- Fix wrong error "Invalid offset for CVS table" when a special

  column is defined in a CSV table (MDEV-6187)
modified:
  storage/connect/ha_connect.cc
  storage/connect/reldef.h
  storage/connect/tabfmt.cpp

storage/connect/ha_connect.cc

@@ -2708,7 +2708,6 @@ int ha_connect::index_next_same(uchar *buf, const uchar *key, uint keylen)
 */
 int ha_connect::rnd_init(bool scan)
 {
-  int     rc;
   PGLOBAL g= ((table && table->in_use) ? GetPlug(table->in_use, xp) :
               (xp) ? xp->g : NULL);
   DBUG_ENTER("ha_connect::rnd_init");
@@ -2742,8 +2741,8 @@ int ha_connect::rnd_init(bool scan)
   if (xmod == MODE_UPDATE)
     bitmap_union(table->read_set, table->write_set);
 
-  if ((rc= OpenTable(g, xmod == MODE_DELETE)))
-    DBUG_RETURN(rc);
+  if (OpenTable(g, xmod == MODE_DELETE))
+    DBUG_RETURN(HA_ERR_INITIALIZATION);
 
   xp->nrd= xp->fnd= xp->nfd= 0;
   xp->tb1= my_interval_timer();

storage/connect/reldef.h

@@ -195,6 +195,7 @@ class DllExport COLDEF : public COLCRT { /* Column description block
   int     GetPoff(void) {return Poff;}
   int     Define(PGLOBAL g, void *memp, PCOLINFO cfp, int poff);
   void    Define(PGLOBAL g, PCOL colp);
+  bool    IsSpecial(void) {return (Flags & U_SPECIAL) ? true : false;} 
 
  protected:
   int     Buf_Type;            /* Internal data type                   */

storage/connect/tabfmt.cpp

@@ -406,7 +406,7 @@ bool CSVDEF::DefineAM(PGLOBAL g, LPCSTR am, int poff)
   // Double check correctness of offset values
   if (Catfunc == FNC_NO)
     for (PCOLDEF cdp = To_Cols; cdp; cdp = cdp->GetNext())
-      if (cdp->GetOffset() < 1) {
+      if (cdp->GetOffset() < 1 && !cdp->IsSpecial()) {
         strcpy(g->Message, MSG(BAD_OFFSET_VAL));
         return true;
         } // endif Offset