1 files changed, 43 insertions, 0 deletions
diff --git a/test/dialect/mysql.py b/test/dialect/mysql.py
index e1bd47d29..00478908e 100644
--- a/test/dialect/mysql.py
+++ b/test/dialect/mysql.py
@@ -927,6 +927,49 @@ class SQLTest(TestBase, AssertsCompiledSQL):
             self.assert_compile(cast(t.c.col, type_), expected)
 
 
+class ExecutionTest(TestBase):
+    """Various MySQL execution special cases."""
+
+    __only_on__ = 'mysql'
+
+    def test_charset_caching(self):
+        engine = engines.testing_engine()
+
+        cx = engine.connect()
+        meta = MetaData()
+
+        assert ('mysql', 'charset') not in cx.info
+        assert ('mysql', 'force_charset') not in cx.info
+
+        cx.execute(text("SELECT 1")).fetchall()
+        assert ('mysql', 'charset') not in cx.info
+
+        meta.reflect(cx)
+        assert ('mysql', 'charset') in cx.info
+
+        cx.execute(text("SET @squiznart=123"))
+        assert ('mysql', 'charset') in cx.info
+
+        # the charset invalidation is very conservative
+        cx.execute(text("SET TIMESTAMP = DEFAULT"))
+        assert ('mysql', 'charset') not in cx.info
+
+        cx.info[('mysql', 'force_charset')] = 'latin1'
+
+        assert engine.dialect._detect_charset(cx) == 'latin1'
+        assert cx.info[('mysql', 'charset')] == 'latin1'
+
+        del cx.info[('mysql', 'force_charset')]
+        del cx.info[('mysql', 'charset')]
+
+        meta.reflect(cx)
+        assert ('mysql', 'charset') in cx.info
+
+        # String execution doesn't go through the detector.
+        cx.execute("SET TIMESTAMP = DEFAULT")
+        assert ('mysql', 'charset') in cx.info
+
+
 def colspec(c):
     return testing.db.dialect.schemagenerator(testing.db.dialect,
         testing.db, None, None).get_column_specification(c)