Skip somer error reporting when the record type has errors

The added test cases around function/event invocations report the
following flurry of errors when only the first one is relevant and
actionable. There's little use in reporting a mismatch with "error".
Squelch them.

    error in <...>/function-invoke-mismatch-error.zeek, line 8: identifier not defined: MyEnumTypo
    error in <...>/function-invoke-mismatch-error.zeek, line 12 and error: type mismatch (M::MY_ENUM_A and error)
    error in <...>/function-invoke-mismatch-error.zeek, line 12: argument type mismatch in function call (M::to_string(M::MY_ENUM_A))
    error in <...>/function-invoke-mismatch-error.zeek, line 16 and error: type mismatch (M::MY_ENUM_B and error)
    error in <...>/function-invoke-mismatch-error.zeek, line 16: argument type mismatch in function call (M::to_string(M::MY_ENUM_B))
    error in <...>/function-invoke-mismatch-error.zeek, line 20 and error: type mismatch (M::e and error)
    error in <...>/function-invoke-mismatch-error.zeek, line 20: argument type mismatch in function call (M::to_string(M::e))

Record coercion also reports noisy errors when coercing to a type that
has errors for individual fields, type clashing with "error":

    $ zeek language/record-field-error.zeek
    error in ./language/record-coerce-error.zeek, line 8: identifier not defined: MyEnumTypo
    error in ./language/record-coerce-error.zeek, line 19 and ./language/record-coerce-error.zeek, line 5: type clash for field "e" ((coerce [$e=MY_ENUM_B, $s=test] to MyRecord) and MyEnum)

src/Expr.cc

@@ -4101,6 +4101,20 @@ ValPtr ArithCoerceExpr::Fold(Val* v) const
 	return result;
 	}
 
+// Returns true if the record type or any of its fields have an error.
+static bool record_type_has_errors(const RecordType* rt)
+	{
+	if ( IsErrorType(rt->Tag()) )
+		return true;
+
+	if ( rt->NumFields() > 0 )
+		for ( const auto* td : *rt->Types() )
+			if ( IsErrorType(td->type->Tag()) )
+				return true;
+
+	return false;
+	}
+
 RecordCoerceExpr::RecordCoerceExpr(ExprPtr arg_op, RecordTypePtr r)
 	: UnaryExpr(EXPR_RECORD_COERCE, std::move(arg_op))
 	{
@@ -4120,6 +4134,12 @@ RecordCoerceExpr::RecordCoerceExpr(ExprPtr arg_op, RecordTypePtr r)
 		RecordType* t_r = type->AsRecordType();
 		RecordType* sub_r = op->GetType()->AsRecordType();
 
+		if ( record_type_has_errors(t_r) || record_type_has_errors(sub_r) )
+			{
+			SetError();
+			return;
+			}
+
 		int map_size = t_r->NumFields();
 		map.resize(map_size, -1); // -1 = field is not mapped
 
@@ -4574,7 +4594,9 @@ CallExpr::CallExpr(ExprPtr arg_func, ListExprPtr arg_args, bool in_hook, bool _i
 		return;
 		}
 
-	if ( ! func_type->MatchesIndex(args.get()) )
+	if ( record_type_has_errors(func_type->AsFuncType()->Params()->AsRecordType()) )
+		SetError();
+	else if ( ! func_type->MatchesIndex(args.get()) )
 		SetError("argument type mismatch in function call");
 	else
 		{
@@ -4943,7 +4965,9 @@ EventExpr::EventExpr(const char* arg_name, ListExprPtr arg_args)
 		return;
 		}
 
-	if ( ! func_type->MatchesIndex(args.get()) )
+	if ( record_type_has_errors(func_type->AsFuncType()->Params()->AsRecordType()) )
+		SetError();
+	else if ( ! func_type->MatchesIndex(args.get()) )
 		SetError("argument type mismatch in event invocation");
 	else
 		{

testing/btest/Baseline/language.event-invoke-mismatch-error/out

@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/event-invoke-mismatch-error.zeek, line 8: identifier not defined: MyEnumTypo

testing/btest/Baseline/language.function-invoke-mismatch-error/out

@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/function-invoke-mismatch-error.zeek, line 8: identifier not defined: MyEnumTypo

testing/btest/Baseline/language.record-coerce-error/out

@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/record-coerce-error.zeek, line 8: identifier not defined: MyEnumTypo

testing/btest/language/event-invoke-mismatch-error.zeek

@@ -0,0 +1,21 @@
+# @TEST-DOC: Error in event declaration should not report argument mismatches at call site
+# @TEST-EXEC-FAIL: zeek -b %INPUT > out 2>&1
+# @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff out
+module M;
+
+export {
+	type MyEnum: enum { MY_ENUM_A, MY_ENUM_B };
+	global my_event: event(e: MyEnumTypo);
+}
+
+event zeek_init() {
+	event my_event(MY_ENUM_A);
+}
+
+event zeek_done() {
+	event my_event(MY_ENUM_B);
+}
+
+function helper(e: MyEnum){
+	event my_event(e);
+}

testing/btest/language/function-invoke-mismatch-error.zeek

@@ -0,0 +1,21 @@
+# @TEST-DOC: Error in function declaration should not report argument mismatches at call site
+# @TEST-EXEC-FAIL: zeek -b %INPUT > out 2>&1
+# @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff out
+module M;
+
+export {
+	type MyEnum: enum { MY_ENUM_A, MY_ENUM_B };
+	global to_string: function(e: MyEnumTypo): string;
+}
+
+event zeek_init() {
+	M::to_string(MY_ENUM_A);
+}
+
+event zeek_done() {
+	M::to_string(MY_ENUM_B);
+}
+
+function helper(e: MyEnum): string {
+	return M::to_string(e);
+}

testing/btest/language/record-coerce-error.zeek

@@ -0,0 +1,16 @@
+# @TEST-DOC: Error in Record should not show when trying to coerce to it.
+# @TEST-EXEC-FAIL: zeek -b %INPUT > out 2>&1
+# @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff out
+export {
+	type MyEnum: enum { MY_ENUM_A, MY_ENUM_B };
+
+	type MyRecord: record {
+		e: MyEnumTypo;
+		s: string;
+	};
+}
+
+event zeek_init() {
+	local r1 = MyRecord($e=MY_ENUM_B, $s="test");
+	local r2: MyRecord = [$e=MY_ENUM_B, $s="test"];
+}