Make boolean processors consistent between Py/C; coerce to 1/0

The processing performed by the :class:`.Boolean` datatype for backends
that only feature integer types has been made consistent between the
pure Python and C-extension versions, in that the C-extension version
will accept any integer value from the database as a boolean, not just
zero and one; additionally, non-boolean integer values being sent to
the database are coerced to exactly zero or one, instead of being
passed as the original integer value.

Change-Id: I01e647547fd7047bd549dd70e1fa202c51e8328b
Fixes: #3730

2 files changed, 4 insertions, 14 deletions

diff --git a/lib/sqlalchemy/cextension/processors.c b/lib/sqlalchemy/cextension/processors.c
index 5357e34dc..5b7527c20 100644
--- a/lib/sqlalchemy/cextension/processors.c
+++ b/lib/sqlalchemy/cextension/processors.c
@@ -22,28 +22,18 @@ typedef int Py_ssize_t;
 static PyObject *
 int_to_boolean(PyObject *self, PyObject *arg)
 {
-    long l = 0;
+    int l = 0;
     PyObject *res;
 
     if (arg == Py_None)
         Py_RETURN_NONE;
 
-
-#if PY_MAJOR_VERSION >= 3
-    l = PyLong_AsLong(arg);
-#else
-    l = PyInt_AsLong(arg);
-#endif
+    l = PyObject_IsTrue(arg);
     if (l == 0) {
         res = Py_False;
     } else if (l == 1) {
         res = Py_True;
-    } else if ((l == -1) && PyErr_Occurred()) {
-        /* -1 can be either the actual value, or an error flag. */
-        return NULL;
     } else {
-        PyErr_SetString(PyExc_ValueError,
-                        "int_to_boolean only accepts None, 0 or 1");
         return NULL;
     }
 
diff --git a/lib/sqlalchemy/processors.py b/lib/sqlalchemy/processors.py
index b57e6740b..98f8a2759 100644
--- a/lib/sqlalchemy/processors.py
+++ b/lib/sqlalchemy/processors.py
@@ -53,7 +53,7 @@ def boolean_to_int(value):
     if value is None:
         return None
     else:
-        return int(value)
+        return int(bool(value))
 
 
 def py_fallback():
@@ -111,7 +111,7 @@ def py_fallback():
         if value is None:
             return None
         else:
-            return value and True or False
+            return bool(value)
 
     DATETIME_RE = re.compile(
         "(\d+)-(\d+)-(\d+) (\d+):(\d+):(\d+)(?:\.(\d+))?")