Index: src/vdbeapi.c
==================================================================
--- src/vdbeapi.c
+++ src/vdbeapi.c
@@ -255,12 +255,12 @@
 ** Allocate or return the aggregate context for a user function.  A new
 ** context is allocated on the first call.  Subsequent calls return the
 ** same context that was returned on prior calls.
 */
 void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
-  assert( p && p->pFunc && p->pFunc->xStep );
   Mem *pMem = p->pMem;
+  assert( p && p->pFunc && p->pFunc->xStep );
   if( (pMem->flags & MEM_Agg)==0 ){
     if( nByte==0 ){
       assert( pMem->flags==MEM_Null );
       pMem->z = 0;
     }else{