From bd99b258481d5519e7ee84079e99f758984584ee Mon Sep 17 00:00:00 2001
From: Laurent Cozic <laurent@cozic.net>
Date: Fri, 10 Apr 2020 17:12:41 +0000
Subject: [PATCH] Desktop: WYSIWYG: Preserve HTML code in Markdown when editing
 from wysiwyg editor

---
 CliClient/package-lock.json                   | 49 ++++++++++-----
 CliClient/package.json                        |  2 +-
 CliClient/tests/html_to_md/html_in_md.html    |  6 ++
 CliClient/tests/html_to_md/html_in_md.md      |  9 +++
 CliClient/tests/md_to_html/html_in_md.html    |  4 ++
 CliClient/tests/md_to_html/html_in_md.md      |  4 ++
 CliClient/tests/md_to_html/sanitize.html      |  4 +-
 CliClient/tests/md_to_html/sanitize_10.html   |  2 +-
 CliClient/tests/md_to_html/sanitize_2.html    |  2 +-
 CliClient/tests/md_to_html/sanitize_3.html    |  2 +-
 CliClient/tests/md_to_html/sanitize_4.html    |  2 +-
 CliClient/tests/md_to_html/sanitize_5.html    |  2 +-
 CliClient/tests/md_to_html/sanitize_6.html    |  2 +-
 CliClient/tests/md_to_html/sanitize_9.html    |  2 +-
 ElectronClient/gui/NoteText2.tsx              | 11 ++++
 ElectronClient/gui/editors/TinyMCE.tsx        |  2 +-
 ElectronClient/package-lock.json              | 60 +++++++++++++------
 ElectronClient/package.json                   |  2 +-
 .../MdToHtml/rules/sanitize_html.ts           |  2 +-
 .../lib/joplin-renderer/htmlUtils.js          | 17 +++++-
 .../lib/joplin-renderer/tests/MdToHtmlTest.js | 24 --------
 21 files changed, 139 insertions(+), 71 deletions(-)
 create mode 100644 CliClient/tests/html_to_md/html_in_md.html
 create mode 100644 CliClient/tests/html_to_md/html_in_md.md
 create mode 100644 CliClient/tests/md_to_html/html_in_md.html
 create mode 100644 CliClient/tests/md_to_html/html_in_md.md
 delete mode 100644 ReactNativeClient/lib/joplin-renderer/tests/MdToHtmlTest.js

diff --git a/CliClient/package-lock.json b/CliClient/package-lock.json
index 704f86fb2..c02fc2576 100644
--- a/CliClient/package-lock.json
+++ b/CliClient/package-lock.json
@@ -2111,7 +2111,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -2132,12 +2133,14 @@
         "balanced-match": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -2152,17 +2155,20 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -2279,7 +2285,8 @@
         "inherits": {
           "version": "2.0.4",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.5",
@@ -2291,6 +2298,7 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -2305,6 +2313,7 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -2312,12 +2321,14 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "minipass": {
           "version": "2.9.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.2",
             "yallist": "^3.0.0"
@@ -2336,6 +2347,7 @@
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -2425,7 +2437,8 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -2437,6 +2450,7 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -2522,7 +2536,8 @@
         "safe-buffer": {
           "version": "5.1.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -2558,6 +2573,7 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -2577,6 +2593,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -2620,12 +2637,14 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },
@@ -3730,9 +3749,9 @@
       "dev": true
     },
     "joplin-turndown": {
-      "version": "4.0.24",
