Auto merge of #84445 - jyn514:hidden, r=<try>

rustdoc: Hide `#text` in doc-tests

Since `#![attr]` and `#[attr]` are the only valid syntax that start with `#`, we can just special case those two tokens.

Fixes https://github.com/rust-lang/rust/issues/83284.

1 files changed, 13 insertions, 6 deletions

diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index 509f1730557..f1c9550b5ac 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -147,12 +147,19 @@ fn map_line(s: &str) -> Line<'_> {
     let trimmed = s.trim();
     if trimmed.starts_with("##") {
         Line::Shown(Cow::Owned(s.replacen("##", "#", 1)))
-    } else if let Some(stripped) = trimmed.strip_prefix("# ") {
-        // # text
-        Line::Hidden(&stripped)
-    } else if trimmed == "#" {
-        // We cannot handle '#text' because it could be #[attr].
-        Line::Hidden("")
+    } else if trimmed.starts_with('#') {
+        let mut without_hash = trimmed[1..].trim_start();
+        if without_hash.starts_with('!') {
+            // #! text
+            without_hash = without_hash[1..].trim_start_matches(' ');
+        }
+        if without_hash.starts_with('[') {
+            // #[attr] or #![attr]
+            Line::Shown(Cow::Borrowed(s))
+        } else {
+            // #text
+            Line::Hidden(without_hash)
+        }
     } else {
         Line::Shown(Cow::Borrowed(s))
     }