Have the sqlite3_context object carry the encoding for the prepared statement

that it represents, so that sqlite3_result() and similar can set the encoding
according to the prepared statement, even if the database encoding has
changed.
dbsqlfuzz c409b10d0a6bccf78ab00f47e1d29d42ee5b3565

FossilOrigin-Name: d4e19314f564126e180e091f9135c7bc55a10442edb46fbd3a4cfad21201dfa6

4 files changed, 9 insertions, 2 deletions

diff --git a/src/vdbe.c b/src/vdbe.c
index ec227f884..138210943 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -7249,6 +7249,7 @@ case OP_AggStep: {
   pCtx->pVdbe = p;
   pCtx->skipFlag = 0;
   pCtx->isError = 0;
+  pCtx->enc = encoding;
   pCtx->argc = n;
   pOp->p4type = P4_FUNCCTX;
   pOp->p4.pCtx = pCtx;
@@ -7898,6 +7899,7 @@ case OP_VColumn: {
   assert( pModule->xColumn );
   memset(&sContext, 0, sizeof(sContext));
   sContext.pOut = pDest;
+  sContext.enc = encoding;
   assert( pOp->p5==OPFLAG_NOCHNG || pOp->p5==0 );
   if( pOp->p5 & OPFLAG_NOCHNG ){
     sqlite3VdbeMemSetNull(pDest);
@@ -8182,6 +8184,7 @@ case OP_Function: {            /* group */
   if( pCtx->pOut != pOut ){
     pCtx->pVdbe = p;
     pCtx->pOut = pOut;
+    pCtx->enc = encoding;
     for(i=pCtx->argc-1; i>=0; i--) pCtx->argv[i] = &aMem[pOp->p2+i];
   }
   assert( pCtx->pVdbe==p );
diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index 45720b6a5..32c341eb8 100644
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -369,6 +369,7 @@ struct sqlite3_context {
   Vdbe *pVdbe;            /* The VM that owns this context */
   int iOp;                /* Instruction number of OP_Function */
   int isError;            /* Error code returned by the function. */
+  u8 enc;                 /* Encoding to use for results */
   u8 skipFlag;            /* Skip accumulator loading if true */
   u8 argc;                /* Number of arguments */
   sqlite3_value *argv[1]; /* Argument set */
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index 7567b8994..c23dd0e0c 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -391,7 +391,7 @@ static void setResultStrOrError(
     }
     return;
   }
-  sqlite3VdbeChangeEncoding(pOut, ENC(pOut->db));
+  sqlite3VdbeChangeEncoding(pOut, pCtx->enc);
   if( sqlite3VdbeMemTooBig(pOut) ){
     sqlite3_result_error_toobig(pCtx);
   }
@@ -540,7 +540,7 @@ void sqlite3_result_value(sqlite3_context *pCtx, sqlite3_value *pValue){
   Mem *pOut = pCtx->pOut;
   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   sqlite3VdbeMemCopy(pOut, pValue);
-  sqlite3VdbeChangeEncoding(pOut, ENC(pOut->db));
+  sqlite3VdbeChangeEncoding(pOut, pCtx->enc);
   if( sqlite3VdbeMemTooBig(pOut) ){
     sqlite3_result_error_toobig(pCtx);
   }
diff --git a/src/vdbemem.c b/src/vdbemem.c
index 82d79a580..5eac7cf71 100644
--- a/src/vdbemem.c
+++ b/src/vdbemem.c
@@ -467,6 +467,7 @@ int sqlite3VdbeMemFinalize(Mem *pMem, FuncDef *pFunc){
   ctx.pOut = &t;
   ctx.pMem = pMem;
   ctx.pFunc = pFunc;
+  ctx.enc = ENC(t.db);
   pFunc->xFinalize(&ctx); /* IMP: R-24505-23230 */
   assert( (pMem->flags & MEM_Dyn)==0 );
   if( pMem->szMalloc>0 ) sqlite3DbFreeNN(pMem->db, pMem->zMalloc);
@@ -494,6 +495,7 @@ int sqlite3VdbeMemAggValue(Mem *pAccum, Mem *pOut, FuncDef *pFunc){
   ctx.pOut = pOut;
   ctx.pMem = pAccum;
   ctx.pFunc = pFunc;
+  ctx.enc = ENC(pAccum->db);
   pFunc->xValue(&ctx);
   return ctx.isError;
 }
@@ -1491,6 +1493,7 @@ static int valueFromFunction(
   memset(&ctx, 0, sizeof(ctx));
   ctx.pOut = pVal;
   ctx.pFunc = pFunc;
+  ctx.enc = ENC(db);
   pFunc->xSFunc(&ctx, nVal, apVal);
   if( ctx.isError ){
     rc = ctx.isError;