增加测试用例

Author: 5herhom

flink-cdc-connect/flink-cdc-source-connectors/flink-connector-mysql-cdc/src/main/java/org/apache/flink/cdc/connectors/mysql/source/offset/BinlogOffset.java

@@ -186,40 +186,37 @@ public int compareTo(BinlogOffset that) {
         String targetGtidSetStr = that.getGtidSet();
         if (StringUtils.isNotEmpty(targetGtidSetStr)) {
             // The target offset uses GTIDs, so we ideally compare using GTIDs ...
-            if (StringUtils.isEmpty(gtidSetStr)) {
-                // The target offset did use GTIDs while this did not use GTIDs. So, we assume
-                // that this offset is older since GTIDs are often enabled but rarely disabled.
-                // And if they are disabled,
-                // it is likely that this offset would not include GTIDs as we would be trying
-                // to read the binlog of a
-                // server that no longer has GTIDs. And if they are enabled, disabled, and
-                // re-enabled, per
-                // https://dev.mysql.com/doc/refman/5.7/en/replication-gtids-failover.html
-                // all properly configured slaves that
-                // use GTIDs should always have the complete set of GTIDs copied from the master, in
-                // which case
-                // again we know that this offset not having GTIDs is before the target offset ...
-                return -1;
+            if (StringUtils.isNotEmpty(gtidSetStr)) {
+                // Both have GTIDs, so base the comparison entirely on the GTID sets.
+                GtidSet gtidSet = new GtidSet(gtidSetStr);
+                GtidSet targetGtidSet = new GtidSet(targetGtidSetStr);
+                if (!gtidSet.equals(targetGtidSet)) {
+                    // The GTIDs are not an exact match, so figure out if this is a subset of the
+                    // target offset ...
+                    return gtidSet.isContainedWithin(targetGtidSet) ? -1 : 1;
+                }
+                // The GTIDs are the same, so compare the completed events in the transaction ...
+                long restartSkipEvents = this.getRestartSkipEvents();
+                long targetRestartSkipEvents = that.getRestartSkipEvents();
+                if (restartSkipEvents != targetRestartSkipEvents) {
+                    return Long.compare(restartSkipEvents, targetRestartSkipEvents);
+                }
+                // The completed events are the same, so compare the row number ...
+                return Long.compare(this.getRestartSkipRows(), that.getRestartSkipRows());
             }
-            // Both have GTIDs, so base the comparison entirely on the GTID sets.
-            GtidSet gtidSet = new GtidSet(gtidSetStr);
-            GtidSet targetGtidSet = new GtidSet(targetGtidSetStr);
-            if (!gtidSet.equals(targetGtidSet)) {
-                // The GTIDs are not an exact match, so figure out if this is a subset of the target
-                // offset
-                // ...
-                return gtidSet.isContainedWithin(targetGtidSet) ? -1 : 1;
-            }
-
-            // The GTIDs are the same, so compare the completed events in the transaction ...
-            long restartSkipEvents = this.getRestartSkipEvents();
-            long targetRestartSkipEvents = that.getRestartSkipEvents();
-            if (restartSkipEvents != targetRestartSkipEvents) {
-                return Long.compare(restartSkipEvents, targetRestartSkipEvents);
-            }
-
-            // The completed events are the same, so compare the row number ...
-            return Long.compare(this.getRestartSkipRows(), that.getRestartSkipRows());
+            // The target offset did use GTIDs while this did not use GTIDs. So, we assume
+            // that this offset is older since GTIDs are often enabled but rarely disabled.
+            // And if they are disabled,
+            // it is likely that this offset would not include GTIDs as we would be trying
+            // to read the binlog of a
+            // server that no longer has GTIDs. And if they are enabled, disabled, and re-enabled,
+            // per
+            // https://dev.mysql.com/doc/refman/5.7/en/replication-gtids-failover.html all properly
+            // configured slaves that
+            // use GTIDs should always have the complete set of GTIDs copied from the master, in
+            // which case
+            // again we know that this offset not having GTIDs is before the target offset ...
+            return -1;
         } else if (StringUtils.isNotEmpty(gtidSetStr)) {
             // This offset has a GTID but the target offset does not, so per the previous paragraph
             // we