Support for XML 1.1 schema files

[sreejithsree139]

I am converting my epub file URL to stream and saving to local DB as bytes like below:

Stream stream;
HttpClient client = new HttpClient();
var response = await client.GetAsync(fileUrl);
stream = await response.Content.ReadAsStreamAsync();
epubBook = EpubReader.ReadBook(stream);

//saving to folder
byte[] bytes = await response.Content.ReadAsByteArrayAsync();
string filename = Path.GetFileName(fileUrl);
var folderPath = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
var filePath = Path.Combine(folderPath, filename);
File.WriteAllBytes(filePath, bytes);

This is working fine for most of the files. But some file URLs showing System.AggregateException.

Exception Details

System.AggregateException: One or more errors occurred. (Version number '1.1' is invalid. Line 1, position 16.) ---> System.Xml.XmlException: Version number '1.1' is invalid. Line 1, position 16.
at System.Xml.XmlTextReaderImpl.Throw (System.Exception e) [0x00027] in <0757e7484a1349cca3b4558c721885b2>:0
at System.Xml.XmlTextReaderImpl.Throw (System.String res, System.String arg) [0x00029] in <0757e7484a1349cca3b4558c721885b2>:0
at System.Xml.XmlTextReaderImpl.ParseXmlDeclaration (System.Boolean isTextDecl) [0x0061f] in <0757e7484a1349cca3b4558c721885b2>:0
at System.Xml.XmlTextReaderImpl.Read () [0x000c6] in <0757e7484a1349cca3b4558c721885b2>:0
at System.Xml.Linq.XDocument.Load (System.Xml.XmlReader reader, System.Xml.Linq.LoadOptions options) [0x00016] in <89374192b20a41739cf7c5bb822846fe>:0
at System.Xml.Linq.XDocument.Load (System.IO.Stream stream, System.Xml.Linq.LoadOptions options) [0x0000f] in <89374192b20a41739cf7c5bb822846fe>:0
at System.Xml.Linq.XDocument.Load (System.IO.Stream stream) [0x00000] in <89374192b20a41739cf7c5bb822846fe>:0
at VersOne.Epub.Internal.XmlUtils+<>c__DisplayClass0_0.b__0 () [0x00000] in <7c46dbfe3ebf403389304a938822832e>:0
at System.Threading.Tasks.Task`1[TResult].InnerInvoke () [0x0000f] in <46c2fa109b574c7ea6739f9fe2350976>:0
at System.Threading.Tasks.Task.Execute () [0x00000] in <46c2fa109b574c7ea6739f9fe2350976>:0
--- End of stack trace from previous location where exception was thrown ---

Sample file URLs having this issue:

https://s3.us-east-1.amazonaws.com/catholic-brain/prod/dc/cbrain-app/files/doc-lib/2020/08/10/12/56/42/068/head/9781612781495_EPUB.epub

https://s3.us-east-1.amazonaws.com/catholic-brain/prod/dc/cbrain-app/files/doc-lib/2020/08/10/07/36/06/376/head/9781612781358_EPUB.epub

I am using EpubReader.Cross Nuget for parsing the epub file.

I have uploaded a sample project for the easy reference.

[vers-one]

Yeah, .NET doesn't support XML 1.1 due to its low popularity and lack of widespread adoption. This pull request should provide a workaround for a majority of the cases and the pull request mentioned by @yunusefendi52 above should make this workaround more robust.

[vers-one]

Looks like the easiest solution would be just to skip the XML header completely before passing the stream to the XDocument.

Implemented in PR #50.