Anchors in intra doc link

[dtolnay]

lib.rs:

/// A!
///
/// # Errors
///
/// None?
pub struct A;

/// [x][A], [y][A#errors], [z]
///
/// [z]: A#errors
pub struct B;

The documentation of B is rendered by rustdoc as ` x, [y][A#errors], z `, in which the x link correctly points to the documentation of A as expected, the y link is unrendered, and the z link points to href="A#errors".

I would expect both y and z to have href="struct.A.html#errors".

Mentioning the tracking issue: #43466

[dtolnay]

Importantly, this should take into account the deduplication of anchors on the same page. In the following, [A#errors] should go to struct.A.html#errors and [A::f#errors] should go to struct.A.html#errors-1 (which is how the anchor is deduplicated today).

/// A!
///
/// # Errors
///
/// None?
pub struct A;

impl A {
    /// f!
    ///
    /// # Errors
    ///
    /// Also none.
    pub fn f() {}
}

/// [A#errors], [A::f#errors]
pub struct B;