System.Text.GetEncodings() not complete? Code pages 5xxxx missing in GetEncodings()

[redflitzi]

Hi,

not sure whether this should be an issue, or if I am just misunderstanding something.

I want to have access to as many encodings as possible, for translating some legacy texts from one encoding to another, or even better to UTF-8.
So I installed System.Text.Encoding.CodePages from Nuget and registered it. Now I can access seemingly all of the supported new encodings, with their codepages and names.

However, when I do the following:

    public static List<int> GetAllValidCodepages() 
    {
        List<int> enclist = [];
        foreach (EncodingInfo ei in Encoding.GetEncodings())
        {
            Encoding e = ei.GetEncoding();
            enclist.Add(e.CodePage);
        }
        return enclist;
    }

I find the resulting list is not complete.
The whole range of 5xxxx (from 50220 to 57011) is missing.

Looking here: https://learn.microsoft.com/de-de/windows/win32/intl/code-page-identifiers
or here: https://learn.microsoft.com/de-de/dotnet/api/system.text.encoding.getencodings

those encodings should be included in the list. But they are missing.

I can "manually" access GetEncoding(50220).WebName, which correctly results in "iso-2022-jp", or GetEncoding(57011).WebName, which gives "x-iscii-pa".
But in the GetEncodings() List they are not present. What does this mean? Should I avoid providing these encodings? Are they somehow "not recommended"?

Then I found this issue: #70573 . That encoding doesn't give the right characters, and will not be fixed any soon.

Now I am not sure how to handle those additional encodings. Are they reliable? Correnctly implemented? Complete? If only some of them, then which ones? Unfortunately I cannot judge or test this.

How can I find out which of the encodings in System.Text.Encoding.CodePages I can use, and which I should avoid?

[redflitzi]

It is even worse.
When I try to run the console printing function in the second URL (GetEncodings() Example Source) it crashes with exception thrown. This example just does not run.

After sorting and comprehensive exception catching (displaying "--------" instead), I now get:

