From dd14385cb439fad5f4a8aaa596a91037764a751d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20H=C3=A4usler?= <hfelix@protonmail.ch>
Date: Sun, 20 Feb 2022 13:52:37 +0100
Subject: [PATCH] fix clickable HTML links on Windows (#3015) (#3033)

---
 src/main/menu/actions/file.js      | 14 ++++++++++----
 src/muya/lib/utils/markdownFile.js | 24 ++++++++++++++++++++++++
 src/muya/lib/utils/url.js          | 18 ++++++++++++++++--
 3 files changed, 50 insertions(+), 6 deletions(-)
 create mode 100755 src/muya/lib/utils/markdownFile.js

diff --git a/src/main/menu/actions/file.js b/src/main/menu/actions/file.js
index ff44b711..4197d811 100644
--- a/src/main/menu/actions/file.js
+++ b/src/main/menu/actions/file.js
@@ -415,15 +415,20 @@ ipcMain.on('mt::format-link-click', (e, { data, dirname }) => {
     return
   }
 
-  const href = data.href || data.text
-  if (URL_REG.test(href)) {
-    shell.openExternal(href)
+  const urlCandidate = data.href || data.text
+  if (URL_REG.test(urlCandidate)) {
+    shell.openExternal(urlCandidate)
     return
-  } else if (/^[a-z0-9]+:\/\//i.test(href)) {
+  } else if (/^[a-z0-9]+:\/\//i.test(urlCandidate)) {
     // Prevent other URLs.
     return
   }
 
+  const href = data.href
+  if (!href) {
+    return
+  }
+
   let pathname = null
   if (path.isAbsolute(href)) {
     pathname = href
@@ -432,6 +437,7 @@ ipcMain.on('mt::format-link-click', (e, { data, dirname }) => {
   }
 
   if (pathname) {
+    pathname = path.normalize(pathname)
     if (isMarkdownFile(pathname)) {
       const win = BrowserWindow.fromWebContents(e.sender)
       openFileOrFolder(win, pathname)
diff --git a/src/muya/lib/utils/markdownFile.js b/src/muya/lib/utils/markdownFile.js
new file mode 100755
index 00000000..627f6af4
--- /dev/null
+++ b/src/muya/lib/utils/markdownFile.js
@@ -0,0 +1,24 @@
+// __MARKTEXT_ONLY__
+
+const MARKDOWN_EXTENSIONS = Object.freeze([
+  'markdown',
+  'mdown',
+  'mkdn',
+  'md',
+  'mkd',
+  'mdwn',
+  'mdtxt',
+  'mdtext',
+  'text',
+  'txt'
+])
+
+/**
+ * Returns true if the filename matches one of the markdown extensions allowed in MarkText.
+ *
+ * @param {string} filename Path or filename
+ */
+export const hasMarkdownExtension = filename => {
+  if (!filename || typeof filename !== 'string') return false
+  return MARKDOWN_EXTENSIONS.some(ext => filename.toLowerCase().endsWith(`.${ext}`))
+}
diff --git a/src/muya/lib/utils/url.js b/src/muya/lib/utils/url.js
index f6515841..885a4db8 100644
--- a/src/muya/lib/utils/url.js
+++ b/src/muya/lib/utils/url.js
@@ -1,8 +1,22 @@
 import { isValidAttribute } from '../utils/dompurify'
+import { isWin } from '../config' // __MARKTEXT_PATCH__
+import { hasMarkdownExtension } from './markdownFile' // __MARKTEXT_PATCH__
 
 export const sanitizeHyperlink = rawLink => {
-  if (rawLink && typeof rawLink === 'string' && isValidAttribute('a', 'href', rawLink)) {
-    return rawLink
+  if (rawLink && typeof rawLink === 'string') {
+    if (isValidAttribute('a', 'href', rawLink)) {
+      return rawLink
+    }
+
+    // __MARKTEXT_PATCH__
+    if (isWin && /^[a-zA-Z]:[/\\].+/.test(rawLink) && hasMarkdownExtension(rawLink)) {
+      // Create and try UNC path on Windows because "C:\file.md" isn't allowed.
+      const uncPath = `\\\\?\\${rawLink}`
+      if (isValidAttribute('a', 'href', uncPath)) {
+        return uncPath
+      }
+    }
+    // END __MARKTEXT_PATCH__
   }
   return ''
 }