Block edgy functions used in DEFAULT constraints.

FossilOrigin-Name: da434dc149786e4b1cd80b3b2b25f8b614d0dec62d5439f839a66b536999e398

1 files changed, 21 insertions, 7 deletions

diff --git a/src/expr.c b/src/expr.c
index a9d59cfa6..994e3fe07 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1971,10 +1971,11 @@ Expr *sqlite3ExprSimplifiedAndOr(Expr *pExpr){
 ** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
 ** is found to not be a constant.
 **
-** The sqlite3ExprIsConstantOrFunction() is used for evaluating expressions
-** in a CREATE TABLE statement.  The Walker.eCode value is 5 when parsing
-** an existing schema and 4 when processing a new statement.  A bound
-** parameter raises an error for new statements, but is silently converted
+** The sqlite3ExprIsConstantOrFunction() is used for evaluating DEFAULT
+** expressions in a CREATE TABLE statement.  The Walker.eCode value is 5
+** when parsing an existing schema out of the sqlite_master table and 4
+** when processing a new CREATE TABLE 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
@@ -1998,6 +1999,7 @@ static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
       if( (pWalker->eCode>=4 || ExprHasProperty(pExpr,EP_ConstFunc))
        && !ExprHasProperty(pExpr, EP_WinFunc)
       ){
+        if( pWalker->eCode==5 ) ExprSetProperty(pExpr, EP_FromDDL);
         return WRC_Continue;
       }else{
         pWalker->eCode = 0;
@@ -2161,9 +2163,21 @@ int sqlite3ExprIsConstantOrGroupBy(Parse *pParse, Expr *p, ExprList *pGroupBy){
 }
 
 /*
-** Walk an expression tree.  Return non-zero if the expression is constant
-** or a function call with constant arguments.  Return and 0 if there
-** are any variables.
+** Walk an expression tree for the DEFAULT field of a column definition
+** in a CREATE TABLE statement.  Return non-zero if the expression is 
+** acceptable for use as a DEFAULT.  That is to say, return non-zero if
+** the expression is constant or a function call with constant arguments.
+** Return and 0 if there are any variables.
+**
+** isInit is true when parsing from sqlite_master.  isInit is false when
+** processing a new CREATE TABLE statement.  When isInit is true, parameters
+** (such as ? or $abc) in the expression are converted into NULL.  When
+** isInit is false, parameters raise an error.  Parameters should not be
+** allowed in a CREATE TABLE statement, but some legacy versions of SQLite
+** allowed it, so we need to support it when reading sqlite_master for
+** backwards compatibility.
+**
+** If isInit is true, set EP_FromDDL on every TK_FUNCTION node.
 **
 ** For the purposes of this function, a double-quoted string (ex: "abc")
 ** is considered a variable but a single-quoted string (ex: 'abc') is