Rollup merge of #98806 - GuillaumeGomez:decl-trailing-whitespace, r=notriddle

Fix long declaration trailing whitespace

Fixes https://github.com/rust-lang/rust/issues/98803.

Interestingly enough, it even simplifies the code a bit.

r? `@notriddle`

4 files changed, 42 insertions, 9 deletions

diff --git a/src/librustdoc/html/format.rs b/src/librustdoc/html/format.rs
index 056eda089c1..5584ecd287a 100644
--- a/src/librustdoc/html/format.rs
+++ b/src/librustdoc/html/format.rs
@@ -1283,10 +1283,6 @@ impl clean::FnDecl {
         let mut args = Buffer::html();
         let mut args_plain = Buffer::new();
         for (i, input) in self.inputs.values.iter().enumerate() {
-            if i == 0 {
-                args.push_str("<br>");
-            }
-
             if let Some(selfty) = input.to_self() {
                 match selfty {
                     clean::SelfValue => {
@@ -1312,8 +1308,7 @@ impl clean::FnDecl {
                 }
             } else {
                 if i > 0 {
-                    args.push_str(" <br>");
-                    args_plain.push_str(" ");
+                    args.push_str("<br>");
                 }
                 if input.is_const {
                     args.push_str("const ");
@@ -1360,13 +1355,14 @@ impl clean::FnDecl {
             let full_pad = format!("<br>{}", "&nbsp;".repeat(indent + 4));
             let close_pad = format!("<br>{}", "&nbsp;".repeat(indent));
             format!(
-                "({args}{close}){arrow}",
+                "({pad}{args}{close}){arrow}",
+                pad = if self.inputs.values.is_empty() { "" } else { &full_pad },
                 args = args.replace("<br>", &full_pad),
                 close = close_pad,
                 arrow = arrow
             )
         } else {
-            format!("({args}){arrow}", args = args.replace("<br>", ""), arrow = arrow)
+            format!("({args}){arrow}", args = args.replace("<br>", " "), arrow = arrow)
         };
 
         if f.alternate() {
diff --git a/src/test/rustdoc/assoc-types.rs b/src/test/rustdoc/assoc-types.rs
index d9e4ffab1c7..a9e5b8d0019 100644
--- a/src/test/rustdoc/assoc-types.rs
+++ b/src/test/rustdoc/assoc-types.rs
@@ -2,7 +2,7 @@
 
 // @has assoc_types/trait.Index.html
 pub trait Index<I: ?Sized> {
-        // @has - '//*[@id="associatedtype.Output"]//h4[@class="code-header"]' 'type Output: ?Sized'
+    // @has - '//*[@id="associatedtype.Output"]//h4[@class="code-header"]' 'type Output: ?Sized'
     type Output: ?Sized;
     // @has - '//*[@id="tymethod.index"]//h4[@class="code-header"]' \
     //      "fn index<'a>(&'a self, index: I) -> &'a Self::Output"
diff --git a/src/test/rustdoc/decl-trailing-whitespace.declaration.html b/src/test/rustdoc/decl-trailing-whitespace.declaration.html
new file mode 100644
index 00000000000..e60caaeff38
--- /dev/null
+++ b/src/test/rustdoc/decl-trailing-whitespace.declaration.html
@@ -0,0 +1,7 @@
+<code>pub trait Write {
+    fn <a href="#tymethod.poll_write" class="fnname">poll_write</a>(<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;self: <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;cx: &amp;mut <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;buf: &amp;mut [<a class="primitive" href="{{channel}}/std/primitive.usize.html">usize</a>]<br />&#160;&#160;&#160;&#160;) -&gt; <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="enum" href="{{channel}}/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="primitive" href="{{channel}}/std/primitive.usize.html">usize</a>, <a class="struct" href="struct.Error.html" title="struct foo::Error">Error</a>&gt;&gt;;
+<span class="item-spacer" />    fn <a href="#tymethod.poll_flush" class="fnname">poll_flush</a>(<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;self: <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;cx: &amp;mut <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;<br />&#160;&#160;&#160;&#160;) -&gt; <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="enum" href="{{channel}}/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="primitive" href="{{channel}}/std/primitive.unit.html">()</a>, <a class="struct" href="struct.Error.html" title="struct foo::Error">Error</a>&gt;&gt;;
+<span class="item-spacer" />    fn <a href="#tymethod.poll_close" class="fnname">poll_close</a>(<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;self: <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;cx: &amp;mut <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;<br />&#160;&#160;&#160;&#160;) -&gt; <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="enum" href="{{channel}}/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="primitive" href="{{channel}}/std/primitive.unit.html">()</a>, <a class="struct" href="struct.Error.html" title="struct foo::Error">Error</a>&gt;&gt;;
+
+    fn <a href="#method.poll_write_vectored" class="fnname">poll_write_vectored</a>(<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;self: <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;cx: &amp;mut <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;bufs: &amp;[<a class="primitive" href="{{channel}}/std/primitive.usize.html">usize</a>]<br />&#160;&#160;&#160;&#160;) -&gt; <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="enum" href="{{channel}}/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="primitive" href="{{channel}}/std/primitive.usize.html">usize</a>, <a class="struct" href="struct.Error.html" title="struct foo::Error">Error</a>&gt;&gt; { ... }
+}</code>
diff --git a/src/test/rustdoc/decl-trailing-whitespace.rs b/src/test/rustdoc/decl-trailing-whitespace.rs
new file mode 100644
index 00000000000..46a2307abef
--- /dev/null
+++ b/src/test/rustdoc/decl-trailing-whitespace.rs
@@ -0,0 +1,30 @@
+// Regression test for <https://github.com/rust-lang/rust/issues/98803>.
+
+#![crate_name = "foo"]
+
+pub struct Error;
+
+// @has 'foo/trait.Write.html'
+
+pub trait Write {
+    // @snapshot 'declaration' - '//*[@class="docblock item-decl"]//code'
+    fn poll_write(
+        self: Option<String>,
+        cx: &mut Option<String>,
+        buf: &mut [usize]
+    ) -> Option<Result<usize, Error>>;
+    fn poll_flush(
+        self: Option<String>,
+        cx: &mut Option<String>
+    ) -> Option<Result<(), Error>>;
+    fn poll_close(
+        self: Option<String>,
+        cx: &mut Option<String>,
+    ) -> Option<Result<(), Error>>;
+
+    fn poll_write_vectored(
+        self: Option<String>,
+        cx: &mut Option<String>,
+        bufs: &[usize]
+    ) -> Option<Result<usize, Error>> {}
+}