Disallow the use of COLLATE clauses and the ASC and DESC keywords within

foreign key constraints and in the argument list to common table expressions.

FossilOrigin-Name: 83cbc4d8761498647794affffa961a4fca311be7

src/build.c

@@ -1321,7 +1321,7 @@ void sqlite3AddPrimaryKey(
   }
   if( nTerm==1
    && zType && sqlite3StrICmp(zType, "INTEGER")==0
-   && sortOrder==SQLITE_SO_ASC
+   && sortOrder!=SQLITE_SO_DESC
   ){
     pTab->iPKey = iCol;
     pTab->keyConf = (u8)onError;
@@ -2600,6 +2600,8 @@ void sqlite3CreateForeignKey(
 
   assert( pTo!=0 );
   if( p==0 || IN_DECLARE_VTAB ) goto fk_end;
+  sqlite3RestrictColumnListSyntax(pParse, pFromCol);
+  sqlite3RestrictColumnListSyntax(pParse, pToCol);
   if( pFromCol==0 ){
     int iCol = p->nCol-1;
     if( NEVER(iCol<0) ) goto fk_end;
@@ -3038,7 +3040,8 @@ Index *sqlite3CreateIndex(
     if( pList==0 ) goto exit_create_index;
     pList->a[0].zName = sqlite3DbStrDup(pParse->db,
                                         pTab->aCol[pTab->nCol-1].zName);
-    pList->a[0].sortOrder = (u8)sortOrder;
+    assert( pList->nExpr==1 );
+    sqlite3ExprListSetSortOrder(pList, sortOrder);
   }
 
   /* Figure out how many bytes of space are required to store explicitly
@@ -4283,6 +4286,32 @@ KeyInfo *sqlite3KeyInfoOfIndex(Parse *pParse, Index *pIdx){
   return pKey;
 }
 
+/*
+** Generate a syntax error if the expression list provided contains
+** any COLLATE or ASC or DESC keywords.
+**
+** Some legacy versions of SQLite allowed constructs like:
+**
+**      CREATE TABLE x(..., FOREIGN KEY(x COLLATE binary DESC) REFERENCES...);
+**                                        ^^^^^^^^^^^^^^^^^^^
+**
+** The COLLATE and sort order terms were ignored.  To prevent compatibility
+** problems in case something like this appears in a legacy sqlite_master
+** table, only enforce the restriction on new SQL statements, not when
+** parsing the schema out of the sqlite_master table.
+*/
+void sqlite3RestrictColumnListSyntax(Parse *pParse, ExprList *p){
+  int i;
+  if( p==0 || pParse->db->init.busy ) return;
+  for(i=0; i<p->nExpr; i++){
+    if( p->a[i].pExpr!=0 || p->a[i].bDefinedSO ){
+      sqlite3ErrorMsg(pParse, "syntax error after column name \"%w\"",
+                      p->a[i].zName);
+      return;
+    }
+  }
+}
+
 #ifndef SQLITE_OMIT_CTE
 /* 
 ** This routine is invoked once per CTE by the parser while parsing a 
@@ -4299,6 +4328,8 @@ With *sqlite3WithAdd(
   With *pNew;
   char *zName;
 
+  sqlite3RestrictColumnListSyntax(pParse, pArglist);
+
   /* Check that the CTE name is unique within this WITH clause. If
   ** not, store an error in the Parse structure. */
   zName = sqlite3NameFromToken(pParse->db, pName);

src/expr.c

@@ -1160,6 +1160,21 @@ no_mem:
   return 0;
 }
 
+/*
+** Set the sort order for the last element on the given ExprList.
+*/
+void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder){
+  if( p==0 ) return;
+  assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC>=0 && SQLITE_SO_DESC>0 );
+  assert( p->nExpr>0 );
+  if( iSortOrder<0 ){
+    assert( p->a[p->nExpr-1].sortOrder==SQLITE_SO_ASC );
+    return;
+  }
+  p->a[p->nExpr-1].sortOrder = (u8)iSortOrder;
+  p->a[p->nExpr-1].bDefinedSO = 1;
+}
+
 /*
 ** Set the ExprList.a[].zName element of the most recently added item
 ** on the expression list.

