Apply percent sign escaping to literal binds, comments

Fixed bug in new percent-sign support (e.g. :ticket:`3740`) where a bound
parameter rendered with literal_binds would fail to escape percent-signs
for relevant dialects.  In addition, ensured new table / column comment
support feature also fully makes use of literal-rendered parameters so that
this percent sign support takes place with table / column comment DDL as
well, allowing percent sign support for the mysql / psycopg2 backends that
require escaping of percent signs.

Change-Id: Ia4136a300933e9bc6a01a7b9afd5c7b9a3fee4e3
Fixes: #4054
Fixes: #4052

1 files changed, 18 insertions, 1 deletions

diff --git a/test/sql/test_text.py b/test/sql/test_text.py
index ca4d10702..c31c22853 100644
--- a/test/sql/test_text.py
+++ b/test/sql/test_text.py
@@ -4,7 +4,7 @@ from sqlalchemy.testing import fixtures, AssertsCompiledSQL, eq_, \
     assert_raises_message, expect_warnings, assert_warnings
 from sqlalchemy import text, select, Integer, String, Float, \
     bindparam, and_, func, literal_column, exc, MetaData, Table, Column,\
-    asc, func, desc, union
+    asc, func, desc, union, literal
 from sqlalchemy.types import NullType
 from sqlalchemy.sql import table, column, util as sql_util
 from sqlalchemy import util
@@ -331,6 +331,23 @@ class BindParamTest(fixtures.TestBase, AssertsCompiledSQL):
             dialect="mysql"
         )
 
+    def test_percent_signs_literal_binds(self):
+        stmt = select([literal("percent % signs %%")])
+        self.assert_compile(
+            stmt,
+            "SELECT 'percent % signs %%' AS anon_1",
+            dialect="sqlite",
+            literal_binds=True
+        )
+
+        self.assert_compile(
+            stmt,
+            "SELECT 'percent %% signs %%%%' AS anon_1",
+            dialect="mysql",
+            literal_binds=True
+        )
+
+
 class AsFromTest(fixtures.TestBase, AssertsCompiledSQL):
     __dialect__ = 'default'