--- a/devtools/client/shared/components/reps/grip.js
+++ b/devtools/client/shared/components/reps/grip.js
@@ -99,17 +99,17 @@ define(function (require, exports, modul
       let props = this.getProps(properties, indexes, truncate);
       if (truncate) {
         // There are some undisplayed props. Then display "more...".
         let objectLink = this.props.objectLink || span;
 
         props.push(Caption({
           object: objectLink({
             object: object
-          }, `${object.ownPropertyLength - max} more…`)
+          }, `${propertiesLength - max} more…`)
         }));
       }
 
       return props;
     },
 
     /**
      * Get props ordered by index.

--- a/devtools/client/shared/components/test/mochitest/test_reps_grip.html
+++ b/devtools/client/shared/components/test/mochitest/test_reps_grip.html
@@ -26,16 +26,17 @@ window.onload = Task.async(function* () 
   try {
     yield testBasic();
     yield testBooleanObject();
     yield testNumberObject();
     yield testStringObject();
     yield testProxy();
     yield testArrayBuffer();
     yield testSharedArrayBuffer();
+    yield testApplicationCache();
 
     // Test property iterator
     yield testMaxProps();
     yield testMoreThanMaxProps();
     yield testUninterestingProps();
     yield testNonEnumerableProps();
 
     // Test that properties are rendered as expected by PropRep
@@ -283,16 +284,53 @@ window.onload = Task.async(function* () 
         mode: MODE.LONG,
         expectedOutput: defaultOutput,
       }
     ];
 
     testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
   }
 
+  function testApplicationCache() {
+    // Test object: `window.applicationCache`
+    const testName = "testApplicationCache";
+
+    // Test that correct rep is chosen
+    const gripStub = getGripStub(testName);
+    const renderedRep = shallowRenderComponent(Rep, { object: gripStub });
+    is(renderedRep.type, Grip.rep, `Rep correctly selects ${Grip.rep.displayName}`);
+
+    // Test rendering
+    const defaultOutput =
+      "OfflineResourceList { status: 0, onchecking: null, onerror: null, 7 more… }";
+
+    const modeTests = [
+      {
+        mode: undefined,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: MODE.TINY,
+        expectedOutput: "OfflineResourceList",
+      },
+      {
+        mode: MODE.SHORT,
+        expectedOutput: defaultOutput,
+      },
+      {
+        mode: MODE.LONG,
+        expectedOutput: "OfflineResourceList { status: 0, onchecking: null, " +
+          "onerror: null, onnoupdate: null, ondownloading: null, onprogress: null, " +
+          "onupdateready: null, oncached: null, onobsolete: null, mozItems: [] }",
+      }
+    ];
+
+    testRepRenderModes(modeTests, testName, componentUnderTest, getGripStub(testName));
+  }
+
   function testMaxProps() {
     // Test object: `{a: "a", b: "b", c: "c"}`;
     const testName = "testMaxProps";
 
     const defaultOutput = `Object { a: "a", b: "b", c: "c" }`;
 
     const modeTests = [
       {
@@ -873,15 +911,117 @@ window.onload = Task.async(function* () 
                 "getterValue": 5,
                 "getterPrototypeLevel": 1,
                 "enumerable": false,
                 "writable": true
               }
             }
           }
         };
+      case "testApplicationCache":
+        return {
+          "type": "object",
+          "actor": "server2.conn1.child2/obj45",
+          "class": "OfflineResourceList",
+          "ownPropertyLength": 0,
+          "preview": {
+            "kind": "Object",
+            "ownProperties": {},
+            "ownPropertiesLength": 0,
+            "safeGetterValues": {
+              "status": {
+                "getterValue": 0,
+                "getterPrototypeLevel": 1,
+                "enumerable": true,
+                "writable": true
+              },
+              "onchecking": {
+                "getterValue": {
+                  "type": "null"
+                },
+                "getterPrototypeLevel": 1,
+                "enumerable": true,
+                "writable": true
+              },
+              "onerror": {
+                "getterValue": {
+                  "type": "null"
+                },
+                "getterPrototypeLevel": 1,
+                "enumerable": true,
+                "writable": true
+              },
+              "onnoupdate": {
+                "getterValue": {
+                  "type": "null"
+                },
+                "getterPrototypeLevel": 1,
+                "enumerable": true,
+                "writable": true
+              },
+              "ondownloading": {
+                "getterValue": {
+                  "type": "null"
+                },
+                "getterPrototypeLevel": 1,
+                "enumerable": true,
+                "writable": true
+              },
+              "onprogress": {
+                "getterValue": {
+                  "type": "null"
+                },
+                "getterPrototypeLevel": 1,
+                "enumerable": true,
+                "writable": true
+              },
+              "onupdateready": {
+                "getterValue": {
+                  "type": "null"
+                },
+                "getterPrototypeLevel": 1,
+                "enumerable": true,
+                "writable": true
+              },
+              "oncached": {
+                "getterValue": {
+                  "type": "null"
+                },
+                "getterPrototypeLevel": 1,
+                "enumerable": true,
+                "writable": true
+              },
+              "onobsolete": {
+                "getterValue": {
+                  "type": "null"
+                },
+                "getterPrototypeLevel": 1,
+                "enumerable": true,
+                "writable": true
+              },
+              "mozItems": {
+                "getterValue": {
+                  "type": "object",
+                  "actor": "server2.conn1.child2/obj46",
+                  "class": "DOMStringList",
+                  "extensible": true,
+                  "frozen": false,
+                  "sealed": false,
+                  "ownPropertyLength": 0,
+                  "preview": {
+                    "kind": "ArrayLike",
+                    "length": 0
+                  }
+                },
+                "getterPrototypeLevel": 1,
+                "enumerable": true,
+                "writable": true
+              }
+            }
+          }
+        };
     }
   }
 });
 </script>
 </pre>
 </body>
 </html>