MDEV-22631 some test causes MTR interruption without generating summary and XML

mysql-test/lib/mtr_report.pm

@@ -473,7 +473,7 @@ sub mtr_report_stats ($$$$) {
       $comment =~ s/[\"]//g;
 
       # if a test case has to be retried it should have the result MTR_RES_FAILED in jUnit XML
-      if ($test->{'result'} eq "MTR_RES_FAILED" || $test->{'retries'}) {
+      if ($test->{'result'} eq "MTR_RES_FAILED" || $test->{'retries'} > 0) {
         my $logcontents = $test->{'logfile-failed'} || $test->{'logfile'};
 
         $xml_report .= qq(>\n\t\t\t<failure message="" type="MTR_RES_FAILED">\n<![CDATA[$logcontents]]>\n\t\t\t</failure>\n\t\t</testcase>\n);
@@ -639,6 +639,8 @@ sub mtr_error (@) {
   }
   else
   {
+    use Carp qw(cluck);
+    cluck "Error happened" if $verbose > 0;
     exit(1);
   }
 }

mysql-test/mysql-test-run.pl

@@ -769,8 +769,14 @@ sub run_test_server ($$$) {
               if ( $result->is_failed() ) {
                 my $worker_logdir= $result->{savedir};
                 my $log_file_name=dirname($worker_logdir)."/".$result->{shortname}.".log";
+
+                if (-e $log_file_name) {
                   $result->{'logfile-failed'} = mtr_lastlinesfromfile($log_file_name, 20);
-                rename $log_file_name,$log_file_name.".failed";
+                } else {
+                  $result->{'logfile-failed'} = "";
+                }
+
+                rename $log_file_name, $log_file_name.".failed";
               }
 	      delete($result->{result});
 	      $result->{retries}= $retries+1;