Disregard payloads that fail conversion from plist to json backing (#925)

Author: maciesielka

Analytics/Internal/SEGFileStorage.m

@@ -160,11 +160,18 @@ - (id _Nullable)jsonForKey:(NSString *)key
         BOOL needsConversion = NO;
         result = [self jsonFromData:data needsConversion:&needsConversion];
         if (needsConversion) {
-            [self setJSON:result forKey:key];
-            // maybe a little repetitive, but we want to recreate the same path it would
-            // take if it weren't being converted.
-            data = [self dataForKey:key];
-            result = [self jsonFromData:data needsConversion:&needsConversion];
+            @try {
+                [self setJSON:result forKey:key];
+                // maybe a little repetitive, but we want to recreate the same path it would
+                // take if it weren't being converted.
+                data = [self dataForKey:key];
+                result = [self jsonFromData:data needsConversion:&needsConversion];
+            } @catch (NSException *e) {
+                SEGLog(@"Unable to convert data from plist object to json; Exception: %@, data: %@", e, data);
+
+                [self removeKey:key];
+                result = nil;
+            }
         }
     }
     return result;

AnalyticsTests/FileStorageTest.swift

@@ -114,6 +114,19 @@ class FileStorageTest : XCTestCase {
         let dictOut = storage.dictionary(forKey: key)
         XCTAssertEqual(dictOut as? [String: String], dictIn)
     }
+
+    func testShouldRemoveDictionaryForInvalidPlistConversion() {
+        let key = "invalid.plist"
+        let dictIn: [String: Any] = [
+          "timestamp": TimeInterval.nan // `.nan` fails JSONSerialization
+        ]
+
+        let url = storage.url(forKey: key)
+        (dictIn as NSDictionary).write(to: url, atomically: true)
+        let dictOut = storage.dictionary(forKey: key)
+        XCTAssertNil(dictOut)
+        XCTAssertNil(try? url.checkResourceIsReachable())
+    }
 
     func testShouldWorkWithCrypto() {
         let url = FileStorage.applicationSupportDirectoryURL()