Created attachment 183563 [details] Diacritics cut off Description: In Arabic script languages like Arabic, Persian, etc., several diacritics are used; some of them are called 'harakat's. These diacritics are placed above or below the characters depending on their type. In the last line of a paragraph, for the font size bigger than 150 with Tahoma font, rendering of diacritics below the characters is cut off. This is incorrect rendering. This problem is limited to the display, as the output is correct, without cut off. Steps to Reproduce: Actual Results: In the first page of attachment, there are 3 paragraphs, each one a single line, containing text with font size 150, 151, and 152 respectively. In this case, the diacritics in the 2 last lines are cut off. In the second page of the attachment, there is only 1 paragraph that is wrapped into 3 lines. The font sizes are equal to the ones in the first page. In this page, only the last line with font size 152 has cut off diacritics. Expected Results: Mo cut off in the diacritics Reproducible: Always User Profile Reset: No Additional Info: Version: 7.5.0.0.alpha0+ (X86_64) / LibreOffice Community Build ID: 75b569890a6630bb2a5b727c8567f7ea59ccb62e CPU threads: 8; OS: Linux 5.15; UI render: default; VCL: gtk3 Locale: en-US (en_US.UTF-8); UI: en-US Calc: threaded For more information about diacritics, One may refer to: * Diacritic https://en.wikipedia.org/wiki/Diacritic#Arabic * Arabic Diacritic https://en.wikipedia.org/wiki/Arabic_diacritics
Created attachment 183564 [details] Diacritics is not cut off (PDF output) The PDF output is OK.
Created attachment 183565 [details] Diacritics cut off (screenshot from the display) The display is wrong, and the diacritics are cut off
confirm with Version: 7.5.0.0.alpha0+ (X86_64) / LibreOffice Community Build ID: cfc8a8f5d841b3f84d207196153be67da7f60652 CPU threads: 4; OS: Linux 5.15; UI render: default; VCL: gtk3 Locale: cs-CZ (cs_CZ.UTF-8); UI: en-US Calc: threaded and Version 4.1.0.0.alpha0+ (Build ID: efca6f15609322f62a35619619a6d5fe5c9bd5a) - in 4.1 it's different.
Not reproducible with LO 3.5: LibreOffice 3.5.0rc3 Build ID: 7e68ba2-a744ebf-1f241b7-c506db1-7d53735 It is important to add that sometimes (but not always) the cut off goes away when tatweel character (ـ) is removed from the text.
For me, checking with the libreoffice-64-releases bibisect repository, the situation really changed at libreoffice-4.1.4.2: - OOo 3.3 > libreoffice-4.1.4.1: display is sometimes wrong for the first paragraph on fileopen, bug zoom changes refresh and correct the view. However, scroll up and down makes diacritic appear cut off. - since libreoffice-4.1.4.2 and still current in recent trunk build: all paragraphs displayed wrong from fileopen; a zoom does no refresh the view anymore. So I see a temporary display issue inherited from OOo, but it's now permanent since 4.1.4.2. Not sure what is relevant in these changes: https://wiki.documentfoundation.org/Releases/4.1.4/RC2#List_of_fixed_bugs (In reply to raal from comment #3) > and Version 4.1.0.0.alpha0+ (Build ID: > efca6f15609322f62a35619619a6d5fe5c9bd5a) - in 4.1 it's different. I assume that's the difference you saw, raal? Khaled, maybe you have an idea?
Sounds like a clipping issue. We have lots of these, and there are many similar bug reports affecting Latin diacritics and other writing systems. It appears that we use the font’s ascender and descender to calculate the clipping box, but they are meant to control line spacing and fonts often has glyphs that go beyond them. I never figured out where is this clipping code, so this is just speculative.
I think we have multiple different bug reports about these clipping issues, but I’m not familiar with this part of LibreOffice, though it feels like somewhere is conflating line height with text extents.