MXS-1926: Add test case

Added a test case that reproduces the problem and verifies that it is
solved.

maxscale-system-test/mxs1926_killed_server.cpp

@@ -0,0 +1,106 @@
+/**
+ * MXS-1926: LOAD DATA LOCAL INFILE interrupted by server shutdown
+ *
+ * https://jira.mariadb.org/browse/MXS-1926
+ */
+
+#include "testconnections.h"
+#include <stdlib.h>
+#include <thread>
+#include <fstream>
+#include <chrono>
+#include <atomic>
+
+using namespace std::chrono;
+
+typedef high_resolution_clock Clock;
+
+std::atomic<int> ROWCOUNT{10000};
+
+std::string create_tmpfile()
+{
+    char filename[] = "/tmp/data.csv.XXXXXX";
+    int fd = mkstemp(filename);
+    std::ofstream file(filename);
+    close(fd);
+
+    for (int i = 0; i < ROWCOUNT; i++)
+    {
+        file << "1, 2, 3, 4\n";
+    }
+
+    return filename;
+}
+
+void tune_rowcount(TestConnections& test)
+{
+    milliseconds dur{1};
+    test.tprintf("Tuning data size so that an insert takes 10 seconds");
+    test.maxscales->connect();
+    test.try_query(test.maxscales->conn_rwsplit[0], "SET sql_log_bin=0");
+
+    while (dur < seconds(10))
+    {
+        std::string filename = create_tmpfile();
+
+        auto start = Clock::now();
+        test.try_query(test.maxscales->conn_rwsplit[0], "LOAD DATA LOCAL INFILE '%s' INTO TABLE test.t1",
+                       filename.c_str());
+        auto end = Clock::now();
+        dur = duration_cast<milliseconds>(end - start);
+        test.try_query(test.maxscales->conn_rwsplit[0], "TRUNCATE TABLE test.t1", filename.c_str());
+
+        remove(filename.c_str());
+
+        int orig = ROWCOUNT;
+        ROWCOUNT = orig / dur.count() * 10000;
+        test.tprintf("Loading %d rows took %d ms, setting row count to %d",
+                     orig, dur.count(), ROWCOUNT.load());
+    }
+
+    test.maxscales->disconnect();
+}
+
+int main(int argc, char** argv)
+{
+    TestConnections test(argc, argv);
+
+    test.repl->connect();
+
+    // Create the table
+    execute_query(test.repl->nodes[0], "CREATE OR REPLACE TABLE test.t1 (a INT, b INT, c INT, d INT)");
+    test.repl->sync_slaves();
+
+    // Tune the amount of data so that the loading will take approximately 15 seconds
+    tune_rowcount(test);
+
+    std::string filename = create_tmpfile();
+
+    // Connect to MaxScale and load enough data so that we have
+    test.maxscales->connect();
+
+    // Disable replication of the LOAD DATA LOCAL INFILE
+    test.try_query(test.maxscales->conn_rwsplit[0], "SET sql_log_bin=0");
+
+    test.tprintf("Loading %d rows of data while stopping a slave", ROWCOUNT.load());
+    std::thread thr([&]()
+    {
+        std::this_thread::sleep_for(milliseconds(10));
+        test.repl->stop_node(3);
+        test.repl->start_node(3);
+    });
+    test.try_query(test.maxscales->conn_rwsplit[0], "LOAD DATA LOCAL INFILE '%s' INTO TABLE test.t1",
+                   filename.c_str());
+    test.tprintf("Load complete");
+    thr.join();
+
+    test.maxscales->disconnect();
+
+    // Cleanup
+    execute_query(test.repl->nodes[0], "DROP TABLE test.t1");
+    test.repl->sync_slaves();
+    test.repl->disconnect();
+
+    remove(filename.c_str());
+    return test.global_result;
+}