From 84eea0a5b6f74cf160863d619a0202870153cb99 Mon Sep 17 00:00:00 2001
From: calebcordry <ccordry@google.com>
Date: Fri, 16 Nov 2018 14:17:10 -0800
Subject: [PATCH] check for empty

---
 .../amp-analytics/0.1/linker-manager.js       |  4 +++-
 .../0.1/test/test-linker-manager.js           | 21 +++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/extensions/amp-analytics/0.1/linker-manager.js b/extensions/amp-analytics/0.1/linker-manager.js
index 107bbf59a007..bdc945c9eeb7 100644
--- a/extensions/amp-analytics/0.1/linker-manager.js
+++ b/extensions/amp-analytics/0.1/linker-manager.js
@@ -262,7 +262,9 @@ export class LinkerManager {
     if (this.isDomainMatch_(hostname, domains)) {
       const linkerValue = createLinker(/* version */ '1',
           this.resolvedIds_[name]);
-      el.href = addParamToUrl(href, name, linkerValue);
+      if (linkerValue) {
+        el.href = addParamToUrl(href, name, linkerValue);
+      }
     }
   }
 
diff --git a/extensions/amp-analytics/0.1/test/test-linker-manager.js b/extensions/amp-analytics/0.1/test/test-linker-manager.js
index 0ee541c45f51..0a91a1d452c9 100644
--- a/extensions/amp-analytics/0.1/test/test-linker-manager.js
+++ b/extensions/amp-analytics/0.1/test/test-linker-manager.js
@@ -187,6 +187,27 @@ describes.realWin('Linker Manager', {amp: true}, env => {
     });
   });
 
+  it('should not add params where linker value is empty', () => {
+    const config = {
+      linkers: {
+        enabled: true,
+        proxyOnly: false,
+        testLinker1: {
+          ids: {
+            gclid: '',
+          },
+        },
+      },
+    };
+
+    return new LinkerManager(ampdoc, config, null).init().then(() => {
+      expect(handlers.length).to.equal(1);
+      expect(clickAnchor('https://www.source.com/dest?a=1')).to.equal(
+          'https://www.source.com/dest?a=1'
+      );
+    });
+  });
+
   it('should generate a param valid for ingestion 5 min later', () => {
     const clock = sandbox.useFakeTimers(1533329483292);
     sandbox.stub(Date.prototype, 'getTimezoneOffset').returns(420);