CodePage identifier and name     BrDisp   BrSave   MNDisp   MNSave   1-Byte   ReadOnly 
37     IBM037                    -------- -------- -------- -------- True     True     
437    IBM437                    -------- -------- -------- -------- True     True     
500    IBM500                    -------- -------- -------- -------- True     True     
708    ASMO-708                  -------- -------- -------- -------- True     True     
720    DOS-720                   -------- -------- -------- -------- True     True     
737    ibm737                    -------- -------- -------- -------- True     True     
775    ibm775                    -------- -------- -------- -------- True     True     
850    ibm850                    -------- -------- -------- -------- True     True     
852    ibm852                    -------- -------- -------- -------- True     True     
855    IBM855                    -------- -------- -------- -------- True     True     
857    ibm857                    -------- -------- -------- -------- True     True     
858    IBM00858                  -------- -------- -------- -------- True     True     
860    IBM860                    -------- -------- -------- -------- True     True     
861    ibm861                    -------- -------- -------- -------- True     True     
862    DOS-862                   -------- -------- -------- -------- True     True     
863    IBM863                    -------- -------- -------- -------- True     True     
864    IBM864                    -------- -------- -------- -------- True     True     
865    IBM865                    -------- -------- -------- -------- True     True     
866    cp866                     -------- -------- -------- -------- True     True     
869    ibm869                    -------- -------- -------- -------- True     True     
870    IBM870                    -------- -------- -------- -------- True     True     
874    windows-874               -------- -------- -------- -------- True     True     
875    cp875                     -------- -------- -------- -------- True     True     
932    shift_jis                 -------- -------- -------- -------- False    True     
936    gb2312                    -------- -------- -------- -------- False    True     
949    ks_c_5601-1987            -------- -------- -------- -------- False    True     
950    big5                      -------- -------- -------- -------- False    True     
1026   IBM1026                   -------- -------- -------- -------- True     True     
1047   IBM01047                  -------- -------- -------- -------- True     True     
1140   IBM01140                  -------- -------- -------- -------- True     True     
1141   IBM01141                  -------- -------- -------- -------- True     True     
1142   IBM01142                  -------- -------- -------- -------- True     True     
1143   IBM01143                  -------- -------- -------- -------- True     True     
1144   IBM01144                  -------- -------- -------- -------- True     True     
1145   IBM01145                  -------- -------- -------- -------- True     True     
1146   IBM01146                  -------- -------- -------- -------- True     True     
1147   IBM01147                  -------- -------- -------- -------- True     True     
1148   IBM01148                  -------- -------- -------- -------- True     True     
1149   IBM01149                  -------- -------- -------- -------- True     True     
1200   utf-16                    False    True     False    False    False    True     
1201   utf-16BE                  False    False    False    False    False    True     
1250   windows-1250              -------- -------- -------- -------- True     True     
1251   windows-1251              -------- -------- -------- -------- True     True     
1252   windows-1252              -------- -------- -------- -------- True     True     
1253   windows-1253              -------- -------- -------- -------- True     True     
1254   windows-1254              -------- -------- -------- -------- True     True     
1255   windows-1255              -------- -------- -------- -------- True     True     
1256   windows-1256              -------- -------- -------- -------- True     True     
1257   windows-1257              -------- -------- -------- -------- True     True     
1258   windows-1258              -------- -------- -------- -------- True     True     
1361   Johab                     -------- -------- -------- -------- False    True     
10000  macintosh                 -------- -------- -------- -------- True     True     
10001  x-mac-japanese            -------- -------- -------- -------- False    True     
10002  x-mac-chinesetrad         -------- -------- -------- -------- False    True     
10004  x-mac-arabic              -------- -------- -------- -------- True     True     
10005  x-mac-hebrew              -------- -------- -------- -------- True     True     
10006  x-mac-greek               -------- -------- -------- -------- True     True     
10007  x-mac-cyrillic            -------- -------- -------- -------- True     True     
10010  x-mac-romanian            -------- -------- -------- -------- True     True     
10017  x-mac-ukrainian           -------- -------- -------- -------- True     True     
10021  x-mac-thai                -------- -------- -------- -------- True     True     
10029  x-mac-ce                  -------- -------- -------- -------- True     True     
10079  x-mac-icelandic           -------- -------- -------- -------- True     True     
10081  x-mac-turkish             -------- -------- -------- -------- True     True     
10082  x-mac-croatian            -------- -------- -------- -------- True     True     
12000  utf-32                    False    False    False    False    False    True     
12001  utf-32BE                  False    False    False    False    False    True     
20000  x-Chinese-CNS             -------- -------- -------- -------- False    True     
20001  x-cp20001                 -------- -------- -------- -------- False    True     
20002  x-Chinese-Eten            -------- -------- -------- -------- False    True     
20003  x-cp20003                 -------- -------- -------- -------- False    True     
20004  x-cp20004                 -------- -------- -------- -------- False    True     
20005  x-cp20005                 -------- -------- -------- -------- False    True     
20105  x-IA5                     -------- -------- -------- -------- True     True     
20106  x-IA5-German              -------- -------- -------- -------- True     True     
20107  x-IA5-Swedish             -------- -------- -------- -------- True     True     
20108  x-IA5-Norwegian           -------- -------- -------- -------- True     True     
20127  us-ascii                  False    False    True     True     True     True     
20261  x-cp20261                 -------- -------- -------- -------- False    True     
20269  x-cp20269                 -------- -------- -------- -------- True     True     
20273  IBM273                    -------- -------- -------- -------- True     True     
20277  IBM277                    -------- -------- -------- -------- True     True     
20278  IBM278                    -------- -------- -------- -------- True     True     
20280  IBM280                    -------- -------- -------- -------- True     True     
20284  IBM284                    -------- -------- -------- -------- True     True     
20285  IBM285                    -------- -------- -------- -------- True     True     
20290  IBM290                    -------- -------- -------- -------- True     True     
20297  IBM297                    -------- -------- -------- -------- True     True     
20420  IBM420                    -------- -------- -------- -------- True     True     
20423  IBM423                    -------- -------- -------- -------- True     True     
20424  IBM424                    -------- -------- -------- -------- True     True     
20833  x-ebcdic-koreanextended   -------- -------- -------- -------- True     True     
20838  IBM-Thai                  -------- -------- -------- -------- True     True     
20866  koi8-r                    -------- -------- -------- -------- True     True     
20871  IBM871                    -------- -------- -------- -------- True     True     
20880  IBM880                    -------- -------- -------- -------- True     True     
20905  IBM905                    -------- -------- -------- -------- True     True     
20924  IBM00924                  -------- -------- -------- -------- True     True     
20932  EUC-JP                    -------- -------- -------- -------- False    True     
20936  x-cp20936                 -------- -------- -------- -------- False    True     
20949  x-cp20949                 -------- -------- -------- -------- False    True     
21025  cp1025                    -------- -------- -------- -------- True     True     
21866  koi8-u                    -------- -------- -------- -------- True     True     
28591  iso-8859-1                True     True     True     True     True     True     
28592  iso-8859-2                -------- -------- -------- -------- True     True     
28593  iso-8859-3                -------- -------- -------- -------- True     True     
28594  iso-8859-4                -------- -------- -------- -------- True     True     
28595  iso-8859-5                -------- -------- -------- -------- True     True     
28596  iso-8859-6                -------- -------- -------- -------- True     True     
28597  iso-8859-7                -------- -------- -------- -------- True     True     
28598  iso-8859-8                -------- -------- -------- -------- True     True     
28599  iso-8859-9                -------- -------- -------- -------- True     True     
28603  iso-8859-13               -------- -------- -------- -------- True     True     
28605  iso-8859-15               -------- -------- -------- -------- True     True     
29001  x-Europa                  -------- -------- -------- -------- True     True     
65000  utf-7                     False    False    True     True     False    True     
65001  utf-8                     True     True     True     True     False    True     

(I also enabled utf-7.)

So it seems that the browser/email info fields are only available for the encodings that are available per default, otherwise an exception is thrown.

And the codepages 38598 and 50220 to 57011 are completely missing and not listed.
Why is this?
What am I doing wrong?