From d43075bcaf7f427ee8124dc6cf43fb5971c64d3a Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Mon, 19 Sep 2016 02:19:00 +0000
Subject: [PATCH] Small performance optimization in the expression walker.

FossilOrigin-Name: c6e6afb9391704d9119335f2ce17df3968acb514
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/walker.c  |  2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/manifest b/manifest
index 8b2cc6c428..addc2705a4 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Revise\sthe\simplementation\sof\sOP_Once\sso\sthat\sit\sis\ssmaller,\sfaster,\sand\suses\nless\smemory.\s\sThis\salso\sfixes\san\sobscure\sbug\sintroduced\s3\sdays\sago\sby\scheck-in\n[5990a1bdb4a073].
-D 2016-09-18T16:08:10.162
+C Small\sperformance\soptimization\sin\sthe\sexpression\swalker.
+D 2016-09-19T02:19:00.600
 F Makefile.in 6fd48ffcf7c2deea7499062d1f3747f986c19678
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc e1aa788e84f926e42239ee167c53f785bedacacd
@@ -466,7 +466,7 @@ F src/vtab.c e02cacb5c7ae742631edeb9ae9f53d399f093fd8
 F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 02eeecc265f6ffd0597378f5d8ae9070b62a406a
 F src/wal.h 6dd221ed384afdc204bc61e25c23ef7fd5a511f2
-F src/walker.c 2d2cc7fb0f320f7f415215d7247f3c584141ac09
+F src/walker.c 83042807db1a27175fcb39be8f3e2a839dbdddb2
 F src/where.c d0ca1b5e1c56249e7725cea66ce4e172c5845dec
 F src/whereInt.h 14dd243e13b81cbb0a66063d38b70f93a7d6e613
 F src/wherecode.c e412e09abad1eea213d85594cf46db9f877db56d
@@ -1525,7 +1525,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P baceb988c6f4e93134e6a63173e846af2b73531a
-R 305c67fde695fcddb65717c9957658ad
+P 6bf5ba10d28f1b0a32aa9a560ae3143a1235eadb
+R 3576b7fe8bd045656543b2a44b86fd72
 U drh
-Z 45869286482c6f2c4387b12de5cab0cb
+Z 8bd385e2bfe7ba512e577302650c0d2b
diff --git a/manifest.uuid b/manifest.uuid
index f8b9f2bf1b..65b44f476e 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-6bf5ba10d28f1b0a32aa9a560ae3143a1235eadb
\ No newline at end of file
+c6e6afb9391704d9119335f2ce17df3968acb514
\ No newline at end of file
diff --git a/src/walker.c b/src/walker.c
index 82aae67a61..5abc3b9add 100644
--- a/src/walker.c
+++ b/src/walker.c
@@ -46,7 +46,7 @@ static SQLITE_NOINLINE int walkExpr(Walker *pWalker, Expr *pExpr){
   if( pExpr->pRight && walkExpr(pWalker, pExpr->pRight) ) return WRC_Abort;
   if( ExprHasProperty(pExpr, EP_xIsSelect) ){
     if( sqlite3WalkSelect(pWalker, pExpr->x.pSelect) ) return WRC_Abort;
-  }else{
+  }else if( pExpr->x.pList ){
     if( sqlite3WalkExprList(pWalker, pExpr->x.pList) ) return WRC_Abort;
   }
   return WRC_Continue;