ASYNC-212: fix expressions with nil local

Signed-off-by: Alex Miller <alex.miller@cognitect.com>
clojure · Jan 9, 2020 · 78f5ab3 · 78f5ab3
1 parent b74d475
commit 78f5ab3
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Showing 2 changed files with 13 additions and 4 deletions.
diff --git a/src/main/clojure/clojure/core/async/impl/ioc_macros.clj b/src/main/clojure/clojure/core/async/impl/ioc_macros.clj
@@ -226,8 +226,9 @@
 (defrecord RawCode [ast locals]
   IInstruction
   (reads-from [this]
-    (keep (or locals #{})
-          (map :name (-> ast :env :locals vals))))
+    (for [local (map :name (-> ast :env :locals vals))
+          :when (contains? locals local)]
+      (get locals local)))
   (writes-to [this] [(:id this)])
   (block-references [this] [])
   IEmittableInstruction
@@ -236,8 +237,7 @@
       `[~@(->> (-> ast :env :locals vals)
                (map #(select-keys % [:op :name :form]))
                (filter (fn [local]
-                         (when locals
-                           (get locals (:name local)))))
+                         (contains? locals (:name local))))
                set
                (mapcat
                 (fn [local]

diff --git a/src/test/clojure/clojure/core/async/ioc_macros_test.clj b/src/test/clojure/clojure/core/async/ioc_macros_test.clj
@@ -529,3 +529,12 @@
                 (catch UnsupportedOperationException ex
                   :unsupported)))]
     (is (= :ok resp))))
+
+(deftest ASYNC-212
+  (is (= 42
+         (<!! (go
+                (let [a nil
+                      foo (identity a)]
+                  (if foo
+                    (<! foo)
+                    42)))))))