Rollup merge of #93038 - GuillaumeGomez:block-doc-comments, r=notriddle

Fix star handling in block doc comments

Fixes #92872.

Some extra explanation about this PR and why https://github.com/rust-lang/rust/pull/92357 created this regression: when we merge doc comment kinds for example in:

```rust
/// he
/**
* hello
*/
#[doc = "boom"]
```

We don't want to remove the empty lines between them. However, to correctly compute the "horizontal trim", we still need it, so instead, I put back a part of the "vertical trim" directly in the "horizontal trim" computation so it doesn't impact the output buffer but allows us to correctly handle the stars.

r? ``@camelid``

2 files changed, 13 insertions, 0 deletions

diff --git a/src/test/rustdoc/strip-block-doc-comments-stars.docblock.html b/src/test/rustdoc/strip-block-doc-comments-stars.docblock.html
new file mode 100644
index 00000000000..22b0b5dc47e
--- /dev/null
+++ b/src/test/rustdoc/strip-block-doc-comments-stars.docblock.html
@@ -0,0 +1,2 @@
+<div class="docblock"><p>a</p>
+</div>
\ No newline at end of file
diff --git a/src/test/rustdoc/strip-block-doc-comments-stars.rs b/src/test/rustdoc/strip-block-doc-comments-stars.rs
new file mode 100644
index 00000000000..ed2297b4fac
--- /dev/null
+++ b/src/test/rustdoc/strip-block-doc-comments-stars.rs
@@ -0,0 +1,11 @@
+#![crate_name = "foo"]
+
+// The goal of this test is to answer that it won't be generated as a list because
+// block doc comments can have their lines starting with a star.
+
+// @has foo/fn.foo.html
+// @snapshot docblock - '//*[@class="rustdoc-toggle top-doc"]//*[@class="docblock"]'
+/**
+ *     a
+ */
+pub fn foo() {}