-      "resolved": "https://registry.npmjs.org/joplin-turndown/-/joplin-turndown-4.0.24.tgz",
-      "integrity": "sha512-mKd2rAFzJKnhTVjEpHomG+T01//uz5rXVSAOYRh3/JKXpY7QUhVp8jCmFfO+kaadrLABTz04mvTmyyoOadxdTA==",
+      "version": "4.0.27",
+      "resolved": "https://registry.npmjs.org/joplin-turndown/-/joplin-turndown-4.0.27.tgz",
+      "integrity": "sha512-qwJEzpbsyXnfjYgCVXWbuf3BdbDAaP7edm5ubeVAaQ3RnaiSEB2xZLg3lubmuFOIxXnkMDMkGJC4G+qAbCW95w==",
       "requires": {
         "css": "^2.2.4",
         "html-entities": "^1.2.1",
@@ -6590,7 +6609,7 @@
       "requires": {
         "chalk": "^2.1.0",
         "emphasize": "^1.5.0",
-        "node-emoji": "git+https://github.com/laurent22/node-emoji.git#9fa01eac463e94dde1316ef8c53089eeef4973b5",
+        "node-emoji": "git+https://github.com/laurent22/node-emoji.git",
         "slice-ansi": "^1.0.0",
         "string-width": "^2.1.1",
         "terminal-kit": "^1.13.11",
diff --git a/CliClient/package.json b/CliClient/package.json
index 6d0e666b1..e4973af59 100644
--- a/CliClient/package.json
+++ b/CliClient/package.json
@@ -55,7 +55,7 @@
     "htmlparser2": "^4.1.0",
     "image-data-uri": "^2.0.0",
     "image-type": "^3.0.0",
-    "joplin-turndown": "^4.0.24",
+    "joplin-turndown": "^4.0.27",
     "joplin-turndown-plugin-gfm": "^1.0.12",
     "json-stringify-safe": "^5.0.1",
     "jssha": "^2.3.0",
diff --git a/CliClient/tests/html_to_md/html_in_md.html b/CliClient/tests/html_to_md/html_in_md.html
new file mode 100644
index 000000000..4b37317cd
--- /dev/null
+++ b/CliClient/tests/html_to_md/html_in_md.html
@@ -0,0 +1,6 @@
+<p>Line 1</p>
+<div class="jop-noMdConv">Line 2</div>
+<div class="jop-noMdConv"><span class="jop-noMdConv">Line</span> 4</div>
+<div><span>Line</span> 5</div>
+<p>Line 6</p>
+<div class="jop-noMdConv">Markdown <strong>inside</strong></div>
\ No newline at end of file
diff --git a/CliClient/tests/html_to_md/html_in_md.md b/CliClient/tests/html_to_md/html_in_md.md
new file mode 100644
index 000000000..7c92246ea
--- /dev/null
+++ b/CliClient/tests/html_to_md/html_in_md.md
@@ -0,0 +1,9 @@
+Line 1
+
+<div>Line 2</div><div><span>Line</span> 4</div>
+
+Line 5
+
+Line 6
+
+<div>Markdown **inside**</div>
\ No newline at end of file
diff --git a/CliClient/tests/md_to_html/html_in_md.html b/CliClient/tests/md_to_html/html_in_md.html
new file mode 100644
index 000000000..2f9323ff0
--- /dev/null
+++ b/CliClient/tests/md_to_html/html_in_md.html
@@ -0,0 +1,4 @@
+<p>Line 1</p>
+<div class="jop-noMdConv">Line 2</div>
+<div class="jop-noMdConv"><span class="jop-noMdConv">Line</span> 4</div>
+Line 5
\ No newline at end of file
diff --git a/CliClient/tests/md_to_html/html_in_md.md b/CliClient/tests/md_to_html/html_in_md.md
new file mode 100644
index 000000000..3aad8dd46
--- /dev/null
+++ b/CliClient/tests/md_to_html/html_in_md.md
@@ -0,0 +1,4 @@
+Line 1
+<div>Line 2</div>
+<div><span>Line</span> 4</div>
+Line 5
\ No newline at end of file
diff --git a/CliClient/tests/md_to_html/sanitize.html b/CliClient/tests/md_to_html/sanitize.html
index 7f871c790..0b7bbba7b 100644
--- a/CliClient/tests/md_to_html/sanitize.html
+++ b/CliClient/tests/md_to_html/sanitize.html
@@ -1,2 +1,2 @@
-<img src=""/>
-<img src=""/>
\ No newline at end of file
+<img src="" class="jop-noMdConv"/>
+<img src="" class="jop-noMdConv"/>
\ No newline at end of file
