Was because of buffer overrun in XCLCOL::ReadColumn.
  The Cbuf buffer was unconditionally filled Now it is limited to its size.
  This happened because this buffer was allocated according to the XCOL
  column size. It is now allocated according to the source column size.
modified:
  storage/connect/plgdbsem.h
  storage/connect/tabutil.h
  storage/connect/tabxcl.cpp
  storage/connect/tabxcl.h