upgrade: fix upgrade from 4.18.1.0 to 4.18.2.0-SNAPSHOT

engine/schema/src/main/java/com/cloud/upgrade/DatabaseUpgradeChecker.java

@@ -504,4 +504,8 @@ public void updateSystemVmTemplates(Connection conn) {
             }
         }
     }
+
+    public CloudStackVersion getLatestVersion() {
+        return hierarchy.getLatestVersion();
+    }
 }

engine/schema/src/main/java/com/cloud/upgrade/DatabaseVersionHierarchy.java

@@ -88,6 +88,11 @@ public DbUpgrade[] getPath(final CloudStackVersion fromVersion, final CloudStack
             return new DbUpgrade[0];
         }
 
+        // The CloudStack version is latest or higher than latest
+        if (fromVersion.compareTo(getLatestVersion()) >= 0) {
+            return new DbUpgrade[0];
+        }
+
         // we cannot find the version specified, so get the
         // most recent one immediately before this version
         if (!contains(fromVersion)) {
@@ -184,4 +189,8 @@ public DatabaseVersionHierarchy build() {
             return new DatabaseVersionHierarchy(ImmutableList.copyOf(hierarchyBuilder));
         }
     }
+
+    public CloudStackVersion getLatestVersion() {
+        return CloudStackVersion.parse(hierarchy.get(hierarchy.size() - 1).upgrader.getUpgradedVersion());
+    }
 }

engine/schema/src/test/java/com/cloud/upgrade/DatabaseUpgradeCheckerTest.java

@@ -167,8 +167,8 @@ public void testCalculateUpgradePathUnkownDbVersion() {
         final DatabaseUpgradeChecker checker = new DatabaseUpgradeChecker();
         final DbUpgrade[] upgrades = checker.calculateUpgradePath(dbVersion, currentVersion);
         assertNotNull(upgrades);
-        assertEquals("We should have 2 upgrade steps", 2, upgrades.length);
-        assertTrue(upgrades[1] instanceof NoopDbUpgrade);
+        assertEquals("We should have 1 upgrade step", 1, upgrades.length);
+        assertTrue(upgrades[0] instanceof NoopDbUpgrade);
 
     }
 
@@ -204,4 +204,23 @@ public void testCalculateUpgradePathFromUnregisteredSecVersion() {
          assertTrue(upgrades[0] instanceof Upgrade41510to41520);
          assertTrue(upgrades[upgrades.length - 1] instanceof Upgrade41610to41700);
      }
+
+    @Test
+    public void testCalculateUpgradePathFromLatestDbVersion() {
+        final DatabaseUpgradeChecker checker = new DatabaseUpgradeChecker();
+
+        final CloudStackVersion dbVersion = checker.getLatestVersion();
+        assertNotNull(dbVersion);
+
+        final CloudStackVersion currentVersion = CloudStackVersion.parse(dbVersion.getMajorRelease() + "."
+                + dbVersion.getMinorRelease() + "."
+                + dbVersion.getPatchRelease() + "."
+                + (dbVersion.getSecurityRelease() + 1));
+        assertNotNull(currentVersion);
+
+        final DbUpgrade[] upgrades = checker.calculateUpgradePath(dbVersion, currentVersion);
+        assertNotNull(upgrades);
+        assertEquals("We should have 1 upgrade step", 1, upgrades.length);
+        assertTrue(upgrades[0] instanceof NoopDbUpgrade);
+    }
 }