Notepad but not shown in Reader DC:

[frankrolf]

@theovanh Would you mind trying to write the PDF in another way – not through “save as…” but using the Adobe PDF printer. I’d be curious to know the result here.

[theovanh]

I do not have the Acrobat virtual printer available. I printed with 'cutePDFWriter' which gave me a .pdf where the underscores are visible in Reader DC. When 'printed' from Word with 'Microsoft Print to PDF' the result did NOT show the underscore of Source Serif Pro but copy/paste into Notepad demonstrated that they are present (as in the test above). Probably the 'MS Print to PDF' uses the same function as its 'Save as ..'
Conclusion: the problem is caused by the Word 2007 PDF software which makes Reader DC refuse to show the 5F underscore in font Source Serif Pro.

[theovanh]

Frank, Good morning. I posted on github my latest findings. Attached the 2 pdf’s. I noticed that there are significant differences in the Properties/Fonts of the 2 pdf’s. Succes, Theo

[frankrolf]

Dear Theo, happy new year!
Unfortunately I did not personally receive the PDFs you promised (all messages are re-routed through GitHub and attachments removed)
Could you please send them again directly at fgriessh@adobe.com – thank you!

[frankrolf]

Also reproduced, analog to adobe-fonts/source-sans#154 (comment):

Step-by-step:

• install Source Serif Pro Regular 2.007 TTF
• create new Word document in MS Word 2016 on Windows 10.
• paste the text Function __construct($first_name, $last_name)

option 1

File → Save as… → PDF
result: underscores are missing from PDF

option 2

File → Print → Microsoft Print to PDF
result: underscores are missing from PDF

option 3

File → Save as Adobe PDF …
no text whatsoever in PDF

workaround

All above options work properly when using the equivalent OTF font.

[miguelsousa]

Found the problem by using MS Font Validator. The maxComponentElements value in the maxp table is set to zero (instead of 3).

This was caused by an oversight in the ttfcomponentizer adobe-type-tools/afdko#710

[miguelsousa]

Fixed in this release https://github.com/adobe-fonts/source-serif-pro/releases/tag/2.010R-ro%2F1.010R-it