Bug 41015 added non-break spaces before percent signs in French. This is great, but I noticed it would be useful to insert it in more cases: we need non-break spaces between numbers and units (currency signs and unit abbreviations). For currency signs, they can be detected from the Unicode spec. A list is available at http://unicode.org/charts/PDF/U20A0.pdf. For example, in libICU, the type U_CURRENCY_SYMBOL identifies them. For unit abbreviations, Wikipedia has a quite complete list for French at http://fr.wiktionary.org/wiki/Annexe:Unit%C3%A9s_de_mesure_en_fran%C3%A7ais We may also include only the handful of most common units, if that's easier and less error-prone.
Definitely an enhancement request → changed Importance field. Valid, therefore set Status to NEW. NB that at least part of this request does not only apply to French, but also to other languages; e.g., in German it would be nice to have a NBSP in "EUR 13,42", "17 cm" or "5,2 m" etc. automatically. But IMHO this new feature, if added, must be * optional * configurable because you can not force all users to have the same personal style here, not even when distinguishing by languages.
Sure, this kind of language-specific feature/option already exists in AutoCorrection, e.g. for smart quotes or non-break space before %, ?, ; and ! in French.
*** Bug 111982 has been marked as a duplicate of this bug. ***