Auto merge of #119283 - GuillaumeGomez:warning-block-pos, r=notriddle

Fix display of warning block if it is first element of the top doc block

It fixes the display of the warning block "i" element in case it is the first element:

![Screenshot from 2023-12-23 11-15-48](https://github.com/rust-lang/rust/assets/3050060/99b6796e-2a09-4053-813e-84288ce76c4c)

It now looks like this:

![image](https://github.com/rust-lang/rust/assets/3050060/306b4cf1-3a7d-4681-b0cf-3e721186bfe8)

The update for the `browser-ui-test` framework is because it didn't detect correctly pseudo elements if they ended with a digit or a dash.

r? `@notriddle`

4 files changed, 20 insertions, 1 deletions

diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version b/src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version
index 50b6386a009..a2b63962ba1 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version
@@ -1 +1 @@
-0.16.10
\ No newline at end of file
+0.16.11
\ No newline at end of file
diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 6e673aa77c5..665bb5d42bc 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -1367,6 +1367,9 @@ documentation. */
 	font-weight: bold;
 	font-size: 1.25rem;
 }
+.top-doc > .docblock >.warning:first-child::before {
+	top: 20px;
+}
 
 a.test-arrow {
 	visibility: hidden;
diff --git a/tests/rustdoc-gui/src/test_docs/lib.rs b/tests/rustdoc-gui/src/test_docs/lib.rs
index 0bc777230bf..7e34178e56f 100644
--- a/tests/rustdoc-gui/src/test_docs/lib.rs
+++ b/tests/rustdoc-gui/src/test_docs/lib.rs
@@ -85,6 +85,9 @@ impl AsRef<str> for Foo {
     }
 }
 
+/// <div id="doc-warning-0" class="warning">I have warnings!</div>
+pub struct WarningStruct;
+
 /// Just a normal enum.
 ///
 /// # title!
diff --git a/tests/rustdoc-gui/warning-block.goml b/tests/rustdoc-gui/warning-block.goml
index 8832b65c4d8..10e206049f5 100644
--- a/tests/rustdoc-gui/warning-block.goml
+++ b/tests/rustdoc-gui/warning-block.goml
@@ -2,6 +2,7 @@
 go-to: "file://" + |DOC_PATH| + "/test_docs/struct.Foo.html"
 show-text: true
 
+store-value: (default_y_pos, 5)
 define-function: (
     "check-warning",
     (theme, color, border_color),
@@ -16,12 +17,18 @@ define-function: (
             "border-left": "2px solid " + |border_color|,
             "background-color": "transparent",
         })
+        store-position: ("#doc-warning-1", {"y": warn_div_y})
+        store-position: ("#doc-warning-1::before", {"y": warn_y})
+        assert: |warn_y| == |warn_div_y| + |default_y_pos|
         assert-css: ("#doc-warning-2", {
             "margin-bottom": "0px",
             "color": |color|,
             "border-left": "2px solid " + |border_color|,
             "background-color": "transparent",
         })
+        store-position: ("#doc-warning-2", {"y": warn_div_y})
+        store-position: ("#doc-warning-2::before", {"y": warn_y})
+        assert: |warn_y| == |warn_div_y| + |default_y_pos|
     },
 )
 
@@ -40,3 +47,9 @@ call-function: ("check-warning", {
     "color": "black",
     "border_color": "#ff8e00",
 })
+
+// We ensure that the warning element in the top doc is not overlaying the "[-]" button.
+go-to: "file://" + |DOC_PATH| + "/test_docs/struct.WarningStruct.html"
+store-position: ("#doc-warning-0", {"y": warn_div_y})
+store-position: ("#doc-warning-0::before", {"y": warn_y})
+assert: |warn_y| == |warn_div_y| + |default_y_pos| + 15