Index: src/mem2.c
==================================================================
--- src/mem2.c
+++ src/mem2.c
@@ -376,11 +376,11 @@
 
 /*
 ** Set the "type" of an allocation.
 */
 void sqlite3MemdebugSetType(void *p, u8 eType){
-  if( p ){
+  if( p && sqlite3GlobalConfig.m.xMalloc==sqlite3MemMalloc ){
     struct MemBlockHdr *pHdr;
     pHdr = sqlite3MemsysGetHeader(p);
     assert( pHdr->iForeGuard==FOREGUARD );
     pHdr->eType = eType;
   }
@@ -395,11 +395,11 @@
 **
 **     assert( sqlite3MemdebugHasType(p, MEMTYPE_DB) );
 */
 int sqlite3MemdebugHasType(void *p, u8 eType){
   int rc = 1;
-  if( p ){
+  if( p && sqlite3GlobalConfig.m.xMalloc==sqlite3MemMalloc ){
     struct MemBlockHdr *pHdr;
     pHdr = sqlite3MemsysGetHeader(p);
     assert( pHdr->iForeGuard==FOREGUARD );         /* Allocation is valid */
     if( (pHdr->eType&eType)==0 ){
       rc = 0;
@@ -417,11 +417,11 @@
 **
 **     assert( sqlite3MemdebugNoType(p, MEMTYPE_DB) );
 */
 int sqlite3MemdebugNoType(void *p, u8 eType){
   int rc = 1;
-  if( p ){
+  if( p && sqlite3GlobalConfig.m.xMalloc==sqlite3MemMalloc ){
     struct MemBlockHdr *pHdr;
     pHdr = sqlite3MemsysGetHeader(p);
     assert( pHdr->iForeGuard==FOREGUARD );         /* Allocation is valid */
     if( (pHdr->eType&eType)!=0 ){
       rc = 0;