Use correct drop scopes for if expressions

1 files changed, 20 insertions, 4 deletions

diff --git a/compiler/rustc_passes/src/region.rs b/compiler/rustc_passes/src/region.rs
index c133f1a0417..7403e51c734 100644
--- a/compiler/rustc_passes/src/region.rs
+++ b/compiler/rustc_passes/src/region.rs
@@ -233,14 +233,12 @@ fn resolve_expr<'tcx>(visitor: &mut RegionResolutionVisitor<'tcx>, expr: &'tcx h
                 terminating(r.hir_id.local_id);
             }
 
-            hir::ExprKind::If(ref expr, ref then, Some(ref otherwise)) => {
-                terminating(expr.hir_id.local_id);
+            hir::ExprKind::If(_, ref then, Some(ref otherwise)) => {
                 terminating(then.hir_id.local_id);
                 terminating(otherwise.hir_id.local_id);
             }
 
-            hir::ExprKind::If(ref expr, ref then, None) => {
-                terminating(expr.hir_id.local_id);
+            hir::ExprKind::If(_, ref then, None) => {
                 terminating(then.hir_id.local_id);
             }
 
@@ -392,6 +390,24 @@ fn resolve_expr<'tcx>(visitor: &mut RegionResolutionVisitor<'tcx>, expr: &'tcx h
             }
         }
 
+        hir::ExprKind::If(ref cond, ref then, Some(ref otherwise)) => {
+            // FIXME(matthewjasper): ideally the scope we use here would only
+            // contain the condition and then expression. This works, but
+            // can result in some extra drop flags.
+            visitor.cx.var_parent = visitor.cx.parent;
+            visitor.visit_expr(cond);
+            visitor.cx.var_parent = prev_cx.var_parent;
+            visitor.visit_expr(then);
+            visitor.visit_expr(otherwise);
+        }
+
+        hir::ExprKind::If(ref cond, ref then, None) => {
+            visitor.cx.var_parent = visitor.cx.parent;
+            visitor.visit_expr(cond);
+            visitor.cx.var_parent = prev_cx.var_parent;
+            visitor.visit_expr(then);
+        }
+
         _ => intravisit::walk_expr(visitor, expr),
     }