rustdoc: fix issues with redundant_explicit_links

src/librustdoc/passes/lint/redundant_explicit_links.rs

@@ -90,12 +90,23 @@ fn check_redundant_explicit_link<'md>(
     .into_offset_iter();
 
     while let Some((event, link_range)) = offset_iter.next() {
-        if let Event::Start(Tag::Link { link_type, dest_url, .. }) = event {
+        if let Event::Start(Tag::Link { link_type, dest_url, title, .. }) = event {
+            if !title.is_empty() {
+                // Skips if the link specifies a title, e.g. `[Option](Option "title")`,
+                // in which case the explicit link cannot be removed without also
+                // removing the title.
+                continue;
+            }
+
             let link_data = collect_link_data(&mut offset_iter);
 
-            if let Some(resolvable_link) = link_data.resolvable_link.as_ref()
-                && &link_data.display_link.replace('`', "") != resolvable_link
-            {
+            let Some(resolvable_link) = link_data.resolvable_link.as_ref() else {
+                // collect_link_data didn't return a resolvable_link
+                // most likely due to the displayed link containing inline markup
+                continue;
+            };
+
+            if &link_data.display_link.replace('`', "") != resolvable_link {
                 // Skips if display link does not match to actual
                 // resolvable link, usually happens if display link
                 // has several segments, e.g.
@@ -103,10 +114,7 @@ fn check_redundant_explicit_link<'md>(
                 continue;
             }
 
-            let explicit_link = dest_url.to_string();
-            let display_link = link_data.resolvable_link.clone()?;
-
-            if explicit_link.ends_with(&display_link) || display_link.ends_with(&explicit_link) {
+            if dest_url.ends_with(resolvable_link) || resolvable_link.ends_with(&*dest_url) {
                 match link_type {
                     LinkType::Inline | LinkType::ReferenceUnknown => {
                         check_inline_or_reference_unknown_redundancy(

tests/rustdoc-ui/lints/redundant_explicit_links-some-skipped.fixed

@@ -0,0 +1,17 @@
+//@ run-rustfix
+
+// There was a logic error in `redundant_explicit_links` that caused the lint
+// to skip all remaining links once it skipped a link containing inline markups.
+// This test asserts that the lint continues after skipping such links.
+
+#![deny(rustdoc::redundant_explicit_links)]
+
+/// [Option]
+///~^ ERROR redundant explicit link target
+///
+/// [**u8**](u8)
+/// This link should not lint.
+///
+/// [Result]
+///~^ ERROR redundant explicit link target
+pub fn func() {}

tests/rustdoc-ui/lints/redundant_explicit_links-some-skipped.rs

@@ -0,0 +1,17 @@
+//@ run-rustfix
+
+// There was a logic error in `redundant_explicit_links` that caused the lint
+// to skip all remaining links once it skipped a link containing inline markups.
+// This test asserts that the lint continues after skipping such links.
+
+#![deny(rustdoc::redundant_explicit_links)]
+
+/// [Option][Option]
+///~^ ERROR redundant explicit link target
+///
+/// [**u8**](u8)
+/// This link should not lint.
+///
+/// [Result][Result]
+///~^ ERROR redundant explicit link target
+pub fn func() {}

tests/rustdoc-ui/lints/redundant_explicit_links-some-skipped.stderr

@@ -0,0 +1,39 @@
+error: redundant explicit link target
+  --> $DIR/redundant_explicit_links-some-skipped.rs:9:14
+   |
+LL | /// [Option][Option]
+   |      ------  ^^^^^^ explicit target is redundant
+   |      |
+   |      because label contains path that resolves to same destination
+   |
+   = note: when a link's destination is not specified,
+           the label is used to resolve intra-doc links
+note: the lint level is defined here
+  --> $DIR/redundant_explicit_links-some-skipped.rs:7:9
+   |
+LL | #![deny(rustdoc::redundant_explicit_links)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+help: remove explicit link target
+   |
+LL - /// [Option][Option]
+LL + /// [Option]
+   |
+
+error: redundant explicit link target
+  --> $DIR/redundant_explicit_links-some-skipped.rs:15:14
+   |
+LL | /// [Result][Result]
+   |      ------  ^^^^^^ explicit target is redundant
+   |      |
+   |      because label contains path that resolves to same destination
+   |
+   = note: when a link's destination is not specified,
+           the label is used to resolve intra-doc links
+help: remove explicit link target
+   |
+LL - /// [Result][Result]
+LL + /// [Result]
+   |
+
+error: aborting due to 2 previous errors
+

tests/rustdoc-ui/lints/redundant_explicit_links-with-title.rs

@@ -0,0 +1,15 @@
+//@ check-pass
+
+#![deny(rustdoc::redundant_explicit_links)]
+
+/// [drop](drop "This function is not magic")
+///
+/// This link should not lint, because it specifies a link title, and it is
+/// not possible to remove the explicit link without also removing the title.
+///
+/// [Vec][vec]
+///
+/// [vec]: std::vec::Vec "A contiguous growable array type"
+///
+/// This also applies to reference-style links.
+pub fn func() {}