An extra null row is returned if rowset size is a multiple of row cache size

Hi,
 The odbc driver is returning an extra null filled row when the number of rows
to be retrieved is a multiple of the row cache size set in the odbc driver. If
this occurs when issuing a SQLColumns or SQLtables request, the driver will
return an error trying to convert the null filled row into column or table row
values.
 In normal usage, my smalltalk based app, can abend because the final row
returned has nulls in columns that cannot possibly be null.

 I have had a look at the current cvs source, and cannot determine where the
problem is (I am not a c progremmer - but can maintain c (with difficulty and
under protest  :).)

This is a serious problem for us which we are hitting fairly often and need to
fix real soon. I am continuing to read the odbc driver code - but any pointers
for what to try/where to look  would be real usefull.


My odbc settings are :-
Recognize unique indexes,
Use Declare fetch
Parse statements
Unknown sizes - longest
Text a long varchar
unknown as long varchar
bools as char
cache size 25
updateable cursors
dissalow premature.

Here is the bit of the odbc log where it goes wrong (I think).
This is retrieving 50 rows with a cache size of 25.

[848]next_tuple: fetch_count < fcount: returning tuple 24, fcount = 25
[848]fetch: cols=6, lf=0, opts = 68763272, opts->bindings = 68751064, buffer[]
= 1658672
[848]type = 23
[848]value = '0'
[848]copy_and_convert: field_type = 23, fctype = 4, value = '0', cbValueMax=4
[848]copy_and_convert: retval = 0
[848]fetch: cols=6, lf=1, opts = 68763272, opts->bindings = 68751064, buffer[]
= 1658680
[848]type = 1043
[848]value = 'WB-OST'
[848]copy_and_convert: field_type = 1043, fctype = 1, value = 'WB-OST',
cbValueMax=16
[848]DEFAULT: len = 6, ptr = 'WB-OST'
[848]    SQL_C_CHAR, default: len = 6, cbValueMax = 16, rgbValueBindRow =
'WB-OST'
[848]copy_and_convert: retval = 0
[848]fetch: cols=6, lf=2, opts = 68763272, opts->bindings = 68751064, buffer[]
= 1658700
[848]type = 1043
[848]value = 'WHEEL'
[848]copy_and_convert: field_type = 1043, fctype = 1, value = 'WHEEL',
cbValueMax=16
[848]DEFAULT: len = 5, ptr = 'WHEEL'
[848]    SQL_C_CHAR, default: len = 5, cbValueMax = 16, rgbValueBindRow =
'WHEEL'
[848]copy_and_convert: retval = 0
[848]fetch: cols=6, lf=3, opts = 68763272, opts->bindings = 68751064, buffer[]
= 1658720
[848]type = 1043
[848]value = 'Wheel Bearing Repack - O/S/T'
[848]copy_and_convert: field_type = 1043, fctype = 1, value = 'Wheel Bearing
Repack - O/S/T', cbValueMax=31
[848]DEFAULT: len = 28, ptr = 'Wheel Bearing Repack - O/S/T'
[848]    SQL_C_CHAR, default: len = 28, cbValueMax = 31, rgbValueBindRow =
'Wheel Bearing Repack - O/S/T'
[848]copy_and_convert: retval = 0
[848]fetch: cols=6, lf=4, opts = 68763272, opts->bindings = 68751064, buffer[]
= 1658755
[848]type = 1043
[848]value = 'No'
[848]copy_and_convert: field_type = 1043, fctype = 1, value = 'No',
cbValueMax=11
[848]DEFAULT: len = 2, ptr = 'No'
[848]    SQL_C_CHAR, default: len = 2, cbValueMax = 11, rgbValueBindRow = 'No'
[848]copy_and_convert: retval = 0
[848]fetch: cols=6, lf=5, opts = 68763272, opts->bindings = 68751064, buffer[]
= 1658770
[848]type = 1043
[848]value = 'Service'
[848]copy_and_convert: field_type = 1043, fctype = 1, value = 'Service',
cbValueMax=16
[848]DEFAULT: len = 7, ptr = 'Service'
