Add failing unit test for #1686

spec/regressions.js

@@ -528,3 +528,21 @@ describe('Regressions', function() {
     });
   });
 });
+
+describe('GH-1686: Nested each with equal values skips some iterations.', function() {
+  it('each with nested equal primitive type values', function() {
+    expectTemplate(
+      '{{#each abc as | c1 |}}' +
+        '{{#each ../abc as | c2 |}}' +
+        '{{#each ../../abc as | c3 |}}' +
+        '{{c1}}{{c2}}{{c3}} {{else}}! ' +
+        '{{/each}}\n' +
+        '{{/each}}\n\n' +
+        '{{/each}}'
+    )
+      .withInput({ abc: ['A', 'B', 'C'] })
+      .toCompileTo(
+        'AAA AAB AAC \nABA ABB ABC \nACA ACB ACC \n\nBAA BAB BAC \nBBA BBB BBC \nBCA BCB BCC \n\nCAA CAB CAC \nCBA CBB CBC \nCCA CCB CCC \n\n'
+      );
+  });
+});