[To rel/0.13][IOTDB-2749]Fix isPathExist check on MTree (#5259)

Author: bigreybear

server/src/main/java/org/apache/iotdb/db/metadata/mtree/MTree.java

@@ -738,8 +738,9 @@ public boolean isPathExist(PartialPath path) {
           return false;
         }
         cur = upperTemplate.getDirectNode(nodeNames[i]);
+      } else {
+        cur = cur.getChild(nodeNames[i]);
       }
-      cur = cur.getChild(nodeNames[i]);
       if (cur.isMeasurement()) {
         return i == nodeNames.length - 1;
       }

server/src/test/java/org/apache/iotdb/db/metadata/MManagerBasicTest.java

@@ -254,6 +254,36 @@ public void testAddPathAndExist() throws IllegalPathException {
       fail(e.getMessage());
     }
     assertFalse(manager.isPathExist(new PartialPath("root.1")));
+
+    assertFalse(manager.isPathExist(new PartialPath("root.template")));
+    assertFalse(manager.isPathExist(new PartialPath("root.template.d1")));
+
+    try {
+      manager.createTimeseries(
+          new PartialPath("root.template.d2"),
+          TSDataType.INT32,
+          TSEncoding.RLE,
+          TSFileDescriptor.getInstance().getConfig().getCompressor(),
+          Collections.emptyMap());
+    } catch (MetadataException e) {
+      e.printStackTrace();
+      fail(e.getMessage());
+    }
+
+    try {
+      manager.createSchemaTemplate(getCreateTemplatePlan());
+      manager.setSchemaTemplate(new SetTemplatePlan("template1", "root.template"));
+      manager.setUsingSchemaTemplate(new ActivateTemplatePlan(new PartialPath("root.template.d1")));
+    } catch (MetadataException e) {
+      e.printStackTrace();
+      fail(e.getMessage());
+    }
+
+    assertTrue(manager.isPathExist(new PartialPath("root.template.d1")));
+    assertTrue(manager.isPathExist(new PartialPath("root.template.d1.s11")));
+    assertFalse(manager.isPathExist(new PartialPath("root.template.d2.s11")));
+    assertTrue(manager.isPathExist(new PartialPath("root.template.d1.vector")));
+    assertTrue(manager.isPathExist(new PartialPath("root.template.d1.vector.s0")));
   }
 
   /**