Do not allow parameters in a DEFAULT clause of a CREATE TABLE statement.

Ticket [78c0c8c3c9f7c1].

FossilOrigin-Name: 1ad2bc1ed4c4ac81ac67a9660761f0eeb47c7fef

1 files changed, 33 insertions, 11 deletions

diff --git a/src/expr.c b/src/expr.c
index c8e8e7826..57e462ea6 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1212,32 +1212,40 @@ void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
 /*
 ** These routines are Walker callbacks.  Walker.u.pi is a pointer
 ** to an integer.  These routines are checking an expression to see
-** if it is a constant.  Set *Walker.u.pi to 0 if the expression is
+** if it is a constant.  Set *Walker.u.i to 0 if the expression is
 ** not constant.
 **
 ** These callback routines are used to implement the following:
 **
-**     sqlite3ExprIsConstant()
-**     sqlite3ExprIsConstantNotJoin()
-**     sqlite3ExprIsConstantOrFunction()
+**     sqlite3ExprIsConstant()                  pWalker->u.i==1
+**     sqlite3ExprIsConstantNotJoin()           pWalker->u.i==2
+**     sqlite3ExprIsConstantOrFunction()        pWalker->u.i==3 or 4
 **
+** The sqlite3ExprIsConstantOrFunction() is used for evaluating expressions
+** in a CREATE TABLE statement.  The Walker.u.i value is 4 when parsing
+** an existing schema and 3 when processing a new statement.  A bound
+** parameter raises an error for new statements, but is silently converted
+** to NULL for existing schemas.  This allows sqlite_master tables that 
+** contain a bound parameter because they were generated by older versions
+** of SQLite to be parsed by newer versions of SQLite without raising a
+** malformed schema error.
 */
 static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
 
-  /* If pWalker->u.i is 3 then any term of the expression that comes from
+  /* If pWalker->u.i is 2 then any term of the expression that comes from
   ** the ON or USING clauses of a join disqualifies the expression
   ** from being considered constant. */
-  if( pWalker->u.i==3 && ExprHasProperty(pExpr, EP_FromJoin) ){
+  if( pWalker->u.i==2 && ExprHasProperty(pExpr, EP_FromJoin) ){
     pWalker->u.i = 0;
     return WRC_Abort;
   }
 
   switch( pExpr->op ){
     /* Consider functions to be constant if all their arguments are constant
-    ** and either pWalker->u.i==2 or the function as the SQLITE_FUNC_CONST
+    ** and either pWalker->u.i==3 or 4 or the function as the SQLITE_FUNC_CONST
     ** flag. */
     case TK_FUNCTION:
-      if( pWalker->u.i==2 || ExprHasProperty(pExpr,EP_Constant) ){
+      if( pWalker->u.i>=3 || ExprHasProperty(pExpr,EP_Constant) ){
         return WRC_Continue;
       }
       /* Fall through */
@@ -1251,6 +1259,19 @@ static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
       testcase( pExpr->op==TK_AGG_COLUMN );
       pWalker->u.i = 0;
       return WRC_Abort;
+    case TK_VARIABLE:
+      if( pWalker->u.i==4 ){
+        /* Silently convert bound parameters that appear inside of CREATE
+        ** statements into a NULL when parsing the CREATE statement text out
+        ** of the sqlite_master table */
+        pExpr->op = TK_NULL;
+      }else if( pWalker->u.i==3 ){
+        /* A bound parameter in a CREATE statement that originates from
+        ** sqlite3_prepare() causes an error */
+        pWalker->u.i = 0;
+        return WRC_Abort;
+      }
+      /* Fall through */
     default:
       testcase( pExpr->op==TK_SELECT ); /* selectNodeIsConstant will disallow */
       testcase( pExpr->op==TK_EXISTS ); /* selectNodeIsConstant will disallow */
@@ -1291,7 +1312,7 @@ int sqlite3ExprIsConstant(Expr *p){
 ** an ON or USING clause.
 */
 int sqlite3ExprIsConstantNotJoin(Expr *p){
-  return exprIsConst(p, 3);
+  return exprIsConst(p, 2);
 }
 
 /*
@@ -1303,8 +1324,9 @@ int sqlite3ExprIsConstantNotJoin(Expr *p){
 ** is considered a variable but a single-quoted string (ex: 'abc') is
 ** a constant.
 */
-int sqlite3ExprIsConstantOrFunction(Expr *p){
-  return exprIsConst(p, 2);
+int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){
+  assert( isInit==0 || isInit==1 );
+  return exprIsConst(p, 3+isInit);
 }
 
 /*