1 files changed, 31 insertions, 13 deletions

diff --git a/src/librustdoc/html/static/js/source-script.js b/src/librustdoc/html/static/js/source-script.js
index 1e9bfa5cc89..8286e9201e6 100644
--- a/src/librustdoc/html/static/js/source-script.js
+++ b/src/librustdoc/html/static/js/source-script.js
@@ -10,7 +10,11 @@
 (function() {
 
 const rootPath = document.getElementById("rustdoc-vars").attributes["data-root-path"].value;
-let oldScrollPosition = 0;
+let oldScrollPosition = null;
+
+const NAME_OFFSET = 0;
+const DIRS_OFFSET = 1;
+const FILES_OFFSET = 2;
 
 function closeSidebarIfMobile() {
     if (window.innerWidth < window.RUSTDOC_MOBILE_BREAKPOINT) {
@@ -24,16 +28,16 @@ function createDirEntry(elem, parent, fullPath, hasFoundFile) {
 
     dirEntry.className = "dir-entry";
 
-    fullPath += elem["name"] + "/";
+    fullPath += elem[NAME_OFFSET] + "/";
 
-    summary.innerText = elem["name"];
+    summary.innerText = elem[NAME_OFFSET];
     dirEntry.appendChild(summary);
 
     const folders = document.createElement("div");
     folders.className = "folders";
-    if (elem.dirs) {
-        for (const dir of elem.dirs) {
-            if (createDirEntry(dir, folders, fullPath, hasFoundFile)) {
+    if (elem[DIRS_OFFSET]) {
+        for (const dir of elem[DIRS_OFFSET]) {
+            if (createDirEntry(dir, folders, fullPath, false)) {
                 dirEntry.open = true;
                 hasFoundFile = true;
             }
@@ -43,8 +47,8 @@ function createDirEntry(elem, parent, fullPath, hasFoundFile) {
 
     const files = document.createElement("div");
     files.className = "files";
-    if (elem.files) {
-        for (const file_text of elem.files) {
+    if (elem[FILES_OFFSET]) {
+        for (const file_text of elem[FILES_OFFSET]) {
             const file = document.createElement("a");
             file.innerText = file_text;
             file.href = rootPath + "src/" + fullPath + file_text + ".html";
@@ -71,18 +75,21 @@ function toggleSidebar() {
             oldScrollPosition = window.scrollY;
             document.body.style.position = "fixed";
             document.body.style.top = `-${oldScrollPosition}px`;
+        } else {
+            oldScrollPosition = null;
         }
         addClass(document.documentElement, "source-sidebar-expanded");
         child.innerText = "<";
         updateLocalStorage("source-sidebar-show", "true");
     } else {
-        if (window.innerWidth < window.RUSTDOC_MOBILE_BREAKPOINT) {
+        if (window.innerWidth < window.RUSTDOC_MOBILE_BREAKPOINT && oldScrollPosition !== null) {
             // This is to keep the scroll position on mobile.
             document.body.style.position = "";
             document.body.style.top = "";
             // The scroll position is lost when resetting the style, hence why we store it in
-            // `oldScroll`.
+            // `oldScrollPosition`.
             window.scrollTo(0, oldScrollPosition);
+            oldScrollPosition = null;
         }
         removeClass(document.documentElement, "source-sidebar-expanded");
         child.innerText = ">";
@@ -90,6 +97,17 @@ function toggleSidebar() {
     }
 }
 
+window.addEventListener("resize", () => {
+    if (window.innerWidth >= window.RUSTDOC_MOBILE_BREAKPOINT && oldScrollPosition !== null) {
+        // If the user opens the sidebar in "mobile" mode, and then grows the browser window,
+        // we need to switch away from mobile mode and make the main content area scrollable.
+        document.body.style.position = "";
+        document.body.style.top = "";
+        window.scrollTo(0, oldScrollPosition);
+        oldScrollPosition = null;
+    }
+});
+
 function createSidebarToggle() {
     const sidebarToggle = document.createElement("div");
     sidebarToggle.id = "sidebar-toggle";
@@ -125,7 +143,7 @@ function createSourceSidebar() {
     title.innerText = "Files";
     sidebar.appendChild(title);
     Object.keys(sourcesIndex).forEach(key => {
-        sourcesIndex[key].name = key;
+        sourcesIndex[key][NAME_OFFSET] = key;
         hasFoundFile = createDirEntry(sourcesIndex[key], sidebar, "",
             hasFoundFile);
     });
@@ -165,7 +183,7 @@ function highlightSourceLines(match) {
     if (x) {
         x.scrollIntoView();
     }
-    onEachLazy(document.getElementsByClassName("line-numbers"), e => {
+    onEachLazy(document.getElementsByClassName("src-line-numbers"), e => {
         onEachLazy(e.getElementsByTagName("span"), i_e => {
             removeClass(i_e, "line-highlighted");
         });
@@ -227,7 +245,7 @@ window.addEventListener("hashchange", () => {
     }
 });
 
-onEachLazy(document.getElementsByClassName("line-numbers"), el => {
+onEachLazy(document.getElementsByClassName("src-line-numbers"), el => {
     el.addEventListener("click", handleSourceHighlight);
 });