Don't allow Core targets to be installed if submodule (#7379)

Co-authored-by: Kenneth Geisshirt <kenneth.geisshirt@mongodb.com>
Co-authored-by: Jørgen Edelbo <jorgen.edelbo@mongodb.com>

CMakeLists.txt

@@ -6,7 +6,7 @@ project(RealmCore)
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/tools/cmake")
 
-if(NOT CMAKE_SOURCE_DIR STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
+if(NOT DEFINED REALM_CORE_SUBMODULE_BUILD AND NOT CMAKE_SOURCE_DIR STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
     # Realm Core is being built as part of another project, likely an SDK
     set(REALM_CORE_SUBMODULE_BUILD ON)
 endif()
@@ -361,6 +361,11 @@ add_subdirectory(bindgen)
 # Install the licence and changelog files
 install(FILES LICENSE CHANGELOG.md DESTINATION "doc/realm" COMPONENT devel)
 
+# Only prepare test/install/package targets if we're not a submodule
+if(REALM_CORE_SUBMODULE_BUILD)
+    return()
+endif()
+
 # Make the project importable from the build directory
 set(REALM_EXPORTED_TARGETS
         Storage
@@ -394,11 +399,6 @@ install(FILES tools/cmake/AcquireRealmDependency.cmake
         COMPONENT devel
         )
 
-# Only prepare test/install/package targets if we're not a submodule
-if(REALM_CORE_SUBMODULE_BUILD)
-    return()
-endif()
-
 if(CMAKE_SYSTEM_NAME MATCHES "^Windows")
     # Increase the Catch2 virtual console width because our test names can be very long and they break test reports
     set(CATCH_CONFIG_CONSOLE_WIDTH 300)

bindgen/src/realm_helpers.h

@@ -179,7 +179,7 @@ struct Helpers {
     {
         size_t max_size = util::base64_decoded_size(input.size());
         std::unique_ptr<char[]> data(new char[max_size]);
-        if (auto size = util::base64_decode(input, data.get(), max_size)) {
+        if (auto size = util::base64_decode(input, {data.get(), max_size})) {
             OwnedBinaryData result(std::move(data), *size);
             return result;
         }