Set origin iterator last one if all iterators of extendable iterator …

…are empty

implemented: #360

Change-Id: I5586ea3626816c085af788830917759f653ed0c4

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>com.baidu.hugegraph</groupId>
     <artifactId>hugegraph-common</artifactId>
-    <version>1.5.6</version>
+    <version>1.5.7</version>
 
     <name>hugegraph-common</name>
     <url>https://github.com/hugegraph/hugegraph-common</url>

src/main/java/com/baidu/hugegraph/iterator/ExtendableIterator.java

@@ -94,6 +94,7 @@ protected boolean fetch() {
         Iterator<T> first = null;
         while ((first = this.itors.peekFirst()) != null && !first.hasNext()) {
             if (first == this.itors.peekLast() && this.itors.size() == 1) {
+                this.currentIterator = first;
                 // The last one
                 return false;
             }

src/main/java/com/baidu/hugegraph/version/CommonVersion.java

@@ -27,5 +27,5 @@ public class CommonVersion {
 
     // The second parameter of Version.of() is for all-in-one JAR
     public static final Version VERSION = Version.of(CommonVersion.class,
-                                                     "1.5.6");
+                                                     "1.5.7");
 }