Added new test cases for Issue 1310 (#1321)

test/functional/pdo_sqlsrv/pdo_1310_null_varchar.phpt

@@ -0,0 +1,88 @@
+--TEST--
+GitHub issue 1310 - bind null field as varchar(max) if not binary
+--DESCRIPTION--
+The test shows null fields are no longer bound as char(1) if not binary such that it solves both issues 1310 and 1102.
+--ENV--
+PHPT_EXEC=true
+--SKIPIF--
+<?php require('skipif.inc'); ?>
+--FILE--
+<?php
+require_once("MsSetup.inc");
+require_once("MsCommon_mid-refactor.inc");
+
+try {
+    $conn = connect();
+    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+
+    // Issue 1310
+    $query = "SELECT CAST(ISNULL(:K, -1) AS INT) AS K";
+    $k = null;
+
+    $stmt = $conn->prepare($query);
+    $stmt->bindParam(':K', $k, PDO::PARAM_NULL);
+    $stmt->execute();
+
+    $row = $stmt->fetchAll(PDO::FETCH_ASSOC);
+    var_dump($row);
+
+    $stmt->bindParam(':K', $k, PDO::PARAM_INT);
+    $stmt->execute();
+
+    $row = $stmt->fetchAll(PDO::FETCH_NUM);
+    var_dump($row);
+
+    // Issue 1102
+    $query = "DECLARE @d DATETIME = ISNULL(:K, GETDATE()); SELECT @d AS D;";
+    $k = null;
+
+    $stmt = $conn->prepare($query);
+    $stmt->bindParam(':K', $k, PDO::PARAM_NULL);
+    $stmt->execute();
+
+    $row = $stmt->fetchAll(PDO::FETCH_NUM);
+    var_dump($row);
+
+    $stmt->bindParam(':K', $k, PDO::PARAM_INT);
+    $stmt->execute();
+
+    $row = $stmt->fetchAll(PDO::FETCH_ASSOC);
+    var_dump($row);
+
+    echo "Done\n";
+} catch (PdoException $e) {
+    echo $e->getMessage();
+}
+
+?>
+--EXPECTREGEX--
+array\(1\) {
+  \[0\]=>
+  array\(1\) {
+    \["K"\]=>
+    string\(2\) "-1"
+  }
+}
+array\(1\) {
+  \[0\]=>
+  array\(1\) {
+    \[0\]=>
+    string\(2\) "-1"
+  }
+}
+array\(1\) {
+  \[0\]=>
+  array\(1\) {
+    \[0\]=>
+    string\(23\) "20[0-9]{2}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:00.000"
+  }
+}
+array\(1\) {
+  \[0\]=>
+  array\(1\) {
+    \["D"\]=>
+    string\(23\) "20[0-9]{2}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:00.000"
+  }
+}
+Done
+

test/functional/sqlsrv/srv_1310_null_varchar.phpt

@@ -0,0 +1,64 @@
+--TEST--
+GitHub issue 1310 - bind null field as varchar(max) if not binary
+--DESCRIPTION--
+The test shows null fields are no longer bound as char(1) if not binary such that it solves both issues 1310 and 1102.
+--ENV--
+PHPT_EXEC=true
+--SKIPIF--
+<?php require('skipif_versions_old.inc'); ?>
+--FILE--
+<?php
+require_once('MsCommon.inc');
+
+$conn = AE\connect();
+
+// Issue 1310
+$query = "SELECT CAST(ISNULL(?, -1) AS INT) AS K";
+$k = null;
+$params = array($k);
+
+$stmt = sqlsrv_prepare($conn, $query, $params);
+if (!$stmt) {
+    fatalError("Failed to prepare statement (1).");
+}
+if (!sqlsrv_execute($stmt)) {
+    fatalError("Failed to execute query (1).");
+}
+
+while ($row = sqlsrv_fetch_array($stmt, SQLSRV_FETCH_ASSOC)) {
+    var_dump($row);
+}
+
+sqlsrv_free_stmt($stmt);
+
+// Issue 1102
+$query = "DECLARE @d DATETIME = ISNULL(?, GETDATE()); SELECT @d AS D;";
+$k = null;
+$params = array($k, null, null, null);
+
+$options = array('ReturnDatesAsStrings'=> true);
+$stmt = sqlsrv_query($conn, $query, $params, $options);
+if (!$stmt) {
+    fatalError("Failed to query statement (2).");
+}
+
+while ($row = sqlsrv_fetch_array($stmt, SQLSRV_FETCH_ASSOC)) {
+    var_dump($row);
+}
+
+sqlsrv_free_stmt($stmt);
+sqlsrv_close($conn);
+
+echo "Done\n";
+
+?>
+--EXPECTREGEX--
+array\(1\) {
+  \["K"\]=>
+  int\(-1\)
+}
+array\(1\) {
+  \["D"\]=>
+  string\(23\) "20[0-9]{2}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:00.000"
+}
+Done