Fix mailto handling when Brave is default

Auditors: @diracdeltas

Fix #4487

app/cmdLine.js

@@ -43,19 +43,25 @@ const focusOrOpenWindow = function (url) {
   return true
 }
 
+const isProtocolHandled = (protocol) => {
+  protocol = (protocol || '').split(':')[0]
+  return navigatableTypes.includes(protocol) ||
+      electron.session.defaultSession.protocol.isNavigatorProtocolHandled(protocol)
+}
+
 // Checks an array of arguments if it can find a url
 const getUrlFromCommandLine = (argv) => {
   if (argv) {
     if (argv.length === 2 && !argv[1].startsWith('-')) {
       const parsedUrl = urlParse(argv[1])
-      if (navigatableTypes.includes(parsedUrl.protocol)) {
+      if (isProtocolHandled(parsedUrl.protocol)) {
         return argv[1]
       }
     }
     const index = argv.indexOf('--')
     if (index !== -1 && index + 1 < argv.length && !argv[index + 1].startsWith('-')) {
       const parsedUrl = urlParse(argv[index + 1])
-      if (navigatableTypes.includes(parsedUrl.protocol)) {
+      if (isProtocolHandled(parsedUrl.protocol)) {
         return argv[index + 1]
       }
     }
@@ -68,7 +74,7 @@ if (!isDarwin) {
   const openUrl = getUrlFromCommandLine(process.argv)
   if (openUrl) {
     const parsedUrl = urlParse(openUrl)
-    if (navigatableTypes.includes(parsedUrl.protocol)) {
+    if (isProtocolHandled(parsedUrl.protocol)) {
       module.exports.newWindowURL = openUrl
     }
   }
@@ -101,7 +107,7 @@ app.on('will-finish-launching', () => {
   app.on('open-url', (event, path) => {
     event.preventDefault()
     const parsedUrl = urlParse(path)
-    if (navigatableTypes.includes(parsedUrl.protocol)) {
+    if (isProtocolHandled(parsedUrl.protocol)) {
       if (!focusOrOpenWindow(path)) {
         module.exports.newWindowURL = path
       }

js/lib/urlutil.js

@@ -108,7 +108,7 @@ const UrlUtil = {
     // for cases, pure string
     const case3Reg = /[\?\.\/\s:]/
     // for cases, data:uri, view-source:uri and about
-    const case4Reg = /^data|view-source|about|chrome-extension:.*/
+    const case4Reg = /^data|view-source|mailto|about|chrome-extension:.*/
 
     let str = input.trim()
     let scheme = this.getScheme(str)

test/unit/lib/urlutilTest.js

@@ -75,6 +75,9 @@ describe('urlutil', function () {
     it('returns false when input is chrome-extension', function () {
       assert.equal(UrlUtil.isNotURL('chrome-extension://fmfcbgogabcbclcofgocippekhfcmgfj/cast_sender.js'), false)
     })
+    it('returns false when input is mailto', function () {
+      assert.equal(UrlUtil.isNotURL('mailto:brian@brave.com'), false)
+    })
     describe('search query', function () {
       it('returns true when input starts with ?', function () {
         assert.equal(UrlUtil.isNotURL('?brave'), true)