From 7380087176c6613832e2f5b4d35c6aeeea373dd1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=BCnter=20Obiltschnig?= <guenter.obiltschnig@appinf.com>
Date: Fri, 27 Nov 2020 19:32:00 +0100
Subject: [PATCH] #3153: Poco::Data::ODBC [N]VARCHAR(MAX) wrong maxDataSize()
 result

---
 Data/ODBC/src/Preparator.cpp | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/Data/ODBC/src/Preparator.cpp b/Data/ODBC/src/Preparator.cpp
index 1b00eca2a..fa4f91f16 100644
--- a/Data/ODBC/src/Preparator.cpp
+++ b/Data/ODBC/src/Preparator.cpp
@@ -25,10 +25,10 @@ namespace Data {
 namespace ODBC {
 
 
-Preparator::Preparator(const StatementHandle& rStmt, 
-	const std::string& statement, 
+Preparator::Preparator(const StatementHandle& rStmt,
+	const std::string& statement,
 	std::size_t maxFieldSize,
-	DataExtraction dataExtraction): 
+	DataExtraction dataExtraction):
 	_rStmt(rStmt),
 	_maxFieldSize(maxFieldSize),
 	_dataExtraction(dataExtraction)
@@ -39,7 +39,7 @@ Preparator::Preparator(const StatementHandle& rStmt,
 }
 
 
-Preparator::Preparator(const Preparator& other): 
+Preparator::Preparator(const Preparator& other):
 	_rStmt(other._rStmt),
 	_maxFieldSize(other._maxFieldSize),
 	_dataExtraction(other._dataExtraction)
@@ -151,14 +151,14 @@ std::size_t Preparator::maxDataSize(std::size_t pos) const
 	std::size_t sz = 0;
 	std::size_t maxsz = getMaxFieldSize();
 
-	try 
+	try
 	{
 		ODBCMetaColumn mc(_rStmt, pos);
 		sz = mc.length();
 
 		// accomodate for terminating zero (non-bulk only!)
 		MetaColumn::ColumnDataType type = mc.type();
-		if (!isBulk() && ((ODBCMetaColumn::FDT_WSTRING == type) || (ODBCMetaColumn::FDT_STRING == type))) ++sz;
+		if (sz && !isBulk() && ((ODBCMetaColumn::FDT_WSTRING == type) || (ODBCMetaColumn::FDT_STRING == type))) ++sz;
 	}
 	catch (StatementException&) { }
 
@@ -194,11 +194,11 @@ void Preparator::prepareBoolArray(std::size_t pos, SQLSMALLINT valueType, std::s
 	_lenLengths[pos].resize(length);
 	_varLengthArrays.insert(IndexMap::value_type(pos, DT_BOOL_ARRAY));
 
-	if (Utility::isError(SQLBindCol(_rStmt, 
-		(SQLUSMALLINT) pos + 1, 
-		valueType, 
-		(SQLPOINTER) pArray, 
-		(SQLINTEGER) sizeof(bool), 
+	if (Utility::isError(SQLBindCol(_rStmt,
+		(SQLUSMALLINT) pos + 1,
+		valueType,
+		(SQLPOINTER) pArray,
+		(SQLINTEGER) sizeof(bool),
 		&_lenLengths[pos][0])))
 	{
 		throw StatementException(_rStmt, "SQLBindCol()");