diff --git a/CliClient/tests/md_to_html/sanitize_10.html b/CliClient/tests/md_to_html/sanitize_10.html
index d75c322f2..f99f6f8d0 100644
--- a/CliClient/tests/md_to_html/sanitize_10.html
+++ b/CliClient/tests/md_to_html/sanitize_10.html
@@ -1,4 +1,4 @@
-<style>
+<style class="jop-noMdConv">
 .md-checkbox input[type="checkbox"]:not(:checked),
 .md-checkbox input[type="checkbox"]:not(:checked)+label {
     display:none;
diff --git a/CliClient/tests/md_to_html/sanitize_2.html b/CliClient/tests/md_to_html/sanitize_2.html
index e095d7d48..f6f0f079d 100644
--- a/CliClient/tests/md_to_html/sanitize_2.html
+++ b/CliClient/tests/md_to_html/sanitize_2.html
@@ -1 +1 @@
-<p><a href="#">Testing <strong>inline</strong> text</a></p>
+<p><a href="#" class="jop-noMdConv">Testing <strong>inline</strong> text</a></p>
diff --git a/CliClient/tests/md_to_html/sanitize_3.html b/CliClient/tests/md_to_html/sanitize_3.html
index fd5681576..48b44344c 100644
--- a/CliClient/tests/md_to_html/sanitize_3.html
+++ b/CliClient/tests/md_to_html/sanitize_3.html
@@ -1 +1 @@
-<p>Should be <span style="color: red;">red</span>.</p>
+<p>Should be <span style="color: red;" class="jop-noMdConv">red</span>.</p>
diff --git a/CliClient/tests/md_to_html/sanitize_4.html b/CliClient/tests/md_to_html/sanitize_4.html
index fbafec90e..91eb8a9b1 100644
--- a/CliClient/tests/md_to_html/sanitize_4.html
+++ b/CliClient/tests/md_to_html/sanitize_4.html
@@ -1,4 +1,4 @@
-<div class="different">
+<div class="different jop-noMdConv">
 <h5 id="h5">H5</h5>
 <h6 id="h6">H6</h6>
 </div>
\ No newline at end of file
diff --git a/CliClient/tests/md_to_html/sanitize_5.html b/CliClient/tests/md_to_html/sanitize_5.html
index 819bccc5e..7970550fd 100644
--- a/CliClient/tests/md_to_html/sanitize_5.html
+++ b/CliClient/tests/md_to_html/sanitize_5.html
@@ -1,4 +1,4 @@
-<style>
+<style class="jop-noMdConv">
   .different h5 { color: lightgreen; }
   h5 { color: orange; }
   h6 { color: orange; }
diff --git a/CliClient/tests/md_to_html/sanitize_6.html b/CliClient/tests/md_to_html/sanitize_6.html
index e627988b4..b9d2916c4 100644
--- a/CliClient/tests/md_to_html/sanitize_6.html
+++ b/CliClient/tests/md_to_html/sanitize_6.html
@@ -1 +1 @@
-<p><mark>bla</mark></p>
+<p><mark class="jop-noMdConv">bla</mark></p>
diff --git a/CliClient/tests/md_to_html/sanitize_9.html b/CliClient/tests/md_to_html/sanitize_9.html
index 59fd9881e..0ca384655 100644
--- a/CliClient/tests/md_to_html/sanitize_9.html
+++ b/CliClient/tests/md_to_html/sanitize_9.html
@@ -1 +1 @@
-<div>M&amp;Ms</div>
\ No newline at end of file
+<div class="jop-noMdConv">M&amp;Ms</div>
\ No newline at end of file
diff --git a/ElectronClient/gui/NoteText2.tsx b/ElectronClient/gui/NoteText2.tsx
index fee2cffb0..2808d3d6d 100644
--- a/ElectronClient/gui/NoteText2.tsx
+++ b/ElectronClient/gui/NoteText2.tsx
@@ -375,6 +375,7 @@ function NoteText2(props:NoteTextProps) {
 	const titleInputRef = useRef<any>();
 	const formNoteRef = useRef<FormNote>();
 	formNoteRef.current = { ...formNote };
+	const isMountedRef = useRef(true);
 
 	useWindowCommand(props.windowCommand, props.dispatch, formNote, titleInputRef, editorRef);
 
@@ -471,6 +472,7 @@ function NoteText2(props:NoteTextProps) {
 		// formNote in the dependency array or that effect will run every time the note changes. We only
 		// want to run it once on unmount. So because of that we need to use that formNoteRef.
