Created attachment 183568 [details] Illustration of gap Sometimes, with Hebrew text in some fonts, the shading of a field exhibits gaps. I also see weird shading shaping when the font size or family changes sometimes, but for the purposes of this bug: Exactly the same font. Seen with: Version: 7.5.0.0.alpha0+ (X86_64) / LibreOffice Community Build ID: 2486d99c6053af1414117faac2c0db18c0d344c4 CPU threads: 4; OS: Linux 6.0; UI render: default; VCL: gtk3 Locale: en-IL (en_IL); UI: en-US and with 7.4.1.2 release on same platform and same VCL.
Created attachment 183569 [details] Document with field exhibiting the gap Note this document uses an uncommon Hebrew font. I'll attach that as well.
Created attachment 183570 [details] Font family used in the sample document
Reproduced in: Version: 7.5.0.0.alpha0+ (X86_64) / LibreOffice Community Build ID: 6e66b5d75b4cda0314b64f4d12ef9e4350751470 CPU threads: 8; OS: Linux 5.15; UI render: default; VCL: gtk3 Locale: en-AU (en_AU.UTF-8); UI: en-US Calc: threaded and Version: 7.4.2.3 / LibreOffice Community Build ID: 382eef1f22670f7f4118c8c2dd222ec7ad009daf CPU threads: 8; OS: Linux 5.15; UI render: default; VCL: gtk3 Locale: en-AU (en_AU.UTF-8); UI: en-US Calc: threaded and Version: 6.3.6.2 Build ID: 2196df99b074d8a661f4036fca8fa0cbfa33a497 CPU threads: 8; OS: Linux 5.15; UI render: default; VCL: gtk3; Locale: en-AU (en_AU.UTF-8); UI-Language: en-US Calc: threaded Looks like it happens at the junction between LTR and RTL. Doesn't happen with text highlighting.
I suspect this is similar to bug 35907 and bug 103643, and bug 77279. I suspect that calculating the text extents to draw the underline or background is using low resolution or has rounding issues, so when the text is more than one portion a gap is shown. Perhaps Caolán McNamara has some idea.
Reproduced in OOo 3.3 as well (although it breaks even more in the number: 2|02|2| נובמבר)
Created attachment 199747 [details] Screenshots from manipulating example document The gap appears due to a 1 pt character spacing applied to the Hebrew word in the sample document. Row 1: The original text. Row 2: The original text, but with all character spacing reset to 0. Row 3: The original text, plus some English text. Note the gaps in the field shading between each English letter. Row 4: The same, but with character spacing reset to 0. Quite mysterious. Field shading with character spacing bridges numbers and RTL text, but not the spaces around bidi portions, and not between LTR letters.