Bug 113141 - RTL: Diacritics appear with dotted circle
Summary: RTL: Diacritics appear with dotted circle
Status: RESOLVED NOTABUG
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: LibreOffice (show other bugs)
Version:
(earliest affected)
4.3.7.2 release
Hardware: All All
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords: bibisectRequest, regression
Depends on:
Blocks: RTL-CTL
  Show dependency treegraph
 
Reported: 2017-10-15 19:54 UTC by Yousuf Philips (jay) (retired)
Modified: 2017-10-19 11:52 UTC (History)
2 users (show)

See Also:
Crash report or crash signature:


Attachments
4.2 vs Master (93.37 KB, image/png)
2017-10-15 19:54 UTC, Yousuf Philips (jay) (retired)
Details

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Description Yousuf Philips (jay) (retired) 2017-10-15 19:54:51 UTC
Created attachment 137000 [details]
4.2 vs Master

steps:
1. open writer
2. Insert > Special Character
3. select a font that has arabic (e.g. Simplified Arabic) or hebrew (e.g. Liberation Serif)
4. find arabic diacritic (e.g. U+64B) or hebrew diacritic (e.g. U+5BC)
5. notice dotted circle
6. close dialog
7. switch to arabic or hebrew keyboard layout
8. type ُ  and notice the dotted circle also appears

Regression introduced in the 4.3 cycle.

Version: 6.0.0.0.alpha0+
Build ID: 8eacd3be08bf6e1a97900624611822de9b00a379
CPU threads: 2; OS: Linux 4.4; UI render: default; VCL: gtk2; 
Locale: en-US (en_US.UTF-8); Calc: group
Comment 1 Lior Kaplan 2017-10-15 20:01:52 UTC
Verified in 5.4 and master.
Comment 2 Maxim Monastirsky 2017-10-15 20:22:33 UTC
https://en.wikipedia.org/wiki/Dotted_circle

I believe it's a standard behavior. Can be seen also in Windows in Character Map or Notepad.
Comment 3 Regina Henschel 2017-10-15 21:07:43 UTC
The dotted circle is displayed, if the diacritic is not combined with a letter, for example if it is the only letter in a line or if you have used the wrong order. To combine, you need to first enter the basis letter and then the diacritic.

What code point is the ُ   ?
Comment 4 Yousuf Philips (jay) (retired) 2017-10-15 22:19:40 UTC
(In reply to Maxim Monastirsky from comment #2)
> https://en.wikipedia.org/wiki/Dotted_circle
> 
> I believe it's a standard behavior. Can be seen also in Windows in Character
> Map or Notepad.

Some fonts have it, while other fonts dont, and i do see a benefit of showing it like so in the special character dialog, but dont see a usefulness in a document. I doesnt appear when i type in my browser.

@Khaled: What's your take?

(In reply to Regina Henschel from comment #3)
> What code point is the ُ   ?

U+64F [ARABIC DAMMA]
Comment 5 Khaled Hosny (inactive) 2017-10-16 03:08:44 UTC
That is by design. If a combining mark is at the start of the text, it is displayed over a dotted circle since a combining mark needs something to combine with. You can put a space or no breaking space before the mark if the dotted circle is undesired.
Comment 6 Yousuf Philips (jay) (retired) 2017-10-18 18:57:35 UTC
(In reply to Maxim Monastirsky from comment #2)
> I believe it's a standard behavior. Can be seen also in Windows in Character
> Map or Notepad.

Not there in Gnome's character map (attachment 136982 [details]), KCharSelect or character map sections of font management apps i've seen on Mac, so guess it isnt a standard.
Comment 7 Maxim Monastirsky 2017-10-18 23:04:07 UTC
(In reply to Yousuf Philips (jay) from comment #6)
> Not there in Gnome's character map (attachment 136982 [details]),
> KCharSelect or character map sections of font management apps i've seen on
> Mac, so guess it isnt a standard.
Dotted circle is not only used for diacritics in the official Unicode charts, but also suggested as an implementation in the Unicode standard. See chapter 5, section 5.13 Rendering Nonspacing Marks, under "Fallback Rendering". See also Microsoft's notes at [1] (under "Handling Invalid Combining Marks"). So it's clearly supposed to be shown in the text (but not necessarily have to be shown in a charmap app).

(In reply to Khaled Hosny from comment #5)
> That is by design. If a combining mark is at the start of the text, it is
> displayed over a dotted circle since a combining mark needs something to
> combine with. You can put a space or no breaking space before the mark if
> the dotted circle is undesired.
Isn't it against the referenced Unicode standard, as it says that if a nonspacing mark occurs as the first character in the text, it should be handled as if it had a no-break space before it?

[1] https://www.microsoft.com/typography/OpenTypeDev/arabic/intro.htm#shape
Comment 8 Khaled Hosny (inactive) 2017-10-19 11:52:40 UTC
(In reply to Maxim Monastirsky from comment #7)
> (In reply to Khaled Hosny from comment #5)
> > That is by design. If a combining mark is at the start of the text, it is
> > displayed over a dotted circle since a combining mark needs something to
> > combine with. You can put a space or no breaking space before the mark if
> > the dotted circle is undesired.
> Isn't it against the referenced Unicode standard, as it says that if a
> nonspacing mark occurs as the first character in the text, it should be
> handled as if it had a no-break space before it?

You will need to raise that with HarfBuzz developers where this behavior is implemented.