Core: Provide comparison functions for QTypeRevision

The unspecified segment is between 0 and 1. This is because
QTypeRevision::zero(), as the default revisision needs to be smaller
than any other. At the same time we want explicitly specified non-zero
revisions to be larger than unspecified ones. Breaking this down on a
per segment level gives us the order shown here.

Change-Id: I1cca12f1180eb6f77563fb5b22c3400e118dc5e9
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

2 files changed, 78 insertions, 6 deletions

diff --git a/src/corelib/tools/qversionnumber.h b/src/corelib/tools/qversionnumber.h
index 16058bd04a..03a27548b8 100644
--- a/src/corelib/tools/qversionnumber.h
+++ b/src/corelib/tools/qversionnumber.h
@@ -416,6 +416,42 @@ inline constexpr bool operator!=(QTypeRevision lhs, QTypeRevision rhs)
     return lhs.toEncodedVersion<quint16>() != rhs.toEncodedVersion<quint16>();
 }
 
+inline constexpr bool operator<(QTypeRevision lhs, QTypeRevision rhs)
+{
+    return (!lhs.hasMajorVersion() && rhs.hasMajorVersion())
+            // non-0 major > unspecified major > major 0
+            ? rhs.majorVersion() != 0
+            : ((lhs.hasMajorVersion() && !rhs.hasMajorVersion())
+               // major 0 < unspecified major < non-0 major
+               ? lhs.majorVersion() == 0
+               : (lhs.majorVersion() != rhs.majorVersion()
+                  // both majors specified and non-0
+                  ? lhs.majorVersion() < rhs.majorVersion()
+                  : ((!lhs.hasMinorVersion() && rhs.hasMinorVersion())
+                     // non-0 minor > unspecified minor > minor 0
+                     ? rhs.minorVersion() != 0
+                     : ((lhs.hasMinorVersion() && !rhs.hasMinorVersion())
+                        // minor 0 < unspecified minor < non-0 minor
+                        ? lhs.minorVersion() == 0
+                        // both minors specified and non-0
+                        : lhs.minorVersion() < rhs.minorVersion()))));
+}
+
+inline constexpr bool operator>(QTypeRevision lhs, QTypeRevision rhs)
+{
+    return lhs != rhs && !(lhs < rhs);
+}
+
+inline constexpr bool operator<=(QTypeRevision lhs, QTypeRevision rhs)
+{
+    return lhs == rhs || lhs < rhs;
+}
+
+inline constexpr bool operator>=(QTypeRevision lhs, QTypeRevision rhs)
+{
+    return lhs == rhs || !(lhs < rhs);
+}
+
 Q_STATIC_ASSERT(sizeof(QTypeRevision) == 2);
 Q_DECLARE_TYPEINFO(QTypeRevision, Q_MOVABLE_TYPE);
 
diff --git a/tests/auto/corelib/tools/qversionnumber/tst_qversionnumber.cpp b/tests/auto/corelib/tools/qversionnumber/tst_qversionnumber.cpp
index 63a6618dab..928bd365fd 100644
--- a/tests/auto/corelib/tools/qversionnumber/tst_qversionnumber.cpp
+++ b/tests/auto/corelib/tools/qversionnumber/tst_qversionnumber.cpp
@@ -81,9 +81,10 @@ private slots:
     void serialize();
     void moveSemantics();
     void qtVersion();
-    void qPropertyRevision_data();
-    void qPropertyRevision();
-    void qPropertyRevisionTypes();
+    void qTypeRevision_data();
+    void qTypeRevision();
+    void qTypeRevisionTypes();
+    void qTypeRevisionComparison();
 };
 
 void tst_QVersionNumber::singleInstanceData()
@@ -704,7 +705,7 @@ void compileTestRevision<qint8>()
     compileTestRevisionMajorMinor<qint8>();
 }
 
-void tst_QVersionNumber::qPropertyRevision_data()
+void tst_QVersionNumber::qTypeRevision_data()
 {
     QTest::addColumn<QTypeRevision>("revision");
     QTest::addColumn<bool>("valid");
@@ -723,7 +724,7 @@ void tst_QVersionNumber::qPropertyRevision_data()
     // You must not pass them as major or minor versions, or values.
 }
 
-void tst_QVersionNumber::qPropertyRevision()
+void tst_QVersionNumber::qTypeRevision()
 {
     const QTypeRevision other = QTypeRevision::fromVersion(127, 128);
 
@@ -747,7 +748,7 @@ void tst_QVersionNumber::qPropertyRevision()
     QVERIFY(copy != other);
 }
 
-void tst_QVersionNumber::qPropertyRevisionTypes()
+void tst_QVersionNumber::qTypeRevisionTypes()
 {
     compileTestRevision<quint64>();
     compileTestRevision<qint64>();
@@ -760,6 +761,41 @@ void tst_QVersionNumber::qPropertyRevisionTypes()
     QVERIFY(maxRevision.hasMinorVersion());
 }
 
+void tst_QVersionNumber::qTypeRevisionComparison()
+{
+    const QTypeRevision revisions[] = {
+        QTypeRevision::zero(),
+        QTypeRevision::fromMajorVersion(0),
+        QTypeRevision::fromVersion(0, 1),
+        QTypeRevision::fromVersion(0, 20),
+        QTypeRevision::fromMinorVersion(0),
+        QTypeRevision(),
+        QTypeRevision::fromMinorVersion(1),
+        QTypeRevision::fromMinorVersion(20),
+        QTypeRevision::fromVersion(1, 0),
+        QTypeRevision::fromMajorVersion(1),
+        QTypeRevision::fromVersion(1, 1),
+        QTypeRevision::fromVersion(1, 20),
+        QTypeRevision::fromVersion(20, 0),
+        QTypeRevision::fromMajorVersion(20),
+        QTypeRevision::fromVersion(20, 1),
+        QTypeRevision::fromVersion(20, 20),
+    };
+
+    const int length = sizeof(revisions) / sizeof(QTypeRevision);
+
+    for (int i = 0; i < length; ++i) {
+        for (int j = 0; j < length; ++j) {
+            QCOMPARE(revisions[i] == revisions[j], i == j);
+            QCOMPARE(revisions[i] != revisions[j], i != j);
+            QCOMPARE(revisions[i] < revisions[j], i < j);
+            QCOMPARE(revisions[i] > revisions[j], i > j);
+            QCOMPARE(revisions[i] <= revisions[j], i <= j);
+            QCOMPARE(revisions[i] >= revisions[j], i >= j);
+        }
+    }
+}
+
 QTEST_APPLESS_MAIN(tst_QVersionNumber)
 
 #include "tst_qversionnumber.moc"