 		return () => {
+			isMountedRef.current = false;
 			saveNoteIfWillChange(formNoteRef.current, editorRef, props.dispatch);
 		};
 	}, []);
@@ -556,6 +558,15 @@ function NoteText2(props:NoteTextProps) {
 	}, [props.noteId, props.isProvisional, formNote, waitingToSaveNote]);
 
 	const onFieldChange = useCallback((field:string, value:any, changeId: number = 0) => {
+		if (!isMountedRef.current) {
+			// When the component is unmounted, various actions can happen which can
+			// trigger onChange events, for example the textarea might be cleared.
+			// We need to ignore these events, otherwise the note is going to be saved
+			// with an invalid body.
+			reg.logger().debug('Skipping change event because the component is unmounted');
+			return;
+		}
+
 		handleProvisionalFlag();
 
 		const change = field === 'body' ? {
diff --git a/ElectronClient/gui/editors/TinyMCE.tsx b/ElectronClient/gui/editors/TinyMCE.tsx
index 2fcf58592..2f71a8ee4 100644
--- a/ElectronClient/gui/editors/TinyMCE.tsx
+++ b/ElectronClient/gui/editors/TinyMCE.tsx
@@ -164,7 +164,7 @@ const TinyMCE = (props:TinyMCEProps, ref:any) => {
 		if (dispatchDidUpdateIID_) clearTimeout(dispatchDidUpdateIID_);
 		dispatchDidUpdateIID_ = setTimeout(() => {
 			dispatchDidUpdateIID_ = null;
-			editor.getDoc().dispatchEvent(new Event('joplin-noteDidUpdate'));
+			if (editor && editor.getDoc()) editor.getDoc().dispatchEvent(new Event('joplin-noteDidUpdate'));
 		}, 10);
 	};
 
diff --git a/ElectronClient/package-lock.json b/ElectronClient/package-lock.json
index 9e453afbd..35d829051 100644
--- a/ElectronClient/package-lock.json
+++ b/ElectronClient/package-lock.json
@@ -1309,7 +1309,8 @@
               "version": "5.1.2",
               "resolved": false,
               "integrity": "sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g==",
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "safer-buffer": {
               "version": "2.1.2",
@@ -1429,7 +1430,8 @@
               "version": "3.0.3",
               "resolved": false,
               "integrity": "sha512-S+Zk8DEWE6oKpV+vI3qWkaK+jSbIK86pCwe2IF/xwIpQ8jEuxpw9NyaGjmp9+BoJv5FV2piqCDcoCtStppiq2A==",
-              "dev": true
+              "dev": true,
+              "optional": true
             }
           }
         },
@@ -1447,13 +1449,15 @@
           "version": "1.0.0",
           "resolved": "https://registry.npmjs.org/is-extglob/-/is-extglob-1.0.0.tgz",
           "integrity": "sha1-rEaBd8SUNAWgkvyPKXYMb/xiBsA=",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "is-glob": {
           "version": "2.0.1",
           "resolved": "https://registry.npmjs.org/is-glob/-/is-glob-2.0.1.tgz",
           "integrity": "sha1-0Jb5JqPe1WAPP9/ZEZjLCIjC2GM=",
           "dev": true,
+          "optional": true,
           "requires": {
             "is-extglob": "^1.0.0"
           }
@@ -1941,7 +1945,8 @@
       "version": "3.0.1",
       "resolved": "https://registry.npmjs.org/boolean/-/boolean-3.0.1.tgz",
       "integrity": "sha512-HRZPIjPcbwAVQvOTxR4YE3o8Xs98NqbbL1iEZDCz7CL8ql0Lt5iOyJFxfnAB0oFs8Oh02F/lLlg30Mexv46LjA==",
-      "dev": true
+      "dev": true,
+      "optional": true
     },
     "boxen": {
       "version": "4.2.0",
@@ -4933,13 +4938,15 @@
           "version": "1.0.0",
           "resolved": "https://registry.npmjs.org/is-extglob/-/is-extglob-1.0.0.tgz",
