Catch invalid simple type that was causing a crash

Although the type passes a check that's supposed to find all types
with a simple type, and appears to be of a simple type, its primitive
type is apparently null. This was causing a segmentation fault.

Apparently the code fails to correctly set the primitive type of a
pattern-type instance of a union type. Document the known limitation
by a QEXPECT_FAIL() in the test; I was unable to find where the
primitive type should be set.

Task-number: QTBUG-77620
Change-Id: I56b95ed815366c508f71b8af03b6f2a653d338c5
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

1 files changed, 23 insertions, 0 deletions

diff --git a/tests/auto/qxmlschemavalidator/tst_qxmlschemavalidator.cpp b/tests/auto/qxmlschemavalidator/tst_qxmlschemavalidator.cpp
index b128bef..51ef07d 100644
--- a/tests/auto/qxmlschemavalidator/tst_qxmlschemavalidator.cpp
+++ b/tests/auto/qxmlschemavalidator/tst_qxmlschemavalidator.cpp
@@ -74,6 +74,8 @@ private Q_SLOTS:
     void uriResolverSignature() const;
     void uriResolverDefaultValue() const;
     void uriResolver() const;
+
+    void unionCrash() const;
 };
 
 static QXmlSchema createValidSchema()
@@ -456,6 +458,27 @@ void tst_QXmlSchemaValidator::uriResolver() const
     }
 }
 
+void tst_QXmlSchemaValidator::unionCrash() const
+{
+    // Regression test for QTBUG-77620 (segfault on nullptr dereference).
+    const QString path = QFINDTESTDATA("testdata/");
+    QXmlSchema schema;
+
+    const QString filePath = path + QLatin1String("QTBUG-77620.xsd");
+
+    QFile file(filePath);
+    QVERIFY(file.open(QIODevice::ReadOnly));
+
+    schema.load(file.readAll(), QUrl(filePath));
+    QVERIFY2(schema.isValid(), "Schema should be found valid.");
+    // Validate instance
+    QXmlSchemaValidator validator(schema);
+    QEXPECT_FAIL("", "QTBUG-77620: " // Fixed crash, but not underlying problem:
+                 "the code fails to record the CUSTOM_KEY's primitive type as pattern_type", Continue);
+    QVERIFY2(validator.validate(QUrl(path + QLatin1String("QTBUG-77620.xml"))),
+             "Document should be found valid");
+}
+
 QTEST_MAIN(tst_QXmlSchemaValidator)
 
 #include "tst_qxmlschemavalidator.moc"