This is only reproducible when the Run contains an empty string. If the paragraph is empty or the Run contains a space, everything is working correctly.

Workaround: Remove all empty runs from the document.

This is done due to wrong column widths weights calculations.

Implement support for content controls (a.k.a. Structured document tags), which will allow inserting editing controls in the document:

- Rich Text
- Plain Text
- Check Box
- Combo Box
- Drop-down list
- Date picker

Do not confuse this feature with form fields support (see https://feedback.telerik.com/Project/184/Feedback/Details/219850 ).

At this point the PdfFormatProvider does not support floating images and these elements are skipped when exporting to PDF.

The feature is trivial for floating images with "Behind Text"/"In Front of Text" settings, but otherwise floating images are affecting the text layout in complex ways.

These file formats are very similar to DOCX, and can be easily imported with loss of some information (e.g. macros).

ArgumentException with 'Invalid value' message is thrown when importing invalid font sizes from docx, e.g.

<w:sz></w:sz> 

(the 'val' attribute should be specified according to the OOXML specification).

Instead, such documents could be imported as the w:sz is not specified, similar to the behavior of MS Word.

Add support for smart tags (described in the OOXML using the smartTag element). As currently smart tags are not supported, the content inside them is not imported from docx.

Now headings are imported with default heading styles.

Introduce an option for Heading styles to be exported as <h1> - <h6> tags. Consider whether this should be the default behavior, because MS Word exports Headings with H tag and additionally adds styling so the resulting HTML will visually look the way it does in MS Word.

When paragraphs in list and with hanging indent set are imported from RTF, unexpected values for hanging indent and left indent are imported. The problem is most visible when the document is exported to HTML and visualized in browser, as bullets of the list appear over the content.

Support for table styles with different properties for first/last row and column, row bandings.

When importing from HTML, all successive spaces in a spans are trimmed. Instead, in some cases one space should be left, e.g. between words. For example, the importing the following HTML should leave one space after the hyperlink:

<p><a href="www.telerik.com" target="_blank"><span>test</span></a>      and more.</p>

Workaround: After importing, check if the runs after the hyperlinks start with space:
foreach (var hyperlinkEnd in this.document.EnumerateChildrenOfType<FieldCharacter>().Where(f => f.FieldCharacterType == FieldCharacterType.End))
{
    Paragraph currentParagraph = hyperlinkEnd.Paragraph;
    int indexOfNextRun = currentParagraph.Inlines.IndexOf(hyperlinkEnd) + 1;
    if (currentParagraph.Inlines.Count > indexOfNextRun)
    {
        Run run = currentParagraph.Inlines[indexOfNextRun] as Run;
        if (run != null && run.Text[0] != ' ')
        {
            run.Text = " " + run.Text;
        }
    }
}

Implement nested mail merge and master-detail scenario.

There should be an option allowing users to embed fonts in their documents.

Seems to be applicable for DOCX and RTF, MS Word has such option in File -> Options -> Save.

When importing a simple table from HTML in Ms Word, it gets applied table cell spacing and margin. This makes it look more in the manner it does in a browser, i.e. the content of cells is vertically centered.

Check for TableCell, TableRow, and Table.

Hyperlinks should support this property in order to describe where they should be opened (in the same frame/tab or in a new one). It is described in the OOXML specification as tgtFrame (Hyperlink Target Frame). It will be useful for setting the target as _blank.

Introduce new section properties which are responsible for defining columns in the section.

When a style doesn't have explicitly defined font, the font from the default character properties (\defchp) is used when present. Instead, the font used for the style should be the default font for the document, defined with \deffN tag.
The same issue occur when the doesn't contain \defchp at all. In this case, the font for the style is not imported, but instead the defined with  \deffN tag should be used.

The construction is not common, and MS Word for example doesn't produce such documents.

This feature includes: table of figure, table of tables etc.

TOC field contains PageRef fields inside it. To update it, we will need pagination (layout) support and PageRef fields implementation. Also TOC update can be influenced by TC fields presence in the document.

Implement export to PDF.

Extend the support for em units. Em is calculated relatively to the font-size style property.