Correct the parameter type used in function expressions.

Only using the non-default types doesn't provide access to the typehints
that were provided during the expression creation. This causes bound
parameters to be incorrect. While this change corrects the type of the bound
parameter it does not fix the selected value's type.

Refs #6739

src/Database/Expression/FunctionExpression.php

@@ -95,6 +95,7 @@ public function name($name = null)
     public function add($params, $types = [], $prepend = false)
     {
         $put = $prepend ? 'array_unshift' : 'array_push';
+        $typeMap = $this->typeMap()->types($types);
         foreach ($params as $k => $p) {
             if ($p === 'literal') {
                 $put($this->_conditions, $k);
@@ -105,9 +106,7 @@ public function add($params, $types = [], $prepend = false)
                 $put($this->_conditions, $p);
                 continue;
             }
-
-            $type = isset($types[$k]) ? $types[$k] : null;
-            $put($this->_conditions, ['value' => $p, 'type' => $type]);
+            $put($this->_conditions, ['value' => $p, 'type' => $typeMap->type($k)]);
         }
 
         return $this;

tests/TestCase/ORM/QueryRegressionTest.php

@@ -878,4 +878,30 @@ public function testFindLastOnEmptyTable()
         $this->assertEquals(0, $table->find()->count());
         $this->assertNull($table->find()->last());
     }
+
+    /**
+     * Test that the typemaps used in function expressions
+     * create the correct results.
+     *
+     * @return void
+     */
+    public function testTypemapInFunctions()
+    {
+        $table = TableRegistry::get('Comments');
+        $table->updateAll(['published' => null], ['1 = 1']);
+        $query = $table->find();
+        $query->select([
+            'id',
+            'coalesced' => $query->func()->coalesce(
+                ['published' => 'literal', -1],
+                ['integer']
+            )
+        ]);
+        $result = $query->all()->first();
+        $this->assertSame(
+            '-1',
+            $result['coalesced'],
+            'Output values for functions are not cast yet.'
+        );
+    }
 }

tests/TestCase/ORM/QueryTest.php

@@ -835,8 +835,7 @@ public function testApplyOptions()
 
         $this->assertEquals(1, $query->clause('limit'));
 
-        $expected = new QueryExpression(['a > b']);
-        $expected->typeMap($this->fooTypeMap);
+        $expected = new QueryExpression(['a > b'], $this->fooTypeMap);
         $result = $query->clause('join');
         $this->assertEquals([
             'table_a' => ['alias' => 'table_a', 'type' => 'INNER', 'conditions' => $expected]