Index: src/vdbeaux.c
==================================================================
--- src/vdbeaux.c
+++ src/vdbeaux.c
@@ -2158,21 +2158,22 @@
 ** statement. This is now set at compile time, rather than during
 ** execution of the vdbe program so that sqlite3_column_count() can
 ** be called on an SQL statement before sqlite3_step().
 */
 void sqlite3VdbeSetNumCols(Vdbe *p, int nResColumn){
-  Mem *pColName;
   int n;
   sqlite3 *db = p->db;
 
-  releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
-  sqlite3DbFree(db, p->aColName);
+  if( p->nResColumn ){
+    releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
+    sqlite3DbFree(db, p->aColName);
+  }
   n = nResColumn*COLNAME_N;
   p->nResColumn = (u16)nResColumn;
-  p->aColName = pColName = (Mem*)sqlite3DbMallocRawNN(db, sizeof(Mem)*n );
+  p->aColName = (Mem*)sqlite3DbMallocRawNN(db, sizeof(Mem)*n );
   if( p->aColName==0 ) return;
-  initMemArray(p->aColName, n, p->db, MEM_Null);
+  initMemArray(p->aColName, n, db, MEM_Null);
 }
 
 /*
 ** Set the name of the idx'th column to be returned by the SQL statement.
 ** zName must be a pointer to a nul terminated string.