           "integrity": "sha1-rEaBd8SUNAWgkvyPKXYMb/xiBsA=",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "is-glob": {
           "version": "2.0.1",
           "resolved": "https://registry.npmjs.org/is-glob/-/is-glob-2.0.1.tgz",
           "integrity": "sha1-0Jb5JqPe1WAPP9/ZEZjLCIjC2GM=",
           "dev": true,
+          "optional": true,
           "requires": {
             "is-extglob": "^1.0.0"
           }
@@ -5107,7 +5114,8 @@
               "version": "2.1.1",
               "resolved": false,
               "integrity": "sha1-w7M6te42DYbg5ijwRorn7yfWVN8=",
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "aproba": {
               "version": "1.2.0",
@@ -5156,7 +5164,8 @@
               "version": "1.1.0",
               "resolved": false,
               "integrity": "sha1-DQcLTQQ6W+ozovGkDi7bPZpMz3c=",
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "concat-map": {
               "version": "0.0.1",
@@ -5169,7 +5178,8 @@
               "version": "1.1.0",
               "resolved": false,
               "integrity": "sha1-PXz0Rk22RG6mRL9LOVB/mFEAjo4=",
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "core-util-is": {
               "version": "1.0.2",
@@ -5300,7 +5310,8 @@
               "version": "2.0.4",
               "resolved": false,
               "integrity": "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ==",
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "ini": {
               "version": "1.3.5",
@@ -5314,6 +5325,7 @@
               "resolved": false,
               "integrity": "sha1-754xOG8DGn8NZDr4L95QxFfvAMs=",
               "dev": true,
+              "optional": true,
               "requires": {
                 "number-is-nan": "^1.0.0"
               }
@@ -5330,6 +5342,7 @@
               "resolved": false,
               "integrity": "sha512-yJHVQEhyqPLUTgt9B83PXu6W3rx4MvvHvSUvToogpwoGDOUQ+yDrR0HRot+yOCdCO7u4hX3pWft6kWBBcqh0UA==",
               "dev": true,
+              "optional": true,
               "requires": {
                 "brace-expansion": "^1.1.7"
               }
@@ -5338,13 +5351,15 @@
               "version": "0.0.8",
               "resolved": false,
               "integrity": "sha1-hX/Kv8M5fSYluCKCYuhqp6ARsF0=",
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "minipass": {
               "version": "2.9.0",
               "resolved": false,
               "integrity": "sha512-wxfUjg9WebH+CUDX/CdbRlh5SmfZiy/hpkxaRI16Y9W56Pa75sWgd/rvFilSgrauD9NyFymP/+JFV3KwzIsJeg==",
               "dev": true,
+              "optional": true,
               "requires": {
                 "safe-buffer": "^5.1.2",
                 "yallist": "^3.0.0"
@@ -5365,6 +5380,7 @@
               "resolved": false,
               "integrity": "sha1-MAV0OOrGz3+MR2fzhkjWaX11yQM=",
               "dev": true,
+              "optional": true,
               "requires": {
                 "minimist": "0.0.8"
               }
@@ -5463,7 +5479,8 @@
               "version": "1.0.1",
               "resolved": false,
               "integrity": "sha1-CXtgK1NCKlIsGvuHkDGDNpQaAR0=",
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "object-assign": {
               "version": "4.1.1",
@@ -5477,6 +5494,7 @@
               "resolved": false,
               "integrity": "sha1-WDsap3WWHUsROsF9nFC6753Xa9E=",
               "dev": true,
+              "optional": true,
               "requires": {
                 "wrappy": "1"
