Index: src/vdbe.c
==================================================================
--- src/vdbe.c
+++ src/vdbe.c
@@ -1918,15 +1918,19 @@
     }else if( affinity==SQLITE_AFF_TEXT ){
       if( (pIn1->flags & MEM_Str)==0 && (pIn1->flags & (MEM_Int|MEM_Real))!=0 ){
         testcase( pIn1->flags & MEM_Int );
         testcase( pIn1->flags & MEM_Real );
         sqlite3VdbeMemStringify(pIn1, encoding, 1);
+        testcase( (flags1&MEM_Dyn) != (pIn1->flags&MEM_Dyn) );
+        flags1 = (pIn1->flags & ~MEM_TypeMask) | (flags1 & MEM_TypeMask);
       }
       if( (pIn3->flags & MEM_Str)==0 && (pIn3->flags & (MEM_Int|MEM_Real))!=0 ){
         testcase( pIn3->flags & MEM_Int );
         testcase( pIn3->flags & MEM_Real );
         sqlite3VdbeMemStringify(pIn3, encoding, 1);
+        testcase( (flags3&MEM_Dyn) != (pIn3->flags&MEM_Dyn) );
+        flags3 = (pIn3->flags & ~MEM_TypeMask) | (flags3 & MEM_TypeMask);
       }
     }
     assert( pOp->p4type==P4_COLLSEQ || pOp->p4.pColl==0 );
     if( pIn1->flags & MEM_Zero ){
       sqlite3VdbeMemExpandBlob(pIn1);
@@ -1959,11 +1963,13 @@
     if( res ){
       pc = pOp->p2-1;
     }
   }
   /* Undo any changes made by applyAffinity() to the input registers. */
+  assert( (pIn1->flags & MEM_Dyn) == (flags1 & MEM_Dyn) );
   pIn1->flags = flags1;
+  assert( (pIn3->flags & MEM_Dyn) == (flags3 & MEM_Dyn) );
   pIn3->flags = flags3;
   break;
 }
 
 /* Opcode: Permutation * * * P4 *