Auto merge of #135615 - matthiaskrgr:rollup-ra7vftt, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #131806 (Treat other items as functions for the purpose of type-based search)
 - #134980 (Location-sensitive polonius prototype: endgame)
 - #135558 (Detect if-else chains with a missing final else in type errors)
 - #135594 (fix error for when results in a rustdoc-js test are in the wrong order)
 - #135601 (Fix suggestion to convert dereference of raw pointer to ref)
 - #135604 (Expand docs for `E0207` with additional example)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 8 insertions, 0 deletions

diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/mod.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/mod.rs
index 7032f7b9d31..9778299eb19 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/infer/mod.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/infer/mod.rs
@@ -620,6 +620,14 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
             }) => {
                 let then_span = self.find_block_span_from_hir_id(then_id);
                 let else_span = self.find_block_span_from_hir_id(else_id);
+                if let hir::Node::Expr(e) = self.tcx.hir_node(else_id)
+                    && let hir::ExprKind::If(_cond, _then, None) = e.kind
+                    && else_ty.is_unit()
+                {
+                    // Account for `let x = if a { 1 } else if b { 2 };`
+                    err.note("`if` expressions without `else` evaluate to `()`");
+                    err.note("consider adding an `else` block that evaluates to the expected type");
+                }
                 err.span_label(then_span, "expected because of this");
                 if let Some(sp) = outer_span {
                     err.span_label(sp, "`if` and `else` have incompatible types");