Fix codeblocks overflow

src/librustdoc/html/markdown.rs

@@ -33,6 +33,7 @@ use std::str;
 
 use crate::clean::RenderedLink;
 use crate::doctest;
+use crate::html::escape::Escape;
 use crate::html::highlight;
 use crate::html::toc::TocBuilder;
 
@@ -207,26 +208,11 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for CodeBlocks<'_, 'a, I> {
         let should_panic;
         let ignore;
         let edition;
-        if let Some(Event::Start(Tag::CodeBlock(kind))) = event {
-            let parse_result = match kind {
-                CodeBlockKind::Fenced(ref lang) => {
-                    LangString::parse_without_check(&lang, self.check_error_codes, false)
-                }
-                CodeBlockKind::Indented => Default::default(),
-            };
-            if !parse_result.rust {
-                return Some(Event::Start(Tag::CodeBlock(kind)));
-            }
-            compile_fail = parse_result.compile_fail;
-            should_panic = parse_result.should_panic;
-            ignore = parse_result.ignore;
-            edition = parse_result.edition;
+        let kind = if let Some(Event::Start(Tag::CodeBlock(kind))) = event {
+            kind
         } else {
             return event;
-        }
-
-        let explicit_edition = edition.is_some();
-        let edition = edition.unwrap_or(self.edition);
+        };
 
         let mut origtext = String::new();
         for event in &mut self.inner {
@@ -241,6 +227,35 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for CodeBlocks<'_, 'a, I> {
         let lines = origtext.lines().filter_map(|l| map_line(l).for_html());
         let text = lines.collect::<Vec<Cow<'_, str>>>().join("\n");
 
+        let parse_result = match kind {
+            CodeBlockKind::Fenced(ref lang) => {
+                let parse_result =
+                    LangString::parse_without_check(&lang, self.check_error_codes, false);
+                if !parse_result.rust {
+                    return Some(Event::Html(
+                        format!(
+                            "<div class=\"example-wrap\">\
+                                 <pre{}>{}</pre>\
+                             </div>",
+                            format!(" class=\"language-{}\"", lang),
+                            Escape(&text),
+                        )
+                        .into(),
+                    ));
+                }
+                parse_result
+            }
+            CodeBlockKind::Indented => Default::default(),
+        };
+
+        compile_fail = parse_result.compile_fail;
+        should_panic = parse_result.should_panic;
+        ignore = parse_result.ignore;
+        edition = parse_result.edition;
+
+        let explicit_edition = edition.is_some();
+        let edition = edition.unwrap_or(self.edition);
+
         let playground_button = self.playground.as_ref().and_then(|playground| {
             let krate = &playground.crate_name;
             let url = &playground.url;

src/librustdoc/html/static/css/rustdoc.css

@@ -435,7 +435,7 @@ nav.sub {
 	border-bottom-left-radius: 5px;
 }
 
-.rustdoc:not(.source) .example-wrap > pre.rust {
+.rustdoc:not(.source) .example-wrap > pre:not(.line-number) {
 	width: 100%;
 	overflow-x: auto;
 }

src/test/rustdoc-gui/code-blocks-overflow.goml

@@ -0,0 +1,8 @@
+// This test ensures that codeblocks content don't overflow.
+goto: file://|DOC_PATH|/lib2/sub_mod/struct.Foo.html
+size: (1080, 600)
+// There should be two codeblocks: a rust one and a non-rust one.
+assert-count: (".docblock > .example-wrap", 2)
+assert: ".docblock > .example-wrap > .language-txt"
+assert: ".docblock > .example-wrap > .rust-example-rendered"
+assert-css: (".docblock > .example-wrap > pre", {"width": "796px", "overflow-x": "auto"}, ALL)

src/test/rustdoc-gui/src/lib2/lib.rs

@@ -1,3 +1,5 @@
+// ignore-tidy-linelength
+
 pub mod module {
     pub mod sub_module {
         pub mod sub_sub_module {
@@ -32,4 +34,16 @@ impl Trait for Foo {
     const Y: u32 = 0;
 }
 
+
 impl implementors::Whatever for Foo {}
+
+pub mod sub_mod {
+    /// ```txt
+    /// aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+    /// ```
+    ///
+    /// ```
+    /// aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+    /// ```
+    pub struct Foo;
+}