From 3864761029551a56b845b146b549252b78a4a28d Mon Sep 17 00:00:00 2001
From: Vladimir Dementyev <dementiev.vm@gmail.com>
Date: Wed, 22 Jul 2020 17:31:56 +0300
Subject: [PATCH 1/3] fix: fallback page should use path not file location

When resolving fallback page for the path (`fallbackLanguages` option), we should consider the original path, not the file location (which could be different when aliases are used).
---
 src/core/fetch/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/core/fetch/index.js b/src/core/fetch/index.js
index 9d2769b84..923dc3e90 100644
--- a/src/core/fetch/index.js
+++ b/src/core/fetch/index.js
@@ -123,7 +123,7 @@ export function fetchMixin(proto) {
           this._loadSideAndNav(path, qs, loadSidebar, cb)
         ),
       _ => {
-        this._fetchFallbackPage(file, qs, cb) || this._fetch404(file, qs, cb);
+        this._fetchFallbackPage(path, qs, cb) || this._fetch404(file, qs, cb);
       }
     );
 

From f87d9a56042e3c36c60ffe30f1c0d75400ccd31d Mon Sep 17 00:00:00 2001
From: Vladimir Dementyev <dementiev.vm@gmail.com>
Date: Wed, 22 Jul 2020 17:38:23 +0300
Subject: [PATCH 2/3] fix: use router.getFile to resolve fallback url

---
 src/core/fetch/index.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/core/fetch/index.js b/src/core/fetch/index.js
index 923dc3e90..6bf592c96 100644
--- a/src/core/fetch/index.js
+++ b/src/core/fetch/index.js
@@ -209,7 +209,9 @@ export function fetchMixin(proto) {
       return false;
     }
 
-    const newPath = path.replace(new RegExp(`^/${local}`), '');
+    const newPath = this.router.getFile(
+      path.replace(new RegExp(`^/${local}`), '')
+    );
     const req = request(newPath + qs, true, requestHeaders);
 
     req.then(

From 190de35f62a4bbe2d76c543a53d159e91e1f7c58 Mon Sep 17 00:00:00 2001
From: Vladimir Dementyev <dementiev.vm@gmail.com>
Date: Mon, 27 Jul 2020 16:42:52 +0300
Subject: [PATCH 3/3] specs: add cypress test for fallbackLanguages

---
 cypress/fixtures/tpl/docs.index.html         | 3 ++-
 cypress/integration/routing/fallback.spec.js | 9 +++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)
 create mode 100644 cypress/integration/routing/fallback.spec.js

diff --git a/cypress/fixtures/tpl/docs.index.html b/cypress/fixtures/tpl/docs.index.html
index a4b4c831f..3ffe35230 100644
--- a/cypress/fixtures/tpl/docs.index.html
+++ b/cypress/fixtures/tpl/docs.index.html
@@ -28,7 +28,7 @@
       alias: {
         '.*?/awesome':
           'https://raw.githubusercontent.com/docsifyjs/awesome-docsify/master/README.md',
-        '.*?/changelog':
+        '/changelog':
           'https://raw.githubusercontent.com/docsifyjs/docsify/master/CHANGELOG.md',
         '/.*/_navbar.md': '/_navbar.md',
         '/zh-cn/(.*)':
@@ -40,6 +40,7 @@
         '/es/(.*)':
           'https://raw.githubusercontent.com/docsifyjs/docs-es/master/$1'
       },
+      fallbackLanguages: ['es'],
       auto2top: true,
       coverpage: true,
       executeScript: true,
diff --git a/cypress/integration/routing/fallback.spec.js b/cypress/integration/routing/fallback.spec.js
new file mode 100644
index 000000000..2e9951102
--- /dev/null
+++ b/cypress/integration/routing/fallback.spec.js
@@ -0,0 +1,9 @@
+context('config.fallbackLanguages', () => {
+  it('fallbacks respecting aliases', () => {
+    cy.visit('http://localhost:3000/#/es/');
+
+    cy.get('.sidebar-nav').contains('Changelog').click();
+
+    cy.get('#main').should('contain', 'Bug Fixes');
+  })
+});