6 files changed, 86 insertions, 6 deletions
diff --git a/src/librustdoc/html/format.rs b/src/librustdoc/html/format.rs
index be8a2d511e9..493fdc6fb1b 100644
--- a/src/librustdoc/html/format.rs
+++ b/src/librustdoc/html/format.rs
@@ -15,11 +15,11 @@ use std::slice;
 use itertools::{Either, Itertools};
 use rustc_abi::ExternAbi;
 use rustc_ast::join_path_syms;
-use rustc_attr_data_structures::{ConstStability, StabilityLevel, StableSince};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
+use rustc_hir::{ConstStability, StabilityLevel, StableSince};
 use rustc_metadata::creader::{CStore, LoadedMacro};
 use rustc_middle::ty::{self, TyCtxt, TypingMode};
 use rustc_span::symbol::kw;
@@ -368,6 +368,8 @@ pub(crate) enum HrefError {
     Private,
     // Not in external cache, href link should be in same page
     NotInExternalCache,
+    /// Refers to an unnamable item, such as one defined within a function or const block.
+    UnnamableItem,
 }
 
 /// This function is to get the external macro path because they are not in the cache used in
@@ -479,6 +481,26 @@ fn generate_item_def_id_path(
     Ok((url_parts, shortty, fqp))
 }
 
+/// Checks if the given defid refers to an item that is unnamable, such as one defined in a const block.
+fn is_unnamable(tcx: TyCtxt<'_>, did: DefId) -> bool {
+    let mut cur_did = did;
+    while let Some(parent) = tcx.opt_parent(cur_did) {
+        match tcx.def_kind(parent) {
+            // items defined in these can be linked to, as long as they are visible
+            DefKind::Mod | DefKind::ForeignMod => cur_did = parent,
+            // items in impls can be linked to,
+            // as long as we can link to the item the impl is on.
+            // since associated traits are not a thing,
+            // it should not be possible to refer to an impl item if
+            // the base type is not namable.
+            DefKind::Impl { .. } => return false,
+            // everything else does not have docs generated for it
+            _ => return true,
+        }
+    }
+    return false;
+}
+
 fn to_module_fqp(shortty: ItemType, fqp: &[Symbol]) -> &[Symbol] {
     if shortty == ItemType::Module { fqp } else { &fqp[..fqp.len() - 1] }
 }
@@ -552,6 +574,9 @@ pub(crate) fn href_with_root_path(
         }
         _ => original_did,
     };
+    if is_unnamable(cx.tcx(), did) {
+        return Err(HrefError::UnnamableItem);
+    }
     let cache = cx.cache();
     let relative_to = &cx.current;
 
diff --git a/src/librustdoc/html/layout.rs b/src/librustdoc/html/layout.rs
index 1f92c521d46..2782e8e0058 100644
--- a/src/librustdoc/html/layout.rs
+++ b/src/librustdoc/html/layout.rs
@@ -8,6 +8,9 @@ use super::static_files::{STATIC_FILES, StaticFiles};
 use crate::externalfiles::ExternalHtml;
 use crate::html::render::{StylePath, ensure_trailing_slash};
 
+#[cfg(test)]
+mod tests;
+
 pub(crate) struct Layout {
     pub(crate) logo: String,
     pub(crate) favicon: String,
@@ -68,6 +71,13 @@ struct PageLayout<'a> {
     display_krate_version_extra: &'a str,
 }
 
+impl PageLayout<'_> {
+    /// See [`may_remove_crossorigin`].
+    fn static_root_path_may_remove_crossorigin(&self) -> bool {
+        may_remove_crossorigin(&self.static_root_path)
+    }
+}
+
 pub(crate) use crate::html::render::sidebar::filters;
 