[848]    SQL_C_CHAR, default: len = 7, cbValueMax = 16, rgbValueBindRow =
'Service'
[848]copy_and_convert: retval = 0
[848][SQLExtendedFetch][848]PGAPI_ExtendedFetch: stmt=68763192
[848]SQL_FETCH_NEXT: num_tuples=50, currtuple=25
[848]PGAPI_ExtendedFetch: new currTuple = 49
[848]manual_result = 0, use_declarefetch = 1
[848]clear obsolete 25 tuples
[848]next_tuple: sending actual fetch (25) query 'fetch 25 in SQL_CUR04193E38'
[848]send_query(): conn=18913808, query='fetch 25 in SQL_CUR04193E38'
[848]send_query: done sending query
[848]send_query: got id = 'Z'
[848]read 175, global_socket_buffersize=4096
[848]send_query: got id = 'P'
[848]send_query: got id = 'T'
[848]num_fields = 6
[848]READING ATTTYPMOD
[848]CI_read_fields: fieldname='company_id', adtid=23, adtsize=4, atttypmod=-1
[848]READING ATTTYPMOD
[848]CI_read_fields: fieldname='service_code', adtid=1043, adtsize=-1,
atttypmod=15
[848]READING ATTTYPMOD
[848]CI_read_fields: fieldname='service_type_code', adtid=1043, adtsize=-1,
atttypmod=15
[848]READING ATTTYPMOD
[848]CI_read_fields: fieldname='service_desc', adtid=1043, adtsize=-1,
atttypmod=30
[848]READING ATTTYPMOD
[848]CI_read_fields: fieldname='print_jobcard', adtid=1043, adtsize=-1,
atttypmod=10
[848]READING ATTTYPMOD
[848]CI_read_fields: fieldname='sheet_type_flag', adtid=1043, adtsize=-1,
atttypmod=15
[848]end of tuple list -- setting inUse to false: this = 18913232
[848]_next_tuple: 'C' fetch_max && fcount = 50
[848]fetch: cols=6, lf=0, opts = 68763272, opts->bindings = 68751064, buffer[]
= 1658672
[848]type = 23
[848]value = '<NULL>'
[848]copy_and_convert: field_type = 23, fctype = 4, value = '<NULL>',
cbValueMax=4
[848]copy_and_convert: retval = 0
[848]fetch: cols=6, lf=1, opts = 68763272, opts->bindings = 68751064, buffer[]
= 1658680
[848]type = 1043
[848]value = '<NULL>'
[848]copy_and_convert: field_type = 1043, fctype = 1, value = '<NULL>',
cbValueMax=16
[848]copy_and_convert: retval = 0
[848]fetch: cols=6, lf=2, opts = 68763272, opts->bindings = 68751064, buffer[]
= 1658700
[848]type = 1043
[848]value = '<NULL>'
[848]copy_and_convert: field_type = 1043, fctype = 1, value = '<NULL>',
cbValueMax=16
[848]copy_and_convert: retval = 0
[848]fetch: cols=6, lf=3, opts = 68763272, opts->bindings = 68751064, buffer[]
= 1658720
[848]type = 1043
[848]value = '<NULL>'
[848]copy_and_convert: field_type = 1043, fctype = 1, value = '<NULL>',
cbValueMax=31
[848]copy_and_convert: retval = 0
[848]fetch: cols=6, lf=4, opts = 68763272, opts->bindings = 68751064, buffer[]
= 1658755
[848]type = 1043
[848]value = '<NULL>'
[848]copy_and_convert: field_type = 1043, fctype = 1, value = '<NULL>',
cbValueMax=11
[848]copy_and_convert: retval = 0
[848]fetch: cols=6, lf=5, opts = 68763272, opts->bindings = 68751064, buffer[]
= 1658770
[848]type = 1043
[848]value = '<NULL>'
[848]copy_and_convert: field_type = 1043, fctype = 1, value = '<NULL>',
cbValueMax=16
[848]copy_and_convert: retval = 0
[848]manual_result = 0, use_declarefetch = 1
[848]next_tuple: fcount < CACHE_SIZE: fcount = 0, fetch_count = 1
[848]**** SC_fetch: end_tuples
[848][SQLExtendedFetch][848]PGAPI_ExtendedFetch: stmt=68763192
[848]SQL_FETCH_NEXT: num_tuples=50, currtuple=50
[848][SQLFreeStmt][848]PGAPI_FreeStmt: entering...hstmt=68763192, fOption=0



Regards,
Wayne Armstrong
Bacchus Management Systems
http://www.bacchus.com.au