3 files changed, 88 insertions, 2 deletions
diff --git a/core/config/project_settings.cpp b/core/config/project_settings.cpp
index 336f95c925..21a802cb78 100644
--- a/core/config/project_settings.cpp
+++ b/core/config/project_settings.cpp
@@ -41,6 +41,9 @@
 #include "core/os/keyboard.h"
 #include "core/os/os.h"
 #include "core/variant/variant_parser.h"
+#include "core/version.h"
+
+#include "modules/modules_enabled.gen.h" // For mono.
 
 const String ProjectSettings::PROJECT_DATA_DIR_NAME_SUFFIX = "godot";
 
@@ -66,6 +69,69 @@ String ProjectSettings::get_imported_files_path() const {
 	return get_project_data_path().plus_file("imported");
 }
 
+// Returns the features that a project must have when opened with this build of Godot.
+// This is used by the project manager to provide the initial_settings for config/features.
+const PackedStringArray ProjectSettings::get_required_features() {
+	PackedStringArray features = PackedStringArray();
+	features.append(VERSION_BRANCH);
+#ifdef REAL_T_IS_DOUBLE
+	features.append("Double Precision");
+#endif
+	return features;
+}
+
+// Returns the features supported by this build of Godot. Includes all required features.
+const PackedStringArray ProjectSettings::_get_supported_features() {
+	PackedStringArray features = get_required_features();
+#ifdef MODULE_MONO_ENABLED
+	features.append("C#");
+#endif
+	// Allow pinning to a specific patch number or build type by marking
+	// them as supported. They're only used if the user adds them manually.
+	features.append(VERSION_BRANCH "." _MKSTR(VERSION_PATCH));
+	features.append(VERSION_FULL_CONFIG);
+	features.append(VERSION_FULL_BUILD);
+	// For now, assume Vulkan is always supported.
+	// This should be removed if it's possible to build the editor without Vulkan.
+	features.append("Vulkan Clustered");
+	features.append("Vulkan Mobile");
+	return features;
+}
+
+// Returns the features that this project needs but this build of Godot lacks.
+const PackedStringArray ProjectSettings::get_unsupported_features(const PackedStringArray &p_project_features) {
+	PackedStringArray unsupported_features = PackedStringArray();
+	PackedStringArray supported_features = singleton->_get_supported_features();
+	for (int i = 0; i < p_project_features.size(); i++) {
+		if (!supported_features.has(p_project_features[i])) {
+			unsupported_features.append(p_project_features[i]);
+		}
+	}
+	unsupported_features.sort();
+	return unsupported_features;
+}
+
+// Returns the features that both this project has and this build of Godot has, ensuring required features exist.
+const PackedStringArray ProjectSettings::_trim_to_supported_features(const PackedStringArray &p_project_features) {
+	// Remove unsupported features if present.
+	PackedStringArray features = PackedStringArray(p_project_features);
+	PackedStringArray supported_features = _get_supported_features();
+	for (int i = p_project_features.size() - 1; i > -1; i--) {
+		if (!supported_features.has(p_project_features[i])) {
+			features.remove_at(i);
+		}
+	}
+	// Add required features if not present.
+	PackedStringArray required_features = get_required_features();
+	for (int i = 0; i < required_features.size(); i++) {
+		if (!features.has(required_features[i])) {
+			features.append(required_features[i]);
+		}
+	}
+	features.sort();
+	return features;
+}
+
 String ProjectSettings::localize_path(const String &p_path) const {
 	if (resource_path.is_empty() || p_path.begins_with("res://") || p_path.begins_with("user://") ||
 			(p_path.is_absolute_path() && !p_path.begins_with(resource_path))) {
@@ -635,6 +701,11 @@ Error ProjectSettings::_load_settings_text(const String &p_path) {
 			} else {
 				if (section == String()) {
 					set(assign, value);
+				} else if (section == "application" && assign == "config/features") {
+					const PackedStringArray project_features_untrimmed = value;
+					const PackedStringArray project_features = _trim_to_supported_features(project_features_untrimmed);
+					set("application/config/features", project_features);
+					save();
 				} else {
 					set(section + "/" + assign, value);
 				}
@@ -666,6 +737,13 @@ Error ProjectSettings::_load_settings_text_or_binary(const String &p_text_path,
 	return err;
 }
 
+Error ProjectSettings::load_custom(const String &p_path) {
+	if (p_path.ends_with(".binary")) {
+		return _load_settings_binary(p_path);
+	}
+	return _load_settings_text(p_path);
+}
+
 int ProjectSettings::get_order(const String &p_name) const {
 	ERR_FAIL_COND_V_MSG(!props.has(p_name), -1, "Request for nonexistent project setting: " + p_name + ".");
 	return props[p_name].order;
diff --git a/core/config/project_settings.h b/core/config/project_settings.h
index aaa8e383f7..2d8ec76b7a 100644
--- a/core/config/project_settings.h
+++ b/core/config/project_settings.h
@@ -48,6 +48,8 @@ public:
 		//properties that are not for built in values begin from this value, so builtin ones are displayed first
 		NO_BUILTIN_ORDER_BASE = 1 << 16
 	};
+	const static PackedStringArray get_required_features();
+	const static PackedStringArray get_unsupported_features(const PackedStringArray &p_project_features);
 
 	struct AutoloadInfo {
 		StringName name;
@@ -111,6 +113,9 @@ protected:
 
 	Error _save_custom_bnd(const String &p_file);
 
+	const static PackedStringArray _get_supported_features();
+	const static PackedStringArray _trim_to_supported_features(const PackedStringArray &p_project_features);
+
 	void _convert_to_last_version(int p_from_version);
 
 	bool _load_resource_pack(const String &p_pack, bool p_replace_files = true, int p_offset = 0);
@@ -125,7 +130,7 @@ protected:
 	static void _bind_methods();
 
 public:
-	static const int CONFIG_VERSION = 4;
+	static const int CONFIG_VERSION = 5;
 
 	void set_setting(const String &p_setting, const Variant &p_value);
 	Variant get_setting(const String &p_setting) const;
@@ -158,6 +163,7 @@ public:
 
 	Error setup(const String &p_path, const String &p_main_pack, bool p_upwards = false, bool p_ignore_override = false);
 
+	Error load_custom(const String &p_path);
 	Error save_custom(const String &p_path = "", const CustomMap &p_custom = CustomMap(), const Vector<String> &p_custom_features = Vector<String>(), bool p_merge_with_current = true);
 	Error save();
 	void set_custom_property_info(const String &p_prop, const PropertyInfo &p_info);
diff --git a/core/io/config_file.cpp b/core/io/config_file.cpp
index 49fa73dab2..33f992e153 100644
--- a/core/io/config_file.cpp
+++ b/core/io/config_file.cpp
@@ -183,7 +183,9 @@ Error ConfigFile::_internal_save(FileAccess *file) {
 		if (E != values.front()) {
 			file->store_string("\n");
 		}
-		file->store_string("[" + E.key() + "]\n\n");
+		if (E.key() != "") {
+			file->store_string("[" + E.key() + "]\n\n");
+		}
 
 		for (OrderedHashMap<String, Variant>::Element F = E.get().front(); F; F = F.next()) {
 			String vstr;