Provide the SQLITE_DIRECTONLY flag for app-defined functions that prohibits

the use of those functions within triggers or views.

FossilOrigin-Name: fc745845d8d76adc165575e2192f4176e3c28e614c72571d56f4011560499fe1

src/resolve.c

@@ -823,6 +823,15 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
           ** SQL is being compiled using sqlite3NestedParse() */
           no_such_func = 1;
           pDef = 0;
+        }else
+        if( (pDef->funcFlags & SQLITE_FUNC_DIRECT)!=0
+         && ExprHasProperty(pExpr, EP_Indirect)
+         && !IN_RENAME_OBJECT
+        ){
+          /* Functions tagged with SQLITE_DIRECTONLY may not be used
+          ** inside of triggers and views */
+          sqlite3ErrorMsg(pParse, "%s() prohibited in triggers and views",
+                          pDef->zName);
         }
       }