Enable CLANG_WARN_NULLABLE_TO_NONNULL_CONVERSION for the projects.
diff --git a/objectivec/ProtocolBuffers_OSX.xcodeproj/project.pbxproj b/objectivec/ProtocolBuffers_OSX.xcodeproj/project.pbxproj
index 08d0b7e..b17a4f4 100644
--- a/objectivec/ProtocolBuffers_OSX.xcodeproj/project.pbxproj
+++ b/objectivec/ProtocolBuffers_OSX.xcodeproj/project.pbxproj
@@ -787,6 +787,7 @@
CLANG_ANALYZER_SECURITY_INSECUREAPI_STRCPY = YES;
CLANG_STATIC_ANALYZER_MODE = deep;
CLANG_WARN_DEPRECATED_OBJC_IMPLEMENTATIONS = YES;
+ CLANG_WARN_NULLABLE_TO_NONNULL_CONVERSION = YES;
CLANG_WARN_OBJC_IMPLICIT_ATOMIC_PROPERTIES = YES;
CLANG_WARN_OBJC_MISSING_PROPERTY_SYNTHESIS = YES;
CLANG_WARN_SUSPICIOUS_IMPLICIT_CONVERSION = YES;
@@ -831,6 +832,7 @@
CLANG_ANALYZER_SECURITY_INSECUREAPI_STRCPY = YES;
CLANG_STATIC_ANALYZER_MODE = deep;
CLANG_WARN_DEPRECATED_OBJC_IMPLEMENTATIONS = YES;
+ CLANG_WARN_NULLABLE_TO_NONNULL_CONVERSION = YES;
CLANG_WARN_OBJC_IMPLICIT_ATOMIC_PROPERTIES = YES;
CLANG_WARN_OBJC_MISSING_PROPERTY_SYNTHESIS = YES;
CLANG_WARN_SUSPICIOUS_IMPLICIT_CONVERSION = YES;
