Auto merge of rust-lang#106301 - notriddle:notriddle/dir-entry, r=GuillaumeGomez

rustdoc: use the regular arrow indicator for dir-entry CSS

This mostly reverts 468acca, while still fixing the problem it fixed by using an internal list-style-position. It results in a slight change in the hover indicator, but nothing misleading.

Preview: http://notriddle.com/notriddle-rustdoc-demos/dir-entry/src/std/lib.rs.html

## Before

![image](https://user-images.githubusercontent.com/1593513/210104247-642e6df0-07d3-452a-a2ab-4c700bc22e0e.png)

## After

![image](https://user-images.githubusercontent.com/1593513/210104271-a3832784-1e4d-4516-983e-6ecb9051857b.png)

Author: bors

src/librustdoc/html/static/css/rustdoc.css

@@ -1387,31 +1387,10 @@ details.dir-entry {
 	padding-left: 4px;
 }
 
-details.dir-entry > summary::after {
-	content: " ►";
-	position: absolute;
-	left: -15px;
-	top: 0px;
-	font-size: 80%;
-	padding: 2px 0px;
-	/* set width to cover gap between arrow and text */
-	width: 25px;
-}
-
-details[open].dir-entry > summary::after {
-	content: " ▼";
-}
-
-details.dir-entry > summary::-webkit-details-marker,
-details.dir-entry > summary::marker {
-	display: none;
-}
-
 details.dir-entry > summary {
-	margin: 0 0 0 13px;
-	list-style: none;
+	margin: 0 0 0 -4px;
+	padding: 0 0 0 4px;
 	cursor: pointer;
-	position: relative;
 }
 
 details.dir-entry div.folders, details.dir-entry div.files {

src/test/rustdoc-gui/source-code-page.goml

@@ -111,8 +111,57 @@ assert-property: ("#source-sidebar details:first-of-type", {"open": "true"})
 click: "#source-sidebar details:first-of-type > summary"
 assert-property: ("#source-sidebar details:first-of-type", {"open": "false"})
 
-// Check the spacing.
-assert-css: ("#source-sidebar > details.dir-entry", {"padding-left": "4px"})
+// And open it again, since it'll be the reference we use to check positions.
+click: "#source-sidebar details:first-of-type > summary"
+assert-property: ("#source-sidebar details:first-of-type", {"open": "true"})
+
+// Check the sidebar directory entries have a marker and spacing (desktop).
+store-property: (
+    link_height,
+    "#source-sidebar > details:first-of-type.dir-entry[open] > .files > a",
+    "offsetHeight"
+)
+define-function: (
+    "check-sidebar-dir-entry",
+    (x, y),
+    [
+        ("assert", "details:first-of-type.dir-entry[open] > summary::marker"),
+        ("assert-css", ("#source-sidebar > details:first-of-type.dir-entry", {"padding-left": "4px"})),
+        // This check ensures that the summary is only one line.
+       ("assert-property", (
+            "#source-sidebar > details:first-of-type.dir-entry[open] > summary",
+            {"offsetHeight": |link_height|}
+        )),
+        ("assert-position", (
+            "#source-sidebar > details:first-of-type.dir-entry[open] > summary",
+            {"x": |x|, "y": |y|}
+        )),
+        ("assert-property", (
+            "#source-sidebar > details:first-of-type.dir-entry[open] > .files > a",
+            {"offsetHeight": |link_height|}
+        )),
+        ("assert-position", (
+            "#source-sidebar > details:first-of-type.dir-entry[open] > .files > a",
+            // left margin
+            {"x": |x| + 27, "y": |y| + |link_height|}
+        )),
+    ]
+)
+store-property: (
+    source_sidebar_title_height,
+    "#source-sidebar > .title",
+    "offsetHeight"
+)
+store-property: (
+    source_sidebar_title_y,
+    "#source-sidebar > .title",
+    "offsetTop"
+)
+call-function: ("check-sidebar-dir-entry", {
+    "x": 0,
+    // border + margin = 6
+    "y": |source_sidebar_title_y| + |source_sidebar_title_height| + 6,
+})
 
 // Check the search form
 assert-css: ("nav.sub", {"flex-direction": "row"})
@@ -125,13 +174,45 @@ assert-property: ("nav.sub form", {"offsetTop": 28, "offsetHeight": 34})
 assert-property: ("#main-content", {"offsetTop": 90})
 // 28 = 90 - 34 - 28
 
-// Now do the same check on moderately-sized mobile.
+// Now do the same check on moderately-sized, tablet mobile.
 size: (700, 700)
 assert-css: ("nav.sub", {"flex-direction": "row"})
 assert-property: ("nav.sub form", {"offsetTop": 21, "offsetHeight": 34})
 assert-property: ("#main-content", {"offsetTop": 76})
 // 21 = 76 - 34 - 21
 
-// Tiny mobile gets a different display where the logo is stacked on top.
+// Check the sidebar directory entries have a marker and spacing (tablet).
+store-property: (
+    source_sidebar_title_height,
+    "#source-sidebar > .title",
+    "offsetHeight"
+)
+store-property: (
+    source_sidebar_title_y,
+    "#source-sidebar > .title",
+    "offsetTop"
+)
+call-function: ("check-sidebar-dir-entry", {
+    "x": 0,
+    "y": |source_sidebar_title_y| + |source_sidebar_title_height| + 6,
+})
+
+// Tiny, phone mobile gets a different display where the logo is stacked on top.
 size: (450, 700)
 assert-css: ("nav.sub", {"flex-direction": "column"})
+
+// Check the sidebar directory entries have a marker and spacing (phone).
+store-property: (
+    source_sidebar_title_height,
+    "#source-sidebar > .title",
+    "offsetHeight"
+)
+store-property: (
+    source_sidebar_title_y,
+    "#source-sidebar > .title",
+    "offsetTop"
+)
+call-function: ("check-sidebar-dir-entry", {
+    "x": 0,
+    "y": |source_sidebar_title_y| + |source_sidebar_title_height| + 6,
+})