IMPALA-3992: bad shell error message when running nonexistent file

Fix the error handling code and add a test.

Change-Id: Iebcf1dc8a1a08b400a2c769a9cff38ea02c8e525
Reviewed-on: http://gerrit.cloudera.org:8080/4022
Reviewed-by: Henry Robinson <henry@cloudera.com>
Tested-by: Internal Jenkins

shell/impala_shell.py

@@ -1232,7 +1232,8 @@ def execute_queries_non_interactive_mode(options):
       else:
         query_file_handle = open(options.query_file, 'r')
     except Exception, e:
-      print_to_stderr("Could not open file '%s': %s", options.query_file, e)
+      print_to_stderr("Could not open file '%s': %s" % (options.query_file, e))
+      sys.exit(1)
 
     query_text = query_file_handle.read()
   elif options.query:

tests/shell/test_shell_commandline.py

@@ -429,3 +429,6 @@ class TestImpalaShell(ImpalaTestSuite):
     assert "(Coordinator: " in results.stderr
     assert "Query progress can be monitored at: " in results.stderr
 
+  def test_missing_query_file(self):
+    result = run_impala_shell_cmd('-f nonexistent.sql', expect_success=False)
+    assert "Could not open file 'nonexistent.sql'" in result.stderr