vala: Don't make GenericType nullable by default

Allow equality between nullable and non-nullable generic-types for now

Fixes https://gitlab.gnome.org/GNOME/vala/issues/1191

4 files changed, 11 insertions, 12 deletions

diff --git a/vala/valadatatype.vala b/vala/valadatatype.vala
index fec7e9010..897eaf72c 100644
--- a/vala/valadatatype.vala
+++ b/vala/valadatatype.vala
@@ -204,7 +204,11 @@ public abstract class Vala.DataType : CodeNode {
 			return false;
 		}
 		if (type2.nullable != nullable) {
-			return false;
+			//TODO Allow equality between nullable and non-nullable generic-types
+			// This mitigation allows fixing affected source code without breaking it.
+			// It has to be removed at some point
+			var context = CodeContext.get ();
+			return !context.experimental_non_null && this is GenericType == type2 is GenericType;
 		}
 		if (type2.type_symbol != type_symbol) {
 			return false;
diff --git a/vala/valagenerictype.vala b/vala/valagenerictype.vala
index 32b32ba0e..50c713bce 100644
--- a/vala/valagenerictype.vala
+++ b/vala/valagenerictype.vala
@@ -40,8 +40,6 @@ public class Vala.GenericType : DataType {
 
 	public GenericType (TypeParameter type_parameter, SourceReference? source_reference = null) {
 		base.with_symbol (type_parameter, source_reference);
-		// type parameters are always considered nullable
-		this.nullable = true;
 	}
 
 	public override DataType copy () {
@@ -62,6 +60,9 @@ public class Vala.GenericType : DataType {
 		}
 
 		result = SemanticAnalyzer.get_actual_type (derived_instance_type, method_type_arguments, (GenericType) result, node_reference);
+		if (!result.is_non_null_simple_type ()) {
+			result.nullable = result.nullable || nullable;
+		}
 
 		return result;
 	}
@@ -77,7 +78,7 @@ public class Vala.GenericType : DataType {
 	}
 
 	public override string to_qualified_string (Scope? scope = null) {
-		return type_parameter.name;
+		return "%s%s".printf (type_parameter.name, nullable ? "?" : "");
 	}
 
 	public override Symbol? get_member (string member_name) {
diff --git a/vala/valamemberaccess.vala b/vala/valamemberaccess.vala
index 2b75adcc5..23078f25b 100644
--- a/vala/valamemberaccess.vala
+++ b/vala/valamemberaccess.vala
@@ -620,6 +620,7 @@ public class Vala.MemberAccess : Expression {
 		} else if (symbol_reference.error) {
 			//ignore previous error
 			error = true;
+			value_type = new InvalidType ();
 			return false;
 		}
 
diff --git a/vala/valasymbolresolver.vala b/vala/valasymbolresolver.vala
index 87352bd00..d029aa9a7 100644
--- a/vala/valasymbolresolver.vala
+++ b/vala/valasymbolresolver.vala
@@ -473,16 +473,9 @@ public class Vala.SymbolResolver : CodeVisitor {
 
 		type.source_reference = unresolved_type.source_reference;
 		type.value_owned = unresolved_type.value_owned;
+		type.nullable = unresolved_type.nullable;
 		sym.used = true;
 
-		if (type is GenericType) {
-			// type parameters are always considered nullable
-			// actual type argument may or may not be nullable
-			type.nullable = true;
-		} else {
-			type.nullable = unresolved_type.nullable;
-		}
-
 		type.is_dynamic = unresolved_type.is_dynamic;
 		foreach (DataType type_arg in unresolved_type.get_type_arguments ()) {
 			type.add_type_argument (type_arg);