From 461c281a2e6bcc91d7893c8069a2dea0d6273ab5 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Thu, 30 May 2002 02:35:11 +0000
Subject: [PATCH] Bug fix: bad code was generated for when the first operand of
 a CASE was NULL. (CVS 598)

FossilOrigin-Name: 4debc8db929fdc201759ba211acdeadc4e30e8af
---
 manifest       | 14 +++++++-------
 manifest.uuid  |  2 +-
 src/expr.c     |  9 +++++----
 test/expr.test |  6 ++++--
 4 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/manifest b/manifest
index 9a8c52ed43..be60bc683a 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Built-in\saggregate\sfunctions\s(MIN,\sSUM,\sAVG,\setc)\sshould\signore\sNULL\sentires.\s(CVS\s597)
-D 2002-05-29T23:22:23
+C Bug\sfix:\sbad\scode\swas\sgenerated\sfor\swhen\sthe\sfirst\soperand\sof\sa\sCASE\nwas\sNULL.\s(CVS\s598)
+D 2002-05-30T02:35:12
 F Makefile.in 6291a33b87d2a395aafd7646ee1ed562c6f2c28c
 F Makefile.template 4e11752e0b5c7a043ca50af4296ec562857ba495
 F README a4c0ba11354ef6ba0776b400d057c59da47a4cc0
@@ -23,7 +23,7 @@ F src/btree.h 8abeabfe6e0b1a990b64fa457592a6482f6674f3
 F src/build.c 36e42718a7a94f554ea39508993378482f5335c7
 F src/delete.c a2b098cbbf518e6b641847e26de85827793bc523
 F src/encode.c 346b12b46148506c32038524b95c4631ab46d760
-F src/expr.c 1a7a2f5f2b7dd37659783cdb6efaac74a092ba71
+F src/expr.c 86f0c6f26f8b573883ba3219bd91bac5d4618f6b
 F src/func.c 2cd4922913234ad384ccb75dd41bc35259a8338c
 F src/hash.c 6a6236b89c8c060c65dabd300a1c8ce7c10edb72
 F src/hash.h dca065dda89d4575f3176e75e9a3dc0f4b4fb8b9
@@ -63,7 +63,7 @@ F test/btree3.test 9caa9e22491dd8cd8aa36d7ac3b48b089817c895
 F test/conflict.test 5149646703d3930c9111068b5cda7e2e938476e3
 F test/copy.test b3cefcb520c64d7e7dfedbab06b4d4c31fa5b99a
 F test/delete.test c904a62129fe102b314a96111a8417f10249e4d8
-F test/expr.test 518ee35ec8d2c8883544d75a031219c75391fb21
+F test/expr.test ff6fceb9958f94ae3ca23dcc47aff7830b8131bc
 F test/func.test 628ab513b0d9c54251a63e026a26b7b4347e54ab
 F test/in.test c09312672e3f0709fa02c8e2e9cd8fb4bd6269aa
 F test/index.test c8a471243bbf878974b99baf5badd59407237cf3
@@ -135,7 +135,7 @@ F www/speed.tcl da8afcc1d3ccc5696cfb388a68982bc3d9f7f00f
 F www/sqlite.tcl 8b5884354cb615049aed83039f8dfe1552a44279
 F www/tclsqlite.tcl 1db15abeb446aad0caf0b95b8b9579720e4ea331
 F www/vdbe.tcl 2013852c27a02a091d39a766bc87cff329f21218
-P ed11abc81e638c21ec1aa0445a6d59de91343095
-R 0dbe1e91bf7fd44e5ab325282618e3b3
+P 19ae12bef210ae5fe171f10833faa38d640c129f
+R 1129c1b4d523e26221972965ea9f1b0e
 U drh
-Z c098e63f0d01ca947f8ca615049ab0d0
+Z 13527e062fc395d3f1e89758ab03474f
diff --git a/manifest.uuid b/manifest.uuid
index 14072de20a..9ce633c340 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-19ae12bef210ae5fe171f10833faa38d640c129f
\ No newline at end of file
+4debc8db929fdc201759ba211acdeadc4e30e8af
\ No newline at end of file
diff --git a/src/expr.c b/src/expr.c
index 89508d26c5..25f0ebd0bc 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -12,7 +12,7 @@
 ** This file contains routines used for analyzing expressions and
 ** for generating VDBE code that evaluates expressions in SQLite.
 **
-** $Id: expr.c,v 1.64 2002/05/26 20:54:33 drh Exp $
+** $Id: expr.c,v 1.65 2002/05/30 02:35:12 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -935,6 +935,7 @@ void sqliteExprCode(Parse *pParse, Expr *pExpr){
       int expr_end_label;
       int null_result_label;
       int jumpInst;
+      int nullBypassInst;
       int addr;
       int nExpr;
       int i;
@@ -947,7 +948,7 @@ void sqliteExprCode(Parse *pParse, Expr *pExpr){
       null_result_label = sqliteVdbeMakeLabel(v);
       if( pExpr->pLeft ){
         sqliteExprCode(pParse, pExpr->pLeft);
-        sqliteVdbeAddOp(v, OP_IsNull, -1, expr_end_label);
+        nullBypassInst = sqliteVdbeAddOp(v, OP_IsNull, -1, 0);
       }
       for(i=0; i<nExpr; i=i+2){
         sqliteExprCode(pParse, pExpr->pList->a[i].pExpr);
@@ -980,6 +981,7 @@ void sqliteExprCode(Parse *pParse, Expr *pExpr){
       if( pExpr->pLeft ){
         sqliteVdbeAddOp(v, OP_Pull, 1, 0);
         sqliteVdbeAddOp(v, OP_Pop, 1, 0);
+        sqliteVdbeChangeP2(v, nullBypassInst, sqliteVdbeCurrentAddr(v));
       }
     }
     break;
@@ -1164,8 +1166,7 @@ void sqliteExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
     }
     default: {
       sqliteExprCode(pParse, pExpr);
-      sqliteVdbeAddOp(v, OP_Not, 0, 0);
-      sqliteVdbeAddOp(v, OP_If, jumpIfNull, dest);
+      sqliteVdbeAddOp(v, OP_IfNot, jumpIfNull, dest);
       break;
     }
   }
diff --git a/test/expr.test b/test/expr.test
index 2d2a96a0b2..799fd775b7 100644
--- a/test/expr.test
+++ b/test/expr.test
@@ -11,7 +11,7 @@
 # This file implements regression tests for SQLite library.  The
 # focus of this file is testing expressions.
 #
-# $Id: expr.test,v 1.21 2002/05/27 01:04:51 drh Exp $
+# $Id: expr.test,v 1.22 2002/05/30 02:35:12 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -352,7 +352,9 @@ test_expr expr-case.9 {i1=3} \
 	{CASE i1 WHEN 1 THEN 'one' WHEN 2 THEN 'two' ELSE 'error' END} error
 test_expr expr-case.10 {i1=3} \
 	{CASE i1 WHEN 1 THEN 'one' WHEN 2 THEN 'two' END} {{}}
-test_expr expr-case.11 {i1=7} \
+test_expr expr-case.11 {i1=null} \
+	{CASE i1 WHEN 1 THEN 'one' WHEN 2 THEN 'two' ELSE 3 END} {{}}
+test_expr expr-case.12 {i1=7} \
 	{ CASE WHEN i1 < 5 THEN 'low' 
 	       WHEN i1 < 10 THEN 'medium' 
                WHEN i1 < 15 THEN 'high' ELSE 'error' END} medium