Added handling for preferredLanguages being empty

* This was reported from a Swift project

Author: jkasten2

iOS_SDK/OneSignalSDK/Source/OneSignal.m

@@ -826,7 +826,6 @@ + (void)registerUser {
                                     app_id, @"app_id",
                                     deviceModel, @"device_model",
                                     [[UIDevice currentDevice] systemVersion], @"device_os",
-                                    [[NSLocale preferredLanguages] objectAtIndex:0], @"language",
                                     [NSNumber numberWithInt:(int)[[NSTimeZone localTimeZone] secondsFromGMT]], @"timezone",
                                     [NSNumber numberWithInt:0], @"device_type",
                                     [[[UIDevice currentDevice] identifierForVendor] UUIDString], @"ad_id",
@@ -850,6 +849,10 @@ + (void)registerUser {
     }
 
 
+    NSArray* preferredLanguages = [NSLocale preferredLanguages];
+    if (preferredLanguages && [preferredLanguages count] > 0)
+        dataDic[@"language"] = [preferredLanguages objectAtIndex:0];
+    
     mLastNotificationTypes = notificationTypes;
     dataDic[@"notification_types"] = [NSNumber numberWithInt:notificationTypes];
 

iOS_SDK/OneSignalSDK/UnitTests/UnitTests.m

@@ -370,6 +370,25 @@ - (BOOL)application:(UIApplication*)application didFinishLaunchingWithOptions:(N
 
 @end
 
+@interface NSLocaleOverrider : NSObject
+@end
+
+@implementation NSLocaleOverrider
+
+static NSArray* preferredLanguagesArray;
+
++ (void)load {
+    injectStaticSelector([NSLocaleOverrider class], @selector(overriderPreferredLanguages), [NSLocale class], @selector(preferredLanguages));
+}
+
++ (NSArray<NSString*> *) overriderPreferredLanguages {
+    return preferredLanguagesArray;
+}
+
+@end
+
+
+
 
 // END - Selector Shadowing
 
@@ -393,6 +412,8 @@ - (void)setUp {
 
     lastSetCategories = nil;
 
+    preferredLanguagesArray = @[@"en-US"];
+    
     [OneSignalHelper lastMessageReceived:nil];
     OneSignalHelper.lastMessageIdFromAction = nil;
     [OneSignal setValue:nil forKeyPath:@"lastAppActiveMessageId"];
@@ -525,7 +546,7 @@ - (void)testBasicInitTest {
     XCTAssertEqualObjects(lastHTTPRequset[@"notification_types"], @7);
     XCTAssertEqualObjects(lastHTTPRequset[@"device_model"], @"x86_64");
     XCTAssertEqualObjects(lastHTTPRequset[@"device_type"], @0);
-    XCTAssertEqualObjects(lastHTTPRequset[@"language"], @"en");
+    XCTAssertEqualObjects(lastHTTPRequset[@"language"], @"en-US");
 
     // 2nd init call should not fire another on_session call.
     lastHTTPRequset = nil;
@@ -535,6 +556,13 @@ - (void)testBasicInitTest {
     XCTAssertEqual(networkRequestCount, 1);
 }
 
+// Seen a few rare crash reports where [NSLocale preferredLanguages] resturns an empty array
+- (void)testInitWithEmptyPreferredLanguages {
+    preferredLanguagesArray = @[];
+    [self initOneSignal];
+    [self runBackgroundThreads];
+}
+
 - (void)testInitOnSimulator {
     [self setCurrentNotificationPermission:false];
     [self backgroundModesDisabledInXcode];
@@ -549,7 +577,7 @@ - (void)testInitOnSimulator {
     XCTAssertEqualObjects(lastHTTPRequset[@"notification_types"], @-15);
     XCTAssertEqualObjects(lastHTTPRequset[@"device_model"], @"x86_64");
     XCTAssertEqualObjects(lastHTTPRequset[@"device_type"], @0);
-    XCTAssertEqualObjects(lastHTTPRequset[@"language"], @"en");
+    XCTAssertEqualObjects(lastHTTPRequset[@"language"], @"en-US");
 
     // 2nd init call should not fire another on_session call.
     lastHTTPRequset = nil;