Lorem ipsum dolor sit amet, consectetur adipiscing elit.
``` Initially I assumed it might have been something in my code causing this but then I looked at one of the examples on the ProseMirror site and it seems to occur there as well. It’s not a major issue for me, and I only ever discovered it when I was viewing my editor in a mobile window and noticed some funny line breaks. In any case, I was wondering if there was a way to prevent this from happening. I’m also willing to accept that there may be some technical reason they should be added that I haven’t yet considered. --- This is not intentional behavior, and probably caused by the browser’s handling of clipboard data. Which browser is this happening in (I’m not seeing it in Firefox)? --- So I first noticed it in Chrome. I tried it in Firefox and Safari and at first I didn’t see it there as well when I went to inspect the element. However, I then tried viewing some HTML documents that I knew had non-breaking spaces and I also didn’t see them in Firefox when I went to inspect. But the non-breaking behavior was still present in those browsers (words were still sticking together in the places where the non-breaking spaces were). I’m probably missing something here, but I suspect that Firefox and Safari may not be showing the actual ` ` entities in their inspectors. When I copy the same HTML out of those browsers and into a text editor I see the ` ` entities again. --- So it looks like it is indeed caused by the browser’s handling of clipboard data. I was initially confused because I tried to use the `transformPastedHTML` method to see if I could clean up the HTML before it got parsed, but I couldn’t spot the non-breaking spaces in the raw HTML so I assumed they were being added afterward somehow. It turns out I was just failing to match on them correctly. I was able find and replace them with the following: ```auto transformPastedHTML: function(html) { return html.replaceAll(/\u00A0/g, " "); } ``` Anyways, sorry for the false alarm! --- You can reliably locate non-breaking spaces with `view.state.doc.textContent.replace(/\u00a0/g, "!!")`. The issue appears to be that Chrome and Safari mangle content they put on the clipboard by replacing some spaces in the actual copied content with non-breaking spaces. By the time ProseMirror sees the HTML, it can’t reliably see anymore whether a given non-breaking space is intentional or inserted by the browser. It seems CKEditor has a [hack](https://github.com/qihan/ckeditor/blob/8f3c81bd98b979ce36521a8eda42ca2d18588752/packages/ckeditor5-clipboard/src/utils/normalizeclipboarddata.js) to replace all spans with a single non-breaking space in them, and optionally an `Apple-converted-space` class (Safari seems to label these spaces, Chrome unfortunately doesn’t). [This patch](https://github.com/ProseMirror/prosemirror-view/commit/3aa9ae0c49ddfca12807ea61621b46bc280a0fb1) copies that approach. --- Yup, I realize now that my not being able to properly spot the non-breaking space was the issue. Also, thanks for creating this incredible library!