[Sqlalchemy-tickets] Issue #4371: SQLAlchemy fails to ignores parameters that are inside of SQL Text comments in SQLAlchemy 1.2+? (zzzeek/sqlalchemy)

[cowbert <iss...@bi...>]

New issue 4371: SQLAlchemy fails to ignores parameters that are inside of SQL Text comments in SQLAlchemy 1.2+?
https://bitbucket.org/zzzeek/sqlalchemy/issues/4371/sqlalchemy-fails-to-ignores-parameters

cowbert:

Given a SQL textstring of:

```
#!python

s = sqlalchemy.sql.text("""With t as ( SELECT 'value1' v from dual union select 'value2' v 
    from dual)
    --, comment_cte as ("select 1 from dual")

        select * from t 
        --where t = :param_t
""")

```

In earlier versions of SQLAlchemy (1.1) and cx_Oracle (5.x), this can be executed by  SQLAlchemy core with:

    engine.connect().execute(s)

In SQLAlchemy 1.2+ and cxOracle 7, this will return an error reference to:  http://sqlalche.me/e/cd3x

SQLAlchemy properly ignores comments otherwise (for example, deleting the line `--where t = :param_t` will execute properly.)  Changing `--` style comments to the `/* */` style results in the same error.

Env: Python 3.6.4, SQLAlchemy 1.2.14, cx-Oracle 7.0.0

Full stack trace:

```
#!python

Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1127, in _execute_context
    context = constructor(dialect, self, conn, *args)
  File "/usr/lib/python3.6/site-packages/sqlalchemy/engine/default.py", line 631, in _init_compiled
    self.compiled_parameters = [compiled.construct_params()]
  File "/usr/lib/python3.6/site-packages/sqlalchemy/sql/compiler.py", line 566, in construct_params
    % bindparam.key, code="cd3x")
sqlalchemy.exc.InvalidRequestError: A value is required for bind parameter 'param_t' (Background on this error at: http://sqlalche.me/e/cd3x)

```