Major When normalizing filenames, it's useful to replace also all "ß" with "ss". You will also get into trouble with the danish dish Smørrebrød 
The Form.NFKD also replaces some ligatures like ffi (which is normally not needed )
Here's the patch:
diff -r 9b0040cc8b9c src/main/java/org/olat/core/util/FileUtils.java --- a/src/main/java/org/olat/core/util/FileUtils.java Fri Jan 23 11:47:14 2015 +0100 +++ b/src/main/java/org/olat/core/util/FileUtils.java Mon Jan 26 14:29:37 2015 +0100 @@ -840,7 +840,10 @@ nameFirstPass = nameFirstPass.replace("\u00E4", "ae"); nameFirstPass = nameFirstPass.replace("\u00F6", "oe"); nameFirstPass = nameFirstPass.replace("\u00FC", "ue"); - String nameNormalized = Normalizer.normalize(nameFirstPass, Normalizer.Form.NFD).replaceAll("\\p{InCombiningDiacriticalMarks}+",""); + nameFirstPass = nameFirstPass.replace("\u00DF", "ss"); + nameFirstPass = nameFirstPass.replace("\u00F8", "o"); + nameFirstPass = nameFirstPass.replace("\u00E6", "ae"); + String nameNormalized = Normalizer.normalize(nameFirstPass, Normalizer.Form.NFKD).replaceAll("\\p{InCombiningDiacriticalMarks}+",""); String nameSanitized = nameNormalized.replaceAll("\\W+", ""); return nameSanitized; }
