From 7248a8b2b95a99d7fb7af7e5a3481f9cfcb95e3e Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Mon, 4 Aug 2014 18:50:54 +0000
Subject: [PATCH] Further enhancements to IN-operator processing.

FossilOrigin-Name: 7fdf26da1d2f40b80f9e44ff6f5af22ace8f95f3
---
 manifest      | 14 +++++++-------
 manifest.uuid |  2 +-
 src/expr.c    | 25 +++++++++++++++----------
 src/update.c  |  5 +++--
 4 files changed, 26 insertions(+), 20 deletions(-)

diff --git a/manifest b/manifest
index d358a967d8..a6de05b0b9 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Refinements\sto\sthe\senhanced\sIN-operator\slogic.
-D 2014-08-04T16:39:39.657
+C Further\senhancements\sto\sIN-operator\sprocessing.
+D 2014-08-04T18:50:54.734
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5eb79e334a5de69c87740edd56af6527dd219308
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -176,7 +176,7 @@ F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c 0231df905e2c4abba4483ee18ffc05adc321df2a
 F src/date.c 593c744b2623971e45affd0bde347631bdfa4625
 F src/delete.c bcf8f72126cea80fc3d5bc5494cf19b3f8935aaf
-F src/expr.c 8f5e763623d79e71d60998a4e714324ca0e9380d
+F src/expr.c 8ac2d0e8a0c1bc84eba94ab39867ba4d07d84f75
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c 8545f3b36da47473e10800ea4fb0810fd4062514
 F src/func.c 3bc223ea36cd29a91c481485343d0ee4257ab8dc
@@ -279,7 +279,7 @@ F src/test_vfstrace.c bab9594adc976cbe696ff3970728830b4c5ed698
 F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/tokenize.c ae45399d6252b4d736af43bee1576ce7bff86aec
 F src/trigger.c 66f3470b03b52b395e839155786966e3e037fddb
-F src/update.c 01564b3c430f6c7b0a35afaf7aba7987206fa3a5
+F src/update.c 510c59a21bd8ba315db173b38d79688cc15261df
 F src/utf.c a0314e637768a030e6e84a957d0c4f6ba910cc05
 F src/util.c 3076bdd51cdbf60a6e2e57fada745be37133c73e
 F src/vacuum.c 3728d74919d4fb1356f9e9a13e27773db60b7179
@@ -1185,7 +1185,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 436e884215e2b33ca3fbb555362237b12827c07a
-R 0000d96605770a7d4078c73a9916f937
+P 92ba2821468ecbfac2469161d81c873de67b2243
+R d7c5ed9f11c47855b5c64fea1267f119
 U drh
-Z 246e982e6330087cd1ec561e7d991220
+Z 6f0f219998d1d32472de07ef9dc89d8e
diff --git a/manifest.uuid b/manifest.uuid
index 01804c86aa..bf4d5ed437 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-92ba2821468ecbfac2469161d81c873de67b2243
\ No newline at end of file
+7fdf26da1d2f40b80f9e44ff6f5af22ace8f95f3
\ No newline at end of file
diff --git a/src/expr.c b/src/expr.c
index 86787a9c34..6816d560d3 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1368,6 +1368,9 @@ int sqlite3ExprCanBeNull(const Expr *p){
     case TK_FLOAT:
     case TK_BLOB:
       return 0;
+    case TK_COLUMN:
+      assert( p->pTab!=0 );
+      return p->iColumn>=0 && p->pTab->aCol[p->iColumn].notNull==0;
     default:
       return 1;
   }
@@ -2038,16 +2041,18 @@ static void sqlite3ExprCodeIN(
     /* If the LHS is NULL, then the result is either false or NULL depending
     ** on whether the RHS is empty or not, respectively.
     */
-    if( destIfNull==destIfFalse ){
-      /* Shortcut for the common case where the false and NULL outcomes are
-      ** the same. */
-      sqlite3VdbeAddOp2(v, OP_IsNull, r1, destIfNull); VdbeCoverage(v);
-    }else{
-      int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, r1); VdbeCoverage(v);
-      sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse);
-      VdbeCoverage(v);
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
-      sqlite3VdbeJumpHere(v, addr1);
+    if( sqlite3ExprCanBeNull(pExpr->pLeft) ){
+      if( destIfNull==destIfFalse ){
+        /* Shortcut for the common case where the false and NULL outcomes are
+        ** the same. */
+        sqlite3VdbeAddOp2(v, OP_IsNull, r1, destIfNull); VdbeCoverage(v);
+      }else{
+        int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, r1); VdbeCoverage(v);
+        sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse);
+        VdbeCoverage(v);
+        sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
+        sqlite3VdbeJumpHere(v, addr1);
+      }
     }
   
     if( eType==IN_INDEX_ROWID ){
diff --git a/src/update.c b/src/update.c
index 3e04e00316..fe717a2ac1 100644
--- a/src/update.c
+++ b/src/update.c
@@ -437,8 +437,9 @@ void sqlite3Update(
       VdbeCoverageNeverTaken(v);
     }
     labelContinue = labelBreak;
-    sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak);
-    VdbeCoverage(v);
+    if( pPk==0 ){
+      sqlite3VdbeAddOp2(v, OP_IsNull, regOldRowid, labelBreak); VdbeCoverage(v);
+    }
   }else if( pPk ){
     labelContinue = sqlite3VdbeMakeLabel(v);
     sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v);