               }
@@ -5572,7 +5590,8 @@
               "version": "5.1.2",
               "resolved": false,
               "integrity": "sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g==",
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "safer-buffer": {
               "version": "2.1.2",
@@ -5614,6 +5633,7 @@
               "resolved": false,
               "integrity": "sha1-EYvfW4zcUaKn5w0hHgfisLmxB9M=",
               "dev": true,
+              "optional": true,
               "requires": {
                 "code-point-at": "^1.0.0",
                 "is-fullwidth-code-point": "^1.0.0",
@@ -5635,6 +5655,7 @@
               "resolved": false,
               "integrity": "sha1-ajhfuIU9lS1f8F0Oiq+UJ43GPc8=",
               "dev": true,
+              "optional": true,
               "requires": {
                 "ansi-regex": "^2.0.0"
               }
@@ -5683,13 +5704,15 @@
               "version": "1.0.2",
               "resolved": false,
               "integrity": "sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8=",
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "yallist": {
               "version": "3.1.1",
               "resolved": false,
               "integrity": "sha512-a4UGQaWPH59mOXUYnAG2ewncQS4i4F43Tv3JoAM+s2VDAmS9NsK8GpDMLrCHPksFT7h3K6TOoUNn2pb7RoXx4g==",
-              "dev": true
+              "dev": true,
+              "optional": true
             }
           }
         },
@@ -6711,9 +6734,9 @@
       "integrity": "sha1-R+Y/evVa+m+S4VAOaQ64uFKcCZo="
     },
     "joplin-turndown": {
-      "version": "4.0.24",
-      "resolved": "https://registry.npmjs.org/joplin-turndown/-/joplin-turndown-4.0.24.tgz",
-      "integrity": "sha512-mKd2rAFzJKnhTVjEpHomG+T01//uz5rXVSAOYRh3/JKXpY7QUhVp8jCmFfO+kaadrLABTz04mvTmyyoOadxdTA==",
+      "version": "4.0.27",
+      "resolved": "https://registry.npmjs.org/joplin-turndown/-/joplin-turndown-4.0.27.tgz",
+      "integrity": "sha512-qwJEzpbsyXnfjYgCVXWbuf3BdbDAaP7edm5ubeVAaQ3RnaiSEB2xZLg3lubmuFOIxXnkMDMkGJC4G+qAbCW95w==",
       "requires": {
         "css": "^2.2.4",
         "html-entities": "^1.2.1",
@@ -8621,7 +8644,8 @@
           "version": "1.0.0",
           "resolved": "https://registry.npmjs.org/is-extglob/-/is-extglob-1.0.0.tgz",
           "integrity": "sha1-rEaBd8SUNAWgkvyPKXYMb/xiBsA=",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "is-glob": {
           "version": "2.0.1",
diff --git a/ElectronClient/package.json b/ElectronClient/package.json
index 1f338c860..3ce74f33c 100644
--- a/ElectronClient/package.json
+++ b/ElectronClient/package.json
@@ -110,7 +110,7 @@
     "html-minifier": "^4.0.0",
     "htmlparser2": "^4.1.0",
     "image-type": "^3.0.0",
-    "joplin-turndown": "^4.0.24",
+    "joplin-turndown": "^4.0.27",
     "joplin-turndown-plugin-gfm": "^1.0.12",
     "json-stringify-safe": "^5.0.1",
     "jssha": "^2.3.1",
diff --git a/ReactNativeClient/lib/joplin-renderer/MdToHtml/rules/sanitize_html.ts b/ReactNativeClient/lib/joplin-renderer/MdToHtml/rules/sanitize_html.ts
index d221fa236..cb91b9adc 100644
--- a/ReactNativeClient/lib/joplin-renderer/MdToHtml/rules/sanitize_html.ts
+++ b/ReactNativeClient/lib/joplin-renderer/MdToHtml/rules/sanitize_html.ts
@@ -32,7 +32,7 @@ function installRule(markdownIt:any, mdOptions:any, ruleOptions:any, context:any
 				// So the sanitizeHtml function must handle this kind of non-valid HTML.
