From 53637cdd8ed0a2255170f602b348e02211ba9387 Mon Sep 17 00:00:00 2001
From: Lukas Markeffsky <@>
Date: Sun, 31 Dec 2023 20:31:06 +0100
Subject: [PATCH 1/2] rustdoc ui: adjust tooltip z-index to be above sidebar

---
 src/librustdoc/html/static/css/rustdoc.css  |  2 +-
 tests/rustdoc-gui/tooltip-over-sidebar.goml | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 tests/rustdoc-gui/tooltip-over-sidebar.goml

diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 6e673aa77c5c8..76e9f534581c1 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -1059,7 +1059,7 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	position: absolute;
 	top: 100%;
 	right: 0;
-	z-index: 2;
+	z-index: 101;
 	margin-top: 7px;
 	border-radius: 3px;
 	border: 1px solid var(--border-color);
diff --git a/tests/rustdoc-gui/tooltip-over-sidebar.goml b/tests/rustdoc-gui/tooltip-over-sidebar.goml
new file mode 100644
index 0000000000000..71bf69787317b
--- /dev/null
+++ b/tests/rustdoc-gui/tooltip-over-sidebar.goml
@@ -0,0 +1,12 @@
+// Check that the doctest info tooltips are above the sidebar.
+go-to: "file://" + |DOC_PATH| + "/test_docs/fn.foo.html"
+move-cursor-to: ".example-wrap.ignore .tooltip"
+wait-for: ".tooltip.popover"
+
+// Move cursor to top left corner of the tooltip and check that it doesn't fade.
+move-cursor-to: ".tooltip.popover"
+wait-for: 100
+assert: ".tooltip.popover:not(.fade-out)"
+
+move-cursor-to: (0, 0)
+wait-for: ".tooltip.popover.fade-out"

From c4c4ff67fae06d17f85a84c1b2fb81863d5296aa Mon Sep 17 00:00:00 2001
From: Lukas Markeffsky <@>
Date: Sun, 31 Dec 2023 22:25:46 +0100
Subject: [PATCH 2/2] use css variable for z-index of the sidebar

and calculate the z-indices of things that go over the sidebar
---
 src/librustdoc/html/static/css/rustdoc.css | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 76e9f534581c1..c4e97ded1a058 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -14,6 +14,7 @@
 	   and on the RUSTDOC_MOBILE_BREAKPOINT */
 	--desktop-sidebar-width: 200px;
 	--src-sidebar-width: 300px;
+	--desktop-sidebar-z-index: 100;
 }
 
 /* See FiraSans-LICENSE.txt for the Fira Sans license. */
@@ -396,7 +397,7 @@ img {
 	height: 100vh;
 	top: 0;
 	left: 0;
-	z-index: 100;
+	z-index: var(--desktop-sidebar-z-index);
 }
 
 .rustdoc.src .sidebar {
@@ -416,7 +417,7 @@ img {
 	touch-action: none;
 	width: 9px;
 	cursor: col-resize;
-	z-index: 200;
+	z-index: calc(var(--desktop-sidebar-z-index) + 1);
 	position: fixed;
 	height: 100%;
 	/* make sure there's a 1px gap between the scrollbar and resize handle */
@@ -448,7 +449,6 @@ img {
 
 .sidebar-resizing .sidebar {
 	position: fixed;
-	z-index: 100;
 }
 .sidebar-resizing > body {
 	padding-left: var(--resizing-sidebar-width);
@@ -1059,7 +1059,7 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	position: absolute;
 	top: 100%;
 	right: 0;
-	z-index: 101;
+	z-index: calc(var(--desktop-sidebar-z-index) + 1);
 	margin-top: 7px;
 	border-radius: 3px;
 	border: 1px solid var(--border-color);