Index: src/sqlite.h.in
==================================================================
--- src/sqlite.h.in
+++ src/sqlite.h.in
@@ -4761,14 +4761,15 @@
 ** metadata associated with the pattern string.  
 ** Then as long as the pattern string remains the same,
 ** the compiled regular expression can be reused on multiple
 ** invocations of the same function.
 **
-** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
-** associated by the sqlite3_set_auxdata() function with the Nth argument
-** value to the application-defined function. ^If there is no metadata
-** associated with the function argument, this sqlite3_get_auxdata() interface
+** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
+** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
+** value to the application-defined function.  ^N is zero for the left-most
+** function argument.  ^If there is no metadata
+** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
 ** returns a NULL pointer.
 **
 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
 ** argument of the application-defined function.  ^Subsequent
 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
@@ -4794,10 +4795,14 @@
 ** sqlite3_set_auxdata() has been called.
 **
 ** ^(In practice, metadata is preserved between function calls for
 ** function parameters that are compile-time constants, including literal
 ** values and [parameters] and expressions composed from the same.)^
+**
+** The value of the N parameter to these interfaces should be non-negative.
+** Future enhancements may make use of negative N values to define new
+** kinds of function caching behavior.
 **
 ** These routines must be called from the same thread in which
 ** the SQL function is running.
 */
 void *sqlite3_get_auxdata(sqlite3_context*, int N);

Index: src/vdbeapi.c
==================================================================
--- src/vdbeapi.c
+++ src/vdbeapi.c
@@ -802,10 +802,16 @@
 }
 
 /*
 ** Return the auxiliary data pointer, if any, for the iArg'th argument to
 ** the user-function defined by pCtx.
+**
+** The left-most argument is 0.
+**
+** Undocumented behavior:  If iArg is negative then access a cache of
+** auxiliary data pointers that is available to all functions within a
+** single prepared statement.  The iArg values must match.
 */
 void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){
   AuxData *pAuxData;
 
   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
@@ -813,11 +819,11 @@
   if( pCtx->pVdbe==0 ) return 0;
 #else
   assert( pCtx->pVdbe!=0 );
 #endif
   for(pAuxData=pCtx->pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){
-    if( pAuxData->iAuxOp==pCtx->iOp && pAuxData->iAuxArg==iArg ){
+    if(  pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){
       return pAuxData->pAux;
     }
   }
   return 0;
 }
@@ -824,10 +830,16 @@
 
 /*
 ** Set the auxiliary data pointer and delete function, for the iArg'th
 ** argument to the user-function defined by pCtx. Any previous value is
 ** deleted by calling the delete function specified when it was set.
+**
+** The left-most argument is 0.
+**
+** Undocumented behavior:  If iArg is negative then make the data available
+** to all functions within the current prepared statement using iArg as an
+** access code.
 */
 void sqlite3_set_auxdata(
   sqlite3_context *pCtx, 
   int iArg, 
   void *pAux, 
@@ -835,19 +847,20 @@
 ){
   AuxData *pAuxData;
   Vdbe *pVdbe = pCtx->pVdbe;
 
   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
-  if( iArg<0 ) goto failed;
 #ifdef SQLITE_ENABLE_STAT3_OR_STAT4
   if( pVdbe==0 ) goto failed;
 #else
   assert( pVdbe!=0 );
 #endif
 
   for(pAuxData=pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){
-    if( pAuxData->iAuxOp==pCtx->iOp && pAuxData->iAuxArg==iArg ) break;
+    if( pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){
+      break;
+    }
   }
   if( pAuxData==0 ){
     pAuxData = sqlite3DbMallocZero(pVdbe->db, sizeof(AuxData));
     if( !pAuxData ) goto failed;
     pAuxData->iAuxOp = pCtx->iOp;

Index: src/vdbeaux.c
==================================================================
--- src/vdbeaux.c
+++ src/vdbeaux.c
@@ -2966,11 +2966,12 @@
 */
 void sqlite3VdbeDeleteAuxData(sqlite3 *db, AuxData **pp, int iOp, int mask){
   while( *pp ){
     AuxData *pAux = *pp;
     if( (iOp<0)
-     || (pAux->iAuxOp==iOp 
+     || (pAux->iAuxOp==iOp
+          && pAux->iAuxArg>=0
           && (pAux->iAuxArg>31 || !(mask & MASKBIT32(pAux->iAuxArg))))
     ){
       testcase( pAux->iAuxArg==31 );
       if( pAux->xDeleteAux ){
         pAux->xDeleteAux(pAux->pAux);