 
 				if (!sanitizedContent) {
-					sanitizedContent = htmlUtils.sanitizeHtml(token.content);
+					sanitizedContent = htmlUtils.sanitizeHtml(token.content, { addNoMdConvClass: true });
 				}
 
 				token.content = sanitizedContent;
diff --git a/ReactNativeClient/lib/joplin-renderer/htmlUtils.js b/ReactNativeClient/lib/joplin-renderer/htmlUtils.js
index e4d446ade..7b6eb9862 100644
--- a/ReactNativeClient/lib/joplin-renderer/htmlUtils.js
+++ b/ReactNativeClient/lib/joplin-renderer/htmlUtils.js
@@ -70,7 +70,13 @@ class HtmlUtils {
 		return selfClosingElements.includes(tagName.toLowerCase());
 	}
 
-	sanitizeHtml(html) {
+	sanitizeHtml(html, options = null) {
+		options = Object.assign({}, {
+			// If true, adds a "jop-noMdConv" class to all the tags.
+			// It can be used afterwards to restore HTML tags in Markdown.
+			addNoMdConvClass: false,
+		}, options);
+
 		const htmlparser2 = require('htmlparser2');
 
 		const output = [];
@@ -95,6 +101,15 @@ class HtmlUtils {
 				for (const eventName of JS_EVENT_NAMES) {
 					delete attrs[eventName];
 				}
+
+				if (options.addNoMdConvClass) {
+					let classAttr = attrs['class'] || '';
+					if (!classAttr.includes('jop-noMdConv')) {
+						classAttr += ' jop-noMdConv';
+						attrs['class'] = classAttr.trim();
+					}
+				}
+
 				let attrHtml = this.attributesHtml(attrs);
 				if (attrHtml) attrHtml = ` ${attrHtml}`;
 				const closingSign = this.isSelfClosingTag(name) ? '/>' : '>';
diff --git a/ReactNativeClient/lib/joplin-renderer/tests/MdToHtmlTest.js b/ReactNativeClient/lib/joplin-renderer/tests/MdToHtmlTest.js
deleted file mode 100644
index a1457c35d..000000000
--- a/ReactNativeClient/lib/joplin-renderer/tests/MdToHtmlTest.js
+++ /dev/null
@@ -1,24 +0,0 @@
-const { asyncTest } = require('./test-utils');
-const MdToHtml = require('../MdToHtml');
-
-describe('MdToHtml', function() {
-
-	beforeEach(async (done) => {
-		done();
-	});
-
-	it('should convert Markdown to HTML', asyncTest(async () => {
-		const mdToHtml = new MdToHtml({
-			ResourceModel: null,
-		});
-
-		const md = 'Testing: **Testing**';
-
-		const html = mdToHtml.render(md);
-
-		console.info(html);
-
-		// ![test.jpg](:/b08c25f72bea437ebef5f6470944c3b9)
-	}));
-
-});