Created attachment 202997 [details] Comparison screenshot (Word vs. Writer) Open attachment 161378 [details] from bug 133479. The font is set to Times, which doesn't specify a font, but in Word it is substituted as Times New Roman. In Writer, on a Windows machine, which has Times New Roman, it is not substituted with that font, but with Liberation Serif. The expectation is that if the same substitution font is available, Writer should use the same as Word. Not sure what happens in Linux, I'm tentatively marking this as all platforms, but it can be adjusted if someone has a different experience (provided it is installed, there might be a package for it, like ttf-mscorefonts-installer in Ubuntu). Observed in LO Version: 26.2.0.0.alpha0+ (b24d9ab858a142b806822ba038d3173d35589626) & 4.2.0.4 / Windows. OK in LO 4.1.0.4, Times New Roman is substituted there. Marking as regression, but it needs to be bibisected in Linux, if the bug is reproducible there.
Created attachment 202998 [details] Reference PDF exported from Word (wrong file uploaded)
Created attachment 202999 [details] Reference PDF exported from Word
I disagree. The idea that we must provide the same unspecified substitution lookup algorithm as Word is practically impossible. Maybe implementing/improving PANOSE support could *somewhat* improve this - but in general, I don't believe in "the expectation is that if the same substitution font is available, Writer should use the same as Word". Missing font is, by definition, "you can't expect anything about fonts used, and layout resulting".
Additionally, Liberation Serif is the font that is metrically compatible with Times New Roman (https://en.wikipedia.org/wiki/Liberation_fonts). Substituting Times with Liberation Serif seems *much* better, because (1) it is consistent cross-platform, and (2) it produces the same layout, so should not differ from Word (that uses TNR) in that regard. The shape of glyphs here is immaterial anyway, because we speak about the missing font.
This isn't exactly a case of missing font, but when only a font family is specified. There's some handling of this in MSO/Windows (also mentioned in bug 113007, focusing on the configurability aspect), but I'm not sure of the extent. When a file is saved in OOXML/binary MS format, the likely reason is that at some point in its life it's expected to be opened/edited in Office, or some other office product trying to be compatibly with Office. Writer can try showing the same font as Office, and be cross-platform as well, provided the same font is installed on the system, which is reasonable in this case. Of course if Times New Roman isn't available, it's best to fall back to the next option. And ultimately, Writer can do its own, independent fallback mechanism in ODF format.