fix-shortcode-pasting-plain-text-1.diff

diff --git a/blocks/api/raw-handling/index.js b/blocks/api/raw-handling/index.js
index c5a95ecc..66fb4e39 100644
--- a/blocks/api/raw-handling/index.js
+++ b/blocks/api/raw-handling/index.js
@@ -22,7 +22,7 @@ import imageCorrector from './image-corrector';
 import blockquoteNormaliser from './blockquote-normaliser';
 import tableNormaliser from './table-normaliser';
 import inlineContentConverter from './inline-content-converter';
-import { deepFilterHTML, isInvalidInline, isNotWhitelisted, isPlain, isInline } from './utils';
+import { deepFilterHTML, isInvalidInline, isNotWhitelisted, isPlain, isInline, stripOuterP } from './utils';
 import shortcodeConverter from './shortcode-converter';
 
 /**
@@ -48,13 +48,20 @@ export default function rawHandler( { HTML, plainText = '', mode = 'AUTO' } ) {
 	// If there is a plain text version, the HTML version has no formatting,
 	// and there is at least a double line break,
 	// parse any Markdown inside the plain text.
-	if ( plainText && isPlain( HTML ) && plainText.indexOf( '\n\n' ) !== -1 ) {
+	if ( plainText && isPlain( HTML ) ) {
 		const converter = new showdown.Converter();
 
 		converter.setOption( 'noHeaderId', true );
 		converter.setOption( 'tables', true );
 
 		HTML = converter.makeHtml( plainText );
+
+		// If there are no paragraphs in the original plain text, the paste
+		// should be treated as inline. However, Markdown conversion returns
+		// P-wrapped paragraphs, so we strip that outer P node.
+		if ( plainText.indexOf( '\n\n' ) === -1 ) {
+			HTML = stripOuterP( HTML );
+		}
 	}
 
 	// Return filtered HTML if it's inline paste or all content is inline.
diff --git a/blocks/api/raw-handling/utils.js b/blocks/api/raw-handling/utils.js
index 1d17199c..9a147124 100644
--- a/blocks/api/raw-handling/utils.js
+++ b/blocks/api/raw-handling/utils.js
@@ -151,6 +151,26 @@ export function isPlain( HTML ) {
 	return doc.body.childNodes.length === 1 && doc.body.firstChild.nodeType === TEXT_NODE;
 }
 
+/**
+ * Given a string of HTML representing a P node with contents,
+ *
+ *   '<p>Hello, <em>you</em>!</p>'
+ *
+ * returns a string representing the contents of the P node:
+ *
+ *   'Hello, <em>you</em>!'
+ *
+ * @param  {String}         HTML        The HTML from which to strip the node.
+ * @return {String}         The stripped out HTML, or the original HTML as a fallback.
+ */
+export function stripOuterP( HTML ) {
+	const inputEl = document.createElement( 'div' );
+	inputEl.innerHTML = HTML;
+	return inputEl.children.length === 1 ?
+		inputEl.children[ 0 ].innerHTML :
+		HTML;
+}
+
 /**
  * Given node filters, deeply filters and mutates a NodeList.
  *
diff --git a/blocks/editable/index.js b/blocks/editable/index.js
index a75e28a5..201005a6 100644
--- a/blocks/editable/index.js
+++ b/blocks/editable/index.js
@@ -259,6 +259,7 @@ export default class Editable extends Component {
 
 	onPastePreProcess( event ) {
 		const HTML = this.isPlainTextPaste ? this.pastedPlainText : event.content;
+		//const HTML = event.content;
 		// Allows us to ask for this information when we get a report.
 		window.console.log( 'Received HTML:\n\n', this.pastedContent || HTML );
 		window.console.log( 'Received plain text:\n\n', this.pastedPlainText );