Show summary lines on cross-crate re-exports

This removes the unnecessary `DocFragmentKind::Divider` in favor of just
using the logic I actually want in `collapse_docs`.

Author: jyn514

src/librustdoc/clean/types.rs

@@ -393,24 +393,6 @@ pub enum DocFragmentKind {
     /// A doc fragment created from a `#[doc(include="filename")]` attribute. Contains both the
     /// given filename and the file contents.
     Include { filename: String },
-    /// A doc fragment used to distinguish between documentation in different modules.
-    ///
-    /// In particular, this prevents `collapse_docs` from turning all documentation comments
-    /// into a single giant attributes even when the item is re-exported with documentation on the re-export.
-    Divider,
-}
-
-impl DocFragment {
-    /// Creates a dummy doc-fragment which divides earlier and later fragments.
-    fn divider() -> Self {
-        DocFragment {
-            line: 0,
-            span: DUMMY_SP,
-            parent_module: None,
-            doc: String::new(),
-            kind: DocFragmentKind::Divider,
-        }
-    }
 }
 
 impl<'a> FromIterator<&'a DocFragment> for String {
@@ -610,10 +592,7 @@ impl Attributes {
         // Additional documentation should be shown before the original documentation
         let other_attrs = additional_attrs
             .into_iter()
-            .map(|(attrs, id)| {
-                doc_strings.borrow_mut().push(DocFragment::divider());
-                attrs.iter().map(move |attr| (attr, Some(id)))
-            })
+            .map(|(attrs, id)| attrs.iter().map(move |attr| (attr, Some(id))))
             .flatten()
             .chain(attrs.iter().map(|attr| (attr, None)))
             .filter_map(clean_attr)

src/librustdoc/passes/collapse_docs.rs

@@ -36,7 +36,10 @@ fn collapse(doc_strings: &mut Vec<DocFragment>) {
             let curr_kind = &curr_frag.kind;
             let new_kind = &frag.kind;
 
-            if matches!(*curr_kind, DocFragmentKind::Include { .. }) || curr_kind != new_kind {
+            if matches!(*curr_kind, DocFragmentKind::Include { .. })
+                || curr_kind != new_kind
+                || curr_frag.parent_module != frag.parent_module
+            {
                 if *curr_kind == DocFragmentKind::SugaredDoc
                     || *curr_kind == DocFragmentKind::RawDoc
                 {

src/test/rustdoc/auxiliary/intra-link-reexport-additional-docs.rs

@@ -0,0 +1,6 @@
+#![crate_name = "inner"]
+
+/// Links to [f()]
+pub struct Inner;
+
+pub fn f() {}

src/test/rustdoc/auxiliary/reexport-check.rs

@@ -0,0 +1,2 @@
+/// Docs in original
+pub struct S;

src/test/rustdoc/intra-link-reexport-additional-docs.rs

@@ -1,6 +1,9 @@
+// aux-build:intra-link-reexport-additional-docs.rs
+// build-aux-docs
 #![crate_name = "foo"]
+extern crate inner;
 
-// @has foo/struct.JoinPathsError.html '//a[@href="../foo/fn.with_code.html"]' 'crate::with_code'
+// @has foo/struct.Inner.html '//a[@href="../foo/fn.with_code.html"]' 'crate::with_code'
 /// [crate::with_code]
 // @has - '//a[@href="../foo/fn.with_code.html"]' 'different text'
 /// [different text][with_code]
@@ -11,7 +14,9 @@
 #[doc = "has an attr in the way"]
 ///
 /// [reference link]: me_three
-pub use std::env::JoinPathsError;
+// Should still resolve links from the original module in that scope
+// @has - '//a[@href="../inner/fn.f.html"]' 'f()'
+pub use inner::Inner;
 
 pub fn with_code() {}
 pub fn me_too() {}

src/test/rustdoc/reexport-check.rs

@@ -1,9 +1,17 @@
+// aux-build:reexport-check.rs
 #![crate_name = "foo"]
 
+extern crate reexport_check;
+
 // @!has 'foo/index.html' '//code' 'pub use self::i32;'
 // @has 'foo/index.html' '//tr[@class="module-item"]' 'i32'
 // @has 'foo/i32/index.html'
 pub use std::i32;
 // @!has 'foo/index.html' '//code' 'pub use self::string::String;'
 // @has 'foo/index.html' '//tr[@class="module-item"]' 'String'
 pub use std::string::String;
+
+// @has 'foo/index.html' '//td[@class="docblock-short"]' 'Docs in original'
+// this is a no-op, but shows what happens if there's an attribute that isn't a doc-comment
+#[doc(inline)]
+pub use reexport_check::S;