rustdoc: improve scroll locking in the rustdoc mobile sidebars

This commit ports the scroll locking behavior from the source sidebar to the
regular sidebar, and also fixes some bad behavior where opening a "mobile"
sidebar, and growing the viewport so that the "desktop" mode without scroll
locking is activated, could potentially leave the page stuck.

This does not affect the behavior on larger screens. Only small ones, where
the sidebar covers up the main content.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/test/rustdoc-gui/sidebar-source-code-display.goml b/src/test/rustdoc-gui/sidebar-source-code-display.goml
index fa322574fde..e4662a10ed5 100644
--- a/src/test/rustdoc-gui/sidebar-source-code-display.goml
+++ b/src/test/rustdoc-gui/sidebar-source-code-display.goml
@@ -233,6 +233,17 @@ wait-for-css: (".sidebar", {"width": "0px"})
 // The "scrollTop" property should be the same.
 assert-window-property: {"pageYOffset": "2519"}
 
+// We now check that the scroll position is restored if the window is resized.
+size: (500, 700)
+click: "#sidebar-toggle"
+wait-for-css: ("#source-sidebar", {"visibility": "visible"})
+assert-window-property: {"pageYOffset": "0"}
+size: (900, 900)
+assert-window-property: {"pageYOffset": "2519"}
+size: (500, 700)
+click: "#sidebar-toggle"
+wait-for-css: ("#source-sidebar", {"visibility": "hidden"})
+
 // We now check that opening the sidebar and clicking a link will close it.
 // The behavior here on mobile is different than the behavior on desktop,
 // but common sense dictates that if you have a list of files that fills the entire screen, and