Document Deployment Fails

Summary

Deploying Documents via the CLI fails with the message The DocumentFolder named Folder_Name/Document_Name was not found in the workspace.

Steps To Reproduce:

1. Ensure a Document Folder named MyFolder exists in the source environment, with a Document named MyDocument.txt inside.
2. Using the following package.xml, perform a force:source:retrieve

<?xml version="1.0" encoding="UTF-8"?>
<Package xmlns="http://soap.sforce.com/2006/04/metadata">
  <types>
    <name>Document</name>
    <members>MyFolder</members>
    <members>MyFolder/MyDocument.txt</members>
  </types>
  <version>46.0</version>
</Package>

1. Using the same manifest, attempt to deploy the Document and Folder.

Expected result

The Document and Folder were deployed.

Actual result

You receive the error message The DocumentFolder named MyFolder/MyDocument.txt was not found in the workspace.

Additional information

Feel free to attach a screenshot.

SFDX CLI Version(to find the version of the CLI engine run sfdx --version): 7.15.3

SFDX plugin Version(to find the version of the CLI plugin run sfdx plugins --core): 46.6.0

OS and version: Windows 10 Pro

[clairebianchi]

If you remove the file extension (.txt) it should work. Deploy does not take the file extension

[mshanemc]

is fixed.