text viewer and editor encoding (autodetect) issues

[stuntsman]

Text file autodetecting is still an issue, my report has been misunderstood earlier in #155

The issue is, that only a few codepages are detected/supported, and others are not detected correctly, see Utils.m:

        NSStringEncoding encodes[] = {
            NSUTF8StringEncoding,
            CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000),
            CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_2312_80),
            CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGBK_95),
            NSUnicodeStringEncoding,
            NSASCIIStringEncoding,
            0,
        };

For many codepages the autodetect fails and gives wrong result. You can try Windows-1250, Windows-1252, ISO-8859-1, ISO-8859-2 or many others. ISO-8859 codepages are widely used in European countries.

File in Windows-1250 encoding (simple single byte codepage):

Failed autodetect in Seafile:

Originally posted by @stuntsman in #155 (comment)