Commented by: Jojakim Stahl (jstahl)

The problem was, that binding->startedTransfer flag was not set, when SQLPutData has been called with SQL_NEED_DATA.
I changed it now this way, that also for SQL_NULL_DATA the standard field setter routine is sqlPutData is used. This sets SQL_NULL_DATA for the appDescriptor and the impDescriptor.
I removed the setNull function from DescRecord class becaus it was used only in sqlPutData and seems to be dangerous. It sets a *(short*) value. When my research is right, this is only correct if the DescRecord is used for the implementationParamDescriptor. The applicationParamDescriptor should set *indicatorPtr without cast, because ODBC uses SQLLEN. Should one call setNull for the application side, the value will not be correct (high-word not modified).
I think, that this fix also solves the ticket #⁠ODBC134 but I could not test this in the short time frame I had.

--- e:\http://OdbcFb.org/DescRecord.h 2010-10-24 12:27:15.000000000 +0200
+++ ./DescRecord.h 2012-05-24 12:05:55.296222200 +0200
@@ -47,12 +47,6 @@
void putBlobSegmentData (int length, const void *bytes);
void endBlobDataTransfer();

- void setNull()
- {
- if ( indicatorPtr )
- *(short*)indicatorPtr = -1;
- }
-
int getBufferLength()
{
return ( octetLength + 1 ) * headSqlVarPtr->getSqlMultiple();
--- e:\http://OdbcFb.org/OdbcStatement.cpp 2012-03-01 11:33:55.000000000 +0100
+++ ./OdbcStatement.cpp 2012-05-24 14:14:04.793788400 +0200
@@ -3108,12 +3106,7 @@

DescRecord \*binding = applicationParamDescriptor\-\>getDescRecord \(parameterNeedData\);

- if (valueSize == SQL_NULL_DATA)
- {
- binding->setNull();
- *binding->indicatorPtr = SQL_NULL_DATA;
- }
- else if ( binding->isBlobOrArray )
+ if ( valueSize != SQL_NULL_DATA && binding->isBlobOrArray )
{
if ( !binding->startedTransfer )
binding->beginBlobDataTransfer();

Commented by: @alexpotapchenko

fixed in CVS