 pub(crate) fn render<T: Display, S: Display>(
@@ -134,3 +144,22 @@ pub(crate) fn redirect(url: &str) -> String {
 </html>"##,
     )
 }
+
+/// Conservatively determines if `href` is relative to the current origin,
+/// so that `crossorigin` may be safely removed from `<link>` elements.
+pub(crate) fn may_remove_crossorigin(href: &str) -> bool {
+    // Reject scheme-relative URLs (`//example.com/`).
+    if href.starts_with("//") {
+        return false;
+    }
+    // URL is interpreted as having a scheme iff: it starts with an ascii alpha, and only
+    // contains ascii alphanumeric or `+` `-` `.` up to the `:`.
+    // https://url.spec.whatwg.org/#url-parsing
+    let has_scheme = href.split_once(':').is_some_and(|(scheme, _rest)| {
+        let mut chars = scheme.chars();
+        chars.next().is_some_and(|c| c.is_ascii_alphabetic())
+            && chars.all(|c| c.is_ascii_alphanumeric() || c == '+' || c == '-' || c == '.')
+    });
+    // Reject anything with a scheme (`http:`, etc.).
+    !has_scheme
+}
diff --git a/src/librustdoc/html/layout/tests.rs b/src/librustdoc/html/layout/tests.rs
new file mode 100644
index 00000000000..d4a19ee9abf
--- /dev/null
+++ b/src/librustdoc/html/layout/tests.rs
@@ -0,0 +1,24 @@
+#[test]
+fn test_may_remove_crossorigin() {
+    use super::may_remove_crossorigin;
+
+    assert!(may_remove_crossorigin("font.woff2"));
+    assert!(may_remove_crossorigin("/font.woff2"));
+    assert!(may_remove_crossorigin("./font.woff2"));
+    assert!(may_remove_crossorigin(":D/font.woff2"));
+    assert!(may_remove_crossorigin("../font.woff2"));
+
+    assert!(!may_remove_crossorigin("//example.com/static.files"));
+    assert!(!may_remove_crossorigin("http://example.com/static.files"));
+    assert!(!may_remove_crossorigin("https://example.com/static.files"));
+    assert!(!may_remove_crossorigin("https://example.com:8080/static.files"));
+
+    assert!(!may_remove_crossorigin("ftp://example.com/static.files"));
+    assert!(!may_remove_crossorigin("blob:http://example.com/static.files"));
+    assert!(!may_remove_crossorigin("javascript:alert('Hello, world!')"));
+    assert!(!may_remove_crossorigin("//./C:"));
+    assert!(!may_remove_crossorigin("file:////C:"));
+    assert!(!may_remove_crossorigin("file:///./C:"));
+    assert!(!may_remove_crossorigin("data:,Hello%2C%20World%21"));
+    assert!(!may_remove_crossorigin("hi...:hello"));
+}
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index 872dbbcd19e..a46253237db 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -50,12 +50,10 @@ use std::{fs, str};
 use askama::Template;
 use itertools::Either;
 use rustc_ast::join_path_syms;
-use rustc_attr_data_structures::{
-    ConstStability, DeprecatedSince, Deprecation, RustcVersion, StabilityLevel, StableSince,
-};
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet};
-use rustc_hir::Mutability;
+use rustc_hir::attrs::{DeprecatedSince, Deprecation};
 use rustc_hir::def_id::{DefId, DefIdSet};
+use rustc_hir::{ConstStability, Mutability, RustcVersion, StabilityLevel, StableSince};
 use rustc_middle::ty::print::PrintTraitRefExt;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_span::symbol::{Symbol, sym};
diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 99b3da8b2cd..c48863b4681 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -1838,6 +1838,10 @@ instead, we check that it's not a "finger" cursor.
 	border-right: 3px solid var(--target-border-color);
 }
 
+a.tooltip {
+	font-family: var(--font-family);
+}
+
 .code-header a.tooltip {
 	color: inherit;
 	margin-right: 15px;
diff --git a/src/librustdoc/html/templates/page.html b/src/librustdoc/html/templates/page.html
index 7af99e7097c..398436e3fe1 100644
--- a/src/librustdoc/html/templates/page.html
+++ b/src/librustdoc/html/templates/page.html
@@ -7,7 +7,7 @@
     <meta name="description" content="{{page.description}}"> {# #}
     <title>{{page.title}}</title> {# #}
     <script>if(window.location.protocol!=="file:") {# Hack to skip preloading fonts locally - see #98769 #}
-    document.head.insertAdjacentHTML("beforeend","{{files.source_serif_4_regular}},{{files.fira_sans_italic}},{{files.fira_sans_regular}},{{files.fira_sans_medium_italic}},{{files.fira_sans_medium}},{{files.source_code_pro_regular}},{{files.source_code_pro_semibold}}".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="{{static_root_path|safe}}${f}">`).join("")) {# #}
+    document.head.insertAdjacentHTML("beforeend","{{files.source_serif_4_regular}},{{files.fira_sans_italic}},{{files.fira_sans_regular}},{{files.fira_sans_medium_italic}},{{files.fira_sans_medium}},{{files.source_code_pro_regular}},{{files.source_code_pro_semibold}}".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2"{% if !static_root_path_may_remove_crossorigin() %} crossorigin{% endif %} href="{{static_root_path|safe}}${f}">`).join("")) {# #}
     </script> {# #}
     <link rel="stylesheet" {#+ #}
           href="{{static_root_path|safe}}{{files.normalize_css}}"> {# #}