From 69589c19e7f822749f5a1664f63ba74b2772a2fc Mon Sep 17 00:00:00 2001
From: Luke Barnard <lukeb@openmarket.com>
Date: Tue, 27 Jun 2017 18:33:45 +0100
Subject: [PATCH 1/4] Work around draft-js-export-html#62 by post-processing
 <br>\n

Fixes https://github.com/vector-im/riot-web/issues/4446 by post-processing the output HTML from draft-js-export-html by replacing `<br>\n` with `<br>`. This works for content within or outside of `<pre>`. If we replace with `\n` instead, the newlines only apply in `<pre>` tags so we use `<br>`.
---
 src/components/views/rooms/MessageComposerInput.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/components/views/rooms/MessageComposerInput.js b/src/components/views/rooms/MessageComposerInput.js
index b05beb2571..cca0a9899c 100644
--- a/src/components/views/rooms/MessageComposerInput.js
+++ b/src/components/views/rooms/MessageComposerInput.js
@@ -509,7 +509,7 @@ export default class MessageComposerInput extends React.Component {
         if (this.state.isRichtextEnabled) {
             contentHTML = HtmlUtils.stripParagraphs(
                 RichText.contentStateToHTML(contentState),
-            );
+            ).replace(/\<br\>\n/g, '<br>');
         } else {
             const md = new Markdown(contentText);
             if (md.isPlainText()) {

From f73fa4b49b0eb6709d6784e1ea32eb406d42fb3f Mon Sep 17 00:00:00 2001
From: Luke Barnard <lukeb@openmarket.com>
Date: Wed, 28 Jun 2017 11:49:50 +0100
Subject: [PATCH 2/4] Move processing into renamed function
 processHtmlforSending

And explain why this fix is necessary
---
 src/HtmlUtils.js                                   | 8 +++++++-
 src/components/views/rooms/MessageComposerInput.js | 4 ++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/HtmlUtils.js b/src/HtmlUtils.js
index a32d05e4ff..cc302e24e5 100644
--- a/src/HtmlUtils.js
+++ b/src/HtmlUtils.js
@@ -84,7 +84,13 @@ export function charactersToImageNode(alt, useSvg, ...unicode) {
 }
 
 
-export function stripParagraphs(html: string): string {
+export function processHtmlForSending(html: string): string {
+    // Replace "<br>\n" with "<br>" because the \n is redundant and causes an
+    // extra newline per line within `<pre>` tags.
+    // This is a workaround for a bug in draft-js-export-html:
+    //   https://github.com/sstur/draft-js-export-html/issues/62
+    html = html.replace(/\<br\>\n/g, '<br>');
+
     const contentDiv = document.createElement('div');
     contentDiv.innerHTML = html;
 
diff --git a/src/components/views/rooms/MessageComposerInput.js b/src/components/views/rooms/MessageComposerInput.js
index cca0a9899c..aa6f3f2ac5 100644
--- a/src/components/views/rooms/MessageComposerInput.js
+++ b/src/components/views/rooms/MessageComposerInput.js
@@ -507,9 +507,9 @@ export default class MessageComposerInput extends React.Component {
         }
 
         if (this.state.isRichtextEnabled) {
-            contentHTML = HtmlUtils.stripParagraphs(
+            contentHTML = HtmlUtils.processHtmlForSending(
                 RichText.contentStateToHTML(contentState),
-            ).replace(/\<br\>\n/g, '<br>');
+            );
         } else {
             const md = new Markdown(contentText);
             if (md.isPlainText()) {

From eeb1c3386827f24ef2484eb665b05000f0957852 Mon Sep 17 00:00:00 2001
From: Luke Barnard <lukeb@openmarket.com>
Date: Wed, 28 Jun 2017 14:27:24 +0100
Subject: [PATCH 3/4] Do the less invasive fix of replacing `<br>\n` with `\n`
 but only within `<pre>`

---
 src/HtmlUtils.js | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/HtmlUtils.js b/src/HtmlUtils.js
index cc302e24e5..13b3f3094f 100644
--- a/src/HtmlUtils.js
+++ b/src/HtmlUtils.js
@@ -85,11 +85,6 @@ export function charactersToImageNode(alt, useSvg, ...unicode) {
 
 
 export function processHtmlForSending(html: string): string {
-    // Replace "<br>\n" with "<br>" because the \n is redundant and causes an
-    // extra newline per line within `<pre>` tags.
-    // This is a workaround for a bug in draft-js-export-html:
-    //   https://github.com/sstur/draft-js-export-html/issues/62
-    html = html.replace(/\<br\>\n/g, '<br>');
 
     const contentDiv = document.createElement('div');
     contentDiv.innerHTML = html;
@@ -103,6 +98,14 @@ export function processHtmlForSending(html: string): string {
         const element = contentDiv.children[i];
         if (element.tagName.toLowerCase() === 'p') {
             contentHTML += element.innerHTML + '<br />';
+        } else if (element.tagName.toLowerCase() === 'pre') {
+            // Replace "<br>\n" with "<br>" because the \n is redundant and causes an
+            // extra newline per line within `<pre>` tags.
+            // This is a workaround for a bug in draft-js-export-html:
+            //   https://github.com/sstur/draft-js-export-html/issues/62
+            contentHTML += '<pre>' +
+                element.innerHTML.replace(/<br>\n/g, '\n').trim() +
+                '</pre>';
         } else {
             const temp = document.createElement('div');
             temp.appendChild(element.cloneNode(true));

From 9b24f70d0052dd763e23848e7f3b307e1d24172c Mon Sep 17 00:00:00 2001
From: Luke Barnard <lukeb@openmarket.com>
Date: Wed, 28 Jun 2017 14:29:53 +0100
Subject: [PATCH 4/4] Update comment

---
 src/HtmlUtils.js | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/HtmlUtils.js b/src/HtmlUtils.js
index 13b3f3094f..ee679391cc 100644
--- a/src/HtmlUtils.js
+++ b/src/HtmlUtils.js
@@ -99,9 +99,8 @@ export function processHtmlForSending(html: string): string {
         if (element.tagName.toLowerCase() === 'p') {
             contentHTML += element.innerHTML + '<br />';
         } else if (element.tagName.toLowerCase() === 'pre') {
-            // Replace "<br>\n" with "<br>" because the \n is redundant and causes an
-            // extra newline per line within `<pre>` tags.
-            // This is a workaround for a bug in draft-js-export-html:
+            // Replace "<br>\n" with "\n" within `<pre>` tags because the <br> is
+            // redundant. This is a workaround for a bug in draft-js-export-html:
             //   https://github.com/sstur/draft-js-export-html/issues/62
             contentHTML += '<pre>' +
                 element.innerHTML.replace(/<br>\n/g, '\n').trim() +