NULL values are distinct. A comparison involving a NULL is always false.

Operations on a NULL value yield a NULL result.  This change makes SQLite
operate more like the SQL spec, but it may break existing applications that
assumed the old behavior.  All the old tests pass but we still need to add
new tests to better verify the new behavior.  Fix for ticket #44. (CVS 589)

FossilOrigin-Name: 9051173742f1b0e15a809d12a0c9c98fd2c4614d

1 files changed, 12 insertions, 14 deletions

diff --git a/src/insert.c b/src/insert.c
index 53c3e7696..1c9b9b4cb 100644
--- a/src/insert.c
+++ b/src/insert.c
@@ -12,7 +12,7 @@
 ** This file contains C code routines that are called by the parser
 ** to handle INSERT statements in SQLite.
 **
-** $Id: insert.c,v 1.58 2002/05/24 02:04:33 drh Exp $
+** $Id: insert.c,v 1.59 2002/05/26 20:54:33 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -290,14 +290,12 @@ void sqliteInsert(
       if( srcTab>=0 ){
         sqliteVdbeAddOp(v, OP_Column, srcTab, keyColumn);
       }else{
-        int addr;
         sqliteExprCode(pParse, pList->a[keyColumn].pExpr);
 
         /* If the PRIMARY KEY expression is NULL, then use OP_NewRecno
         ** to generate a unique primary key value.
         */
-        addr = sqliteVdbeAddOp(v, OP_Dup, 0, 1);
-        sqliteVdbeAddOp(v, OP_NotNull, 0, addr+4);
+        sqliteVdbeAddOp(v, OP_NotNull, -1, sqliteVdbeCurrentAddr(v)+3);
         sqliteVdbeAddOp(v, OP_Pop, 1, 0);
         sqliteVdbeAddOp(v, OP_NewRecno, base, 0);
       }
@@ -499,7 +497,7 @@ void sqliteGenerateConstraintChecks(
   int iCur;
   Index *pIdx;
   int seenReplace = 0;
-  int jumpInst;
+  int jumpInst1, jumpInst2;
   int contAddr;
   int hasTwoRecnos = (isUpdate && recnoChng);
 
@@ -527,7 +525,7 @@ void sqliteGenerateConstraintChecks(
       onError = OE_Abort;
     }
     sqliteVdbeAddOp(v, OP_Dup, nCol-1-i, 1);
-    addr = sqliteVdbeAddOp(v, OP_NotNull, 0, 0);
+    addr = sqliteVdbeAddOp(v, OP_NotNull, 1, 0);
     switch( onError ){
       case OE_Rollback:
       case OE_Abort:
@@ -565,14 +563,13 @@ void sqliteGenerateConstraintChecks(
       if( onError==OE_Default ) onError = OE_Abort;
     }
     if( onError!=OE_Replace ){
-      int jumpInst2;
       if( isUpdate ){
         sqliteVdbeAddOp(v, OP_Dup, nCol+1, 1);
         sqliteVdbeAddOp(v, OP_Dup, nCol+1, 1);
-        jumpInst2 = sqliteVdbeAddOp(v, OP_Eq, 0, 0);
+        jumpInst1 = sqliteVdbeAddOp(v, OP_Eq, 0, 0);
       }
       sqliteVdbeAddOp(v, OP_Dup, nCol, 1);
-      jumpInst = sqliteVdbeAddOp(v, OP_NotExists, base, 0);
+      jumpInst2 = sqliteVdbeAddOp(v, OP_NotExists, base, 0);
       switch( onError ){
         case OE_Rollback:
         case OE_Abort:
@@ -588,9 +585,9 @@ void sqliteGenerateConstraintChecks(
         default: assert(0);
       }
       contAddr = sqliteVdbeCurrentAddr(v);
-      sqliteVdbeChangeP2(v, jumpInst, contAddr);
+      sqliteVdbeChangeP2(v, jumpInst2, contAddr);
       if( isUpdate ){
-        sqliteVdbeChangeP2(v, jumpInst2, contAddr);
+        sqliteVdbeChangeP2(v, jumpInst1, contAddr);
         sqliteVdbeAddOp(v, OP_Dup, nCol+1, 1);
         sqliteVdbeAddOp(v, OP_MoveTo, base, 0);
       }
@@ -609,7 +606,7 @@ void sqliteGenerateConstraintChecks(
         sqliteVdbeAddOp(v, OP_Dup, i+extra+nCol-idx, 1);
       }
     }
-    sqliteVdbeAddOp(v, OP_MakeIdxKey, pIdx->nColumn, 0);
+    jumpInst1 = sqliteVdbeAddOp(v, OP_MakeIdxKey, pIdx->nColumn, 0);
     onError = pIdx->onError;
     if( onError==OE_None ) continue;
     if( overrideError!=OE_Default ){
@@ -619,7 +616,7 @@ void sqliteGenerateConstraintChecks(
       if( onError==OE_Default ) onError = OE_Abort;
     }
     sqliteVdbeAddOp(v, OP_Dup, extra+nCol+1+hasTwoRecnos, 1);
-    jumpInst = sqliteVdbeAddOp(v, OP_IsUnique, base+iCur+1, 0);
+    jumpInst2 = sqliteVdbeAddOp(v, OP_IsUnique, base+iCur+1, 0);
     switch( onError ){
       case OE_Rollback:
       case OE_Abort:
@@ -645,7 +642,8 @@ void sqliteGenerateConstraintChecks(
       default: assert(0);
     }
     contAddr = sqliteVdbeCurrentAddr(v);
-    sqliteVdbeChangeP2(v, jumpInst, contAddr);
+    sqliteVdbeChangeP2(v, jumpInst1, contAddr);
+    sqliteVdbeChangeP2(v, jumpInst2, contAddr);
   }
 }