From 97c9677d7db805d95726875c043bb11b72a97f95 Mon Sep 17 00:00:00 2001
From: Chad Stearns <chad@humio.com>
Date: Mon, 20 Jan 2020 14:31:22 -0500
Subject: [PATCH] Include references in branch output

---
 src/can/expr.rs | 34 ++++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/src/can/expr.rs b/src/can/expr.rs
index ac4af8ad69..86a41fbae8 100644
--- a/src/can/expr.rs
+++ b/src/can/expr.rs
@@ -795,24 +795,30 @@ fn canonicalize_when_branch<'a>(
         &mut shadowable_idents,
     );
 
-    let loc_can_guard = match &loc_pattern.guard {
+    match &loc_pattern.guard {
         Some(guard) => {
-            let (can_guard, _) =
+            let (can_guard, guard_out) =
                 canonicalize_expr(env, var_store, &mut scope, region, &guard.value);
-            Some(can_guard)
+
+            (
+                WhenPattern {
+                    pattern: loc_can_pattern,
+                    guard: Some(can_guard),
+                },
+                can_expr,
+                branch_output.references.union(guard_out.references),
+            )
         }
 
-        None => None,
-    };
-
-    (
-        WhenPattern {
-            pattern: loc_can_pattern,
-            guard: loc_can_guard,
-        },
-        can_expr,
-        branch_output.references,
-    )
+        None => (
+            WhenPattern {
+                pattern: loc_can_pattern,
+                guard: None,
+            },
+            can_expr,
+            branch_output.references,
+        ),
+    }
 }
 
 pub fn union_pairs<'a, K, V, I>(mut map: ImMap<K, V>, pairs: I) -> ImMap<K, V>