Markdown ignores empty table cells

[gektor-de]

Description

When pasting markdown tables with empty cells, those cells are being ignored.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://www.tablesgenerator.com/markdown_tables
2. Generate a table or use the following example:

|   |      | Text  |       |      |
|---|------|-------|-------|------|
|   |      |       |       | Text |
|   | Text |       |       |      |
|   |      | Text1 | Text2 |      |

This should render to:

		Text
				Text
	Text
		Text1	Text2

3. Copy and paste to an empty Gutenberg page or post
4. See error:
   

Expected behavior

Tables should be parsed from markdown correctly, as they do for example in github or gitlab environments.

Desktop

• Browser: Tested in latest Chrome and Firefox

Additional context

• Gutenberg Version: 4.1.1

[designsimply]

Tested and confirmed the results of the test based on the steps provided using WordPress 4.9.8 and Gutenberg 4.2.0-rc.1 with Firefox 63.0 on macOS 10.13.6.

I also tested the table example on a few different markdown preview sites such as https://dillinger.io/ and https://markdown-it.github.io/ and https://markdownlivepreview.com/ and found that the table was process correctly in 2 of the 3.

[GlennMartin1]

This bug makes the Table block unusable at this point.

I have Google Sheets tables that include occasional blank cells, and pasting it makes a mess.

[imsimond]

I'm seeing the same problem when copying an HTML table containing empty <td></td> cells from a web page into a Gutenberg block. See also #8953

Original HTML markup of a simple page:

Renders successfully in browser (here, Chrome 71 on Mac):

Copied and pasted into Gutenberg (here, WP 5.0.2):

'Edit as HTML' view within Gutenberg shows the empty cell has been removed:

Verified in both Chrome and Firefox.