Rollup merge of rust-lang#49652 - GuillaumeGomez:anchor-collapsed, r=QuietMisdreavus

Fix anchors issue when everything is collapsed

Fixes rust-lang#49455.

@frewsxcv does it seem good for you like this?

r? @QuietMisdreavus

Author: kennytm

src/librustdoc/html/static/main.js

@@ -56,6 +56,14 @@
         };
     }
 
+    function getPageId() {
+        var id = document.location.href.split('#')[1];
+        if (id) {
+            return id.split('?')[0].split('&')[0];
+        }
+        return null;
+    }
+
     function hasClass(elem, className) {
         if (elem && className && elem.className) {
             var elemClass = elem.className;
@@ -1643,7 +1651,7 @@
         }
     }
 
-    function toggleAllDocs() {
+    function toggleAllDocs(pageId) {
         var toggle = document.getElementById("toggle-all-docs");
         if (hasClass(toggle, "will-expand")) {
             updateLocalStorage("rustdoc-collapse", "false");
@@ -1664,12 +1672,12 @@
             toggle.title = "expand all docs";
 
             onEach(document.getElementsByClassName("collapse-toggle"), function(e) {
-                collapseDocs(e, "hide");
+                collapseDocs(e, "hide", pageId);
             });
         }
     }
 
-    function collapseDocs(toggle, mode) {
+    function collapseDocs(toggle, mode, pageId) {
         if (!toggle || !toggle.parentNode) {
             return;
         }
@@ -1745,14 +1753,18 @@
                 }
             }
 
-            var relatedDoc = toggle.parentNode;
+            var parentElem = toggle.parentNode;
+            var relatedDoc = parentElem;
             var docblock = relatedDoc.nextElementSibling;
 
             while (!hasClass(relatedDoc, "impl-items")) {
                 relatedDoc = relatedDoc.nextElementSibling;
             }
 
-            if (!relatedDoc && !hasClass(docblock, "docblock")) {
+            if ((!relatedDoc && !hasClass(docblock, "docblock")) ||
+                (pageId && onEach(relatedDoc.childNodes, function(e) {
+                    return e.id === pageId;
+                }) === true)) {
                 return;
             }
 
@@ -1782,15 +1794,15 @@
         }
     }
 
-    function autoCollapseAllImpls() {
+    function autoCollapseAllImpls(pageId) {
         // Automatically minimize all non-inherent impls
         onEach(document.getElementsByClassName('impl'), function(n) {
             // inherent impl ids are like 'impl' or impl-<number>'
             var inherent = (n.id.match(/^impl(?:-\d+)?$/) !== null);
             if (!inherent) {
                 onEach(n.childNodes, function(m) {
                     if (hasClass(m, "collapse-toggle")) {
-                        collapseDocs(m, "hide");
+                        collapseDocs(m, "hide", pageId);
                     }
                 });
             }
@@ -1900,7 +1912,7 @@
         }
     })
 
-    autoCollapseAllImpls();
+    autoCollapseAllImpls(getPageId());
 
     function createToggleWrapper() {
         var span = document.createElement('span');
@@ -2030,7 +2042,7 @@
     };
 
     if (getCurrentValue("rustdoc-collapse") === "true") {
-        toggleAllDocs();
+        toggleAllDocs(getPageId());
     }
 }());
 

src/librustdoc/html/static/storage.js

@@ -19,10 +19,11 @@ function onEach(arr, func) {
     if (arr && arr.length > 0 && func) {
         for (var i = 0; i < arr.length; i++) {
             if (func(arr[i]) === true) {
-                break;
+                return true;
             }
         }
     }
+    return false;
 }
 
 function updateLocalStorage(name, value) {