Add test for presence of read more links

src/test/rustdoc/read-more-unneeded.rs

@@ -0,0 +1,34 @@
+// Regression test for https://github.com/rust-lang/rust/issues/105677.
+// This test ensures that the "Read more" link is only generated when
+// there is actually more documentation to read after the short summary.
+
+#![crate_name = "foo"]
+
+pub trait MyFrom {
+    /// # Hello
+    /// ## Yolo
+    /// more!
+    fn try_from1();
+    /// a
+    /// b
+    /// c
+    fn try_from2();
+    /// a
+    ///
+    /// b
+    ///
+    /// c
+    fn try_from3();
+}
+
+pub struct NonZero;
+
+// @has 'foo/struct.NonZero.html'
+impl MyFrom for NonZero {
+    // @matches - '//*[@class="docblock"]' '^Hello Read more$'
+    fn try_from1() {}
+    // @matches - '//*[@class="docblock"]' '^a\sb\sc$'
+    fn try_from2() {}
+    // @matches - '//*[@class="docblock"]' '^a Read more$'
+    fn try_from3() {}
+}

src/test/rustdoc/trait-impl.rs

@@ -30,8 +30,6 @@ impl Trait for Struct {
     // @has - '//*[@id="method.b"]/../../div[@class="docblock"]' 'These docs contain'
     // @has - '//*[@id="method.b"]/../../div[@class="docblock"]/a' 'reference link'
     // @has - '//*[@id="method.b"]/../../div[@class="docblock"]/a/@href' 'https://example.com'
-    // @has - '//*[@id="method.b"]/../../div[@class="docblock"]/a' 'Read more'
-    // @has - '//*[@id="method.b"]/../../div[@class="docblock"]/a/@href' 'trait.Trait.html#tymethod.b'
     fn b() {}
 
     // @!has - '//*[@id="method.c"]/../../div[@class="docblock"]' 'code block'