Demo content: paste not working properly after selecting all blocks

[phpbits]

Describe the bug
There's a bug when it comes to pasting. It's not working when you select the first paragraph to when pasting.

To reproduce
Steps to reproduce the behavior:

1. Go to Gutenberg > Demo
2. On the menu & tools option click "Copy all content"
3. Create new Post and select the first empty paragraph
4. Paste the content using CMD/CTRL + V

Using WordPress 5.4.1 with Gutenberg plugin 8.1.0

[karmatosed]

Thanks for reporting this @phpbits. In testing, I found that another page worked for me, just not the demo content. Can you confirm that another page works for you, for example, mine had a button block in it.

If it is just the demo content, we should still resolve, but it might help narrow down the problem.

[ehti]

Same here, the demo page seems to be the exception - everything else works fine.

Haven't been able to figure out what exactly is happening with the Demo page.

[ballerburg9005]

I randomly experience this issue with latest Wordpress. Just doesn't paste from the clipboard (not even middle mouse paste on Linux) and no matter where I try it. It only accepts actual typing from the keyboard.

Turns out this time, it was related to brackets <> within the paste. If I copy & paste only partially with one bracket, it works.

[skorasaurus]

I've narrowed it down and was able to isolate this to the button block that is being used.

To reproduce:

1. create new post
2. take this code - https://gist.github.com/skorasaurus/56cce7c3e74a3dd6a1ce5c80cb0252ed - and paste in the code editor:
   That code/markup is from the single button that is in the demo post.
3. copy all content
4. paste

What happens: the button block is not added again, which is what you'd expect.
@phpbits: mind confirming this and updating the issue title?

[github-actions]

Help us move this issue forward. This issue is being marked stale since it has no activity after 15 days of requesting more information. Please add info requested so we can help move the issue forward. Note: The triage policy is to close stale issues that need more info and no response after 2 weeks.

[skorasaurus]

I can confirm that the issue still exists; the content in demo page was last updated 2020 - https://github.com/WordPress/gutenberg/blob/trunk/post-content.php

Next step would be either to update the content of that page to use current markup (e.g. button block); or investigate why old block markup isn't being copied; I noticed the duplicate feature was not available when I selected that button block in the demo page.