Description: In certain cases and with certain fonts, CTL text subject to font fallback can still produce overlapping glyphs. These appear to be ligatures. Important notes: - The results are sensitive to the specific font used for fallback. You may see large differences by changing the text language or the base font. - This may not reproduce consistently on Windows due to font linking. Steps to Reproduce: 1. Open attachment 202926 [details], a text file containing the endonyms of various languages from Wikipedia. 2. Paste the contents without formatting into Writer. 3. Make sure the Western, Asian, and Complex fonts are all set to something like Noto Sans (not the language-specific subfonts). 4. Note that some of the CTL endonyms are formatted incorrectly (for example, Burmese). 5. Change the font to a language-specific font. For example, change the Burmese text to use Noto Sans Myanmar. 6. Note that the text is now rendered correctly. Actual Results: Certain CTL text is rendered incorrectly due to font fallback. Expected Results: Text should be rendered correctly, even if we have to use font fallback. Reproducible: Always User Profile Reset: No Additional Info: Version: 25.8.1.1 (X86_64) Build ID: 54047653041915e595ad4e45cccea684809c77b5 CPU threads: 12; OS: Linux 6.2; UI render: default; VCL: gtk3 Locale: en-US (en_US.UTF-8); UI: en-US Calc: threaded
I can confirm the issue, but I have to add some notes: 1. Sometimes the issue comes from a defective font. For example, I see such issue for "Free Serif" with Arabic text: tdf#163878 - Wrong rendering of Arabic texts https://bugs.documentfoundation.org/show_bug.cgi?id=163878 2. The problem goes away by setting language to "None" in "Tools > Language > For All Text > None (Do not check spelling)". 3. I remember a similar issue for rendering Arabic text, which was eventually fixed by Caolan, but unfortunately I could not find the issue number. 4. In the end, it makes sense to avoid using fallback font(s) that are not suitable for a piece of text. Version: 25.8.1.1 (X86_64) Build ID: 54047653041915e595ad4e45cccea684809c77b5 CPU threads: 12; OS: Linux 6.2; UI render: default; VCL: gtk3 Locale: en-US (en_US.UTF-8); UI: en-US Calc: threaded
> 3. I remember a similar issue for rendering Arabic text, which was > eventually fixed by Caolan, but unfortunately I could not find the issue number This is the above mentioned issue: tdf#152196 - Visible gaps in Arabic/Persian text with fallback font https://bugs.documentfoundation.org/show_bug.cgi?id=152196