Created attachment 182861 [details] Example using NotoNastaliqUrdu font Description: Nastaliq fonts, for example "Noto Nastaliq Urdu" and "IranNastaliq" are different from Normal Arabic/Persian/Urdu fonts in the way Kashidas are implemented. This example uses "Noto Nastaliq Urdu" font which does not use kashida at all. IranNastaliq font works with kashida, but they are implemented as ligatures. Using the horizontal lines as kashidas with Nastaliq fonts causes rendering defects. Steps to Reproduce: 1. Install NotoNastaliqUrdu font 2. Open the example file Actual Results: Bad black lines are visible in the output. Kashida is not suitable for Nastaliq font. Expected Results: No black lines should be visible in the output. Also, the spacing of the characters should not be very big. Reproducible: Always User Profile Reset: No Additional Info: Reproduced with the LO 7.4: Version: 7.4.0.3 / LibreOffice Community Build ID: f85e47c08ddd19c015c0114a68350214f7066f5a CPU threads: 8; OS: Linux 5.15; UI render: default; VCL: gtk3 Locale: en-US (en_US.UTF-8); UI: en-US Calc: threaded The "NotoNastaliqUrdu" font can be downloaded from the fonts-noto-core package on Ubuntu 22.04: https://packages.ubuntu.com/jammy/fonts-noto-core
Created attachment 182862 [details] Example using NotoNastaliqUrdu font (PDF) The bad horizontal black lines are visible in the PDF output
Created attachment 182866 [details] Example using NotoNastaliqUrdu font with LO 7.5 dev master (PDF) This is the PDF output using NotoNastaliqUrdu font using LO 7.5 dev master. In this example, the bad black lines went away, but the exaggerated space is there. This is because in LO 7.5 dev master, rendering of bad kashidas are avoided, but then the big gaps will be visible in the output. Version: 7.5.0.0.alpha0+ / LibreOffice Community Build ID: d23b1d0240e8ca4a33fbd4fcd368c4ece7b8866a CPU threads: 8; OS: Linux 5.15; UI render: default; VCL: gtk3 Locale: en-US (en_US.UTF-8); UI: en-US Calc: threaded
Created attachment 182867 [details] Example using NotoNastaliqUrdu font creating visible gaps with LO 7.5 This is the nastaliq2.odt file used to generate the above PDF output.
The enlarged spacing is all we can do with the current Kashida insertion method which happens after shaping (so the font has no input on it). Addressing this properly is a much bigger issue and it might involve changes to the OpenType format and/or the OpenType shaping engine we use (HarfBuzz).
Any of this wouldn’t help Noto Nastaliq Urdu since it does not have Kashida it all, so the big spacing is how it is expected to be justified.
(In reply to خالد حسني from comment #5) > Any of this wouldn’t help Noto Nastaliq Urdu since it does not have Kashida > it all, so the big spacing is how it is expected to be justified. Ok, then can you provide the commit in which the fix is provided, and close this bug as FIXED? I can discuss the problem with the big space in another bug report.
Fixed in https://git.libreoffice.org/core/+/9a6b673699fa925f5d87e47d4b359f37ad27260e