src/parse.y

@@ -680,18 +680,18 @@ orderby_opt(A) ::= .                          {A = 0;}
 orderby_opt(A) ::= ORDER BY sortlist(X).      {A = X;}
 sortlist(A) ::= sortlist(X) COMMA expr(Y) sortorder(Z). {
   A = sqlite3ExprListAppend(pParse,X,Y.pExpr);
-  if( A ) A->a[A->nExpr-1].sortOrder = (u8)Z;
+  sqlite3ExprListSetSortOrder(A,Z);
 }
 sortlist(A) ::= expr(Y) sortorder(Z). {
   A = sqlite3ExprListAppend(pParse,0,Y.pExpr);
-  if( A && ALWAYS(A->a) ) A->a[0].sortOrder = (u8)Z;
+  sqlite3ExprListSetSortOrder(A,Z);
 }
 
 %type sortorder {int}
 
 sortorder(A) ::= ASC.           {A = SQLITE_SO_ASC;}
 sortorder(A) ::= DESC.          {A = SQLITE_SO_DESC;}
-sortorder(A) ::= .              {A = SQLITE_SO_ASC;}
+sortorder(A) ::= .              {A = SQLITE_SO_UNDEFINED;}
 
 %type groupby_opt {ExprList*}
 %destructor groupby_opt {sqlite3ExprListDelete(pParse->db, $$);}
@@ -1229,14 +1229,14 @@ idxlist(A) ::= idxlist(X) COMMA nm(Y) collate(C) sortorder(Z).  {
   A = sqlite3ExprListAppend(pParse,X, p);
   sqlite3ExprListSetName(pParse,A,&Y,1);
   sqlite3ExprListCheckLength(pParse, A, "index");
-  if( A ) A->a[A->nExpr-1].sortOrder = (u8)Z;
+  sqlite3ExprListSetSortOrder(A,Z);
 }
 idxlist(A) ::= nm(Y) collate(C) sortorder(Z). {
   Expr *p = sqlite3ExprAddCollateToken(pParse, 0, &C, 1);
   A = sqlite3ExprListAppend(pParse,0, p);
   sqlite3ExprListSetName(pParse, A, &Y, 1);
   sqlite3ExprListCheckLength(pParse, A, "index");
-  if( A ) A->a[A->nExpr-1].sortOrder = (u8)Z;
+  sqlite3ExprListSetSortOrder(A,Z);
 }
 
 %type collate {Token}

src/sqliteInt.h

@@ -1525,6 +1525,7 @@ struct CollSeq {
 */
 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
+#define SQLITE_SO_UNDEFINED -1 /* No sort order specified */
 
 /*
 ** Column affinity types.
@@ -2189,6 +2190,7 @@ struct ExprList {
     unsigned done :1;       /* A flag to indicate when processing is finished */
     unsigned bSpanIsTab :1; /* zSpan holds DB.TABLE.COLUMN */
     unsigned reusable :1;   /* Constant expression is reusable */
+    unsigned bDefinedSO :1; /* True if either DESC or ASC keywords present */
     union {
       struct {
         u16 iOrderByCol;      /* For ORDER BY, column number in result set */
@@ -3244,6 +3246,7 @@ Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
 void sqlite3ExprDelete(sqlite3*, Expr*);
 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
+void sqlite3ExprListSetSortOrder(ExprList*,int);
 void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
 void sqlite3ExprListSetSpan(Parse*,ExprList*,ExprSpan*);
 void sqlite3ExprListDelete(sqlite3*, ExprList*);
@@ -3755,6 +3758,7 @@ const char *sqlite3JournalModename(int);
   int sqlite3Checkpoint(sqlite3*, int, int, int*, int*);
   int sqlite3WalDefaultHook(void*,sqlite3*,const char*,int);
 #endif
+void sqlite3RestrictColumnListSyntax(Parse*,ExprList*);
 #ifndef SQLITE_OMIT_CTE
   With *sqlite3WithAdd(Parse*,With*,Token*,ExprList*,Select*);
   void sqlite3WithDelete(sqlite3*,With*);