[iotdb] branch master updated: fix SchemaQueryMergeOperator#next return null (#6592)

[zyk]

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zyk pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/iotdb.git


The following commit(s) were added to refs/heads/master by this push:
     new 9adaa84fad fix SchemaQueryMergeOperator#next return null (#6592)
9adaa84fad is described below

commit 9adaa84fad239daae319b6b6c41262cf3c05435d
Author: xinzhongtianxia <453935...@qq.com>
AuthorDate: Wed Jul 6 15:44:43 2022 +0800

    fix SchemaQueryMergeOperator#next return null (#6592)
    
    [IOTDB-3750] Fix NPE caused by SchemaQueryMergeOperator#next returning null 
#6592
---
 .../execution/operator/schema/SchemaQueryMergeOperator.java    | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git 
a/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/schema/SchemaQueryMergeOperator.java
 
b/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/schema/SchemaQueryMergeOperator.java
index 519cdce27e..4902d36fe0 100644
--- 
a/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/schema/SchemaQueryMergeOperator.java
+++ 
b/server/src/main/java/org/apache/iotdb/db/mpp/execution/operator/schema/SchemaQueryMergeOperator.java
@@ -51,16 +51,14 @@ public class SchemaQueryMergeOperator implements 
ProcessOperator {
 
   @Override
   public TsBlock next() {
-    if (children.get(currentIndex).hasNext()) {
-      return children.get(currentIndex).next();
-    } else {
-      currentIndex++;
-      return null;
-    }
+    return children.get(currentIndex).next();
   }
 
   @Override
   public boolean hasNext() {
+    while (currentIndex < children.size() && 
!children.get(currentIndex).hasNext()) {
+      currentIndex++;
+    }
     return currentIndex < children.size();
   }