From be0b109886222d2160df4c118c77e7da4ce34831 Mon Sep 17 00:00:00 2001
From: Martin Bektchiev <martin.bektchiev@progress.com>
Date: Tue, 18 Sep 2018 18:24:49 +0300
Subject: [PATCH] fix(objc-call): Don't crash when calling an optional protocol
 method

refs #978
---
 src/NativeScript/Metadata/Metadata.h    | 7 ++++++-
 src/NativeScript/ObjC/ObjCMethodCall.h  | 2 ++
 src/NativeScript/ObjC/ObjCMethodCall.mm | 8 +++++++-
 src/metadata-generator                  | 2 +-
 4 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/NativeScript/Metadata/Metadata.h b/src/NativeScript/Metadata/Metadata.h
index 09a5cc471..61cb818a7 100644
--- a/src/NativeScript/Metadata/Metadata.h
+++ b/src/NativeScript/Metadata/Metadata.h
@@ -25,13 +25,15 @@ enum MetaFlags {
     FunctionReturnsUnmanaged = 3,
     FunctionIsVariadic = 5,
     FunctionOwnsReturnedCocoaObject = 4,
+    MemberIsOptional = 0, // Mustn't equal any Method or Property flag since it can be applicable to both
     MethodIsInitializer = 1,
     MethodIsVariadic = 2,
     MethodIsNullTerminatedVariadic = 3,
     MethodOwnsReturnedCocoaObject = 4,
     MethodHasErrorOutParameter = 5,
     PropertyHasGetter = 2,
-    PropertyHasSetter = 3
+    PropertyHasSetter = 3,
+
 };
 
 /// This enum describes the possible ObjectiveC entity types.
@@ -581,6 +583,9 @@ struct VarMeta : Meta {
 };
 
 struct MemberMeta : Meta {
+    bool isOptional() const {
+        return this->flag(MetaFlags::MemberIsOptional);
+    }
 };
 
 struct MethodMeta : MemberMeta {
diff --git a/src/NativeScript/ObjC/ObjCMethodCall.h b/src/NativeScript/ObjC/ObjCMethodCall.h
index 5d9f0ce6a..920cbecd7 100644
--- a/src/NativeScript/ObjC/ObjCMethodCall.h
+++ b/src/NativeScript/ObjC/ObjCMethodCall.h
@@ -66,6 +66,8 @@ class ObjCMethodCall : public FFICall {
 
     bool _hasErrorOutParameter;
 
+    bool _isOptional;
+
     bool _isInitializer;
 
     SEL _selector;
diff --git a/src/NativeScript/ObjC/ObjCMethodCall.mm b/src/NativeScript/ObjC/ObjCMethodCall.mm
index 6633edfff..4be12b9ee 100644
--- a/src/NativeScript/ObjC/ObjCMethodCall.mm
+++ b/src/NativeScript/ObjC/ObjCMethodCall.mm
@@ -34,6 +34,7 @@
 
     Base::initializeFFI(vm, { &preInvocation, &postInvocation }, returnTypeCell, parameterTypesCells, 2);
     this->_retainsReturnedCocoaObjects = metadata->ownsReturnedCocoaObject();
+    this->_isOptional = metadata->isOptional();
     this->_isInitializer = metadata->isInitializer();
     this->_hasErrorOutParameter = metadata->hasErrorOutParameter();
 
@@ -130,7 +131,12 @@ static bool isJavaScriptDerived(JSC::JSValue value) {
         bool isInstance = !class_isMetaClass(object_getClass(target));
         NSLog(@"> %@[%@ %@]", isInstance ? @"-" : @"+", NSStringFromClass(object_getClass(target)), NSStringFromSelector(call->_selector));
 #endif
-        invocation.setArgument(0, target);
+        if (call->_isOptional && ![target respondsToSelector:call->_selector]) {
+            // Unimplemented optional method: Silently perform a dummy call to nil object
+            invocation.setArgument(0, nil);
+        } else {
+            invocation.setArgument(0, target);
+        }
         invocation.setArgument(1, call->_selector);
         invocation.function = call->_msgSend;
     }
diff --git a/src/metadata-generator b/src/metadata-generator
index 78acbc095..9790c66de 160000
--- a/src/metadata-generator
+++ b/src/metadata-generator
@@ -1 +1 @@
-Subproject commit 78acbc095d976fa99453490779e61e60949c837a
+Subproject commit 9790c66de825f16957b4274e6762615f6ea7c231