From 10f2dc211a4c33384a2d18025a0d2e9c5e018159 Mon Sep 17 00:00:00 2001
From: Fathy Boundjadj <fathy.boundjadj@gmail.com>
Date: Sat, 29 Sep 2018 08:22:45 +0200
Subject: [PATCH] Fix hoisting of optional require calls

---
 src/packagers/JSConcatPackager.js                    | 10 ++++++----
 .../scope-hoisting/commonjs/wrap-optional/a.js       |  6 ++++++
 test/scope-hoisting.js                               | 12 ++++++++++++
 3 files changed, 24 insertions(+), 4 deletions(-)
 create mode 100644 test/integration/scope-hoisting/commonjs/wrap-optional/a.js

diff --git a/src/packagers/JSConcatPackager.js b/src/packagers/JSConcatPackager.js
index 139ae89bf9b..2c339c90128 100644
--- a/src/packagers/JSConcatPackager.js
+++ b/src/packagers/JSConcatPackager.js
@@ -94,11 +94,13 @@ class JSConcatPackager extends Packager {
       let [source, name] = asset.cacheData.imports[identifier];
       let dep = asset.depAssets.get(asset.dependencies.get(source));
 
-      if (name === '*') {
-        this.markUsedExports(dep);
-      }
+      if (dep) {
+        if (name === '*') {
+          this.markUsedExports(dep);
+        }
 
-      this.markUsed(dep, name);
+        this.markUsed(dep, name);
+      }
     }
   }
 
diff --git a/test/integration/scope-hoisting/commonjs/wrap-optional/a.js b/test/integration/scope-hoisting/commonjs/wrap-optional/a.js
new file mode 100644
index 00000000000..54368ffd38a
--- /dev/null
+++ b/test/integration/scope-hoisting/commonjs/wrap-optional/a.js
@@ -0,0 +1,6 @@
+try {
+    output = require('noop')
+}
+catch(_) {
+    output = 42
+}
diff --git a/test/scope-hoisting.js b/test/scope-hoisting.js
index ebf2a765a6d..17ef11470b9 100644
--- a/test/scope-hoisting.js
+++ b/test/scope-hoisting.js
@@ -1053,5 +1053,17 @@ describe('scope hoisting', function() {
       let output = await run(b);
       assert.deepEqual(output, 9);
     });
+
+    it('should support optional requires', async function() {
+      let b = await bundle(
+        path.join(
+          __dirname,
+          '/integration/scope-hoisting/commonjs/wrap-optional/a.js'
+        )
+      );
+
+      let output = await run(b);
+      assert.deepEqual(output, 42);
+    });
   });
 });