From: drh <drh@noemail.net>
Date: Fri, 23 Sep 2016 18:06:22 +0000 (+0000)
Subject: Fix the ORDER BY LIMIT optimization backport so that it works when the
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4427e597b217219b5a7a853e4a1007cc6bf35bb1;p=thirdparty%2Fsqlite.git

Fix the ORDER BY LIMIT optimization backport so that it works when the
ORDER BY uses the DESC direction.

FossilOrigin-Name: 0c3cafb7ebb887dbfa2652f8bf69b52ed265c344
---

diff --git a/manifest b/manifest
index a62fe6bd61..14c7a6db34 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Backport\sthe\sORDER\sBY\sLIMIT\soptimization\sto\sversion\s3.8.9.
-D 2016-09-14T01:43:24.978
+C Fix\sthe\sORDER\sBY\sLIMIT\soptimization\sbackport\sso\sthat\sit\sworks\swhen\sthe\nORDER\sBY\suses\sthe\sDESC\sdirection.
+D 2016-09-23T18:06:22.679
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 00d12636df7a5b08af09116bcd6c7bfd49b8b3b4
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -307,7 +307,7 @@ F src/vxworks.h c18586c8edc1bddbc15c004fa16aeb1e1342b4fb
 F src/wal.c 878c8e1a51cb2ec45c395d26b7d5cd9e1a098e4a
 F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
 F src/walker.c c253b95b4ee44b21c406e2a1052636c31ea27804
-F src/where.c 3028fd1c63c2c9a8f6897f839b01287a024b3ac9
+F src/where.c 8cb63bd44ed75c0abdee39a988255d94153fbb1e
 F src/whereInt.h 1d1fd0b3b9b56e08f5d3583c70a2c785a3c43941
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
@@ -698,7 +698,7 @@ F test/like.test 4f2a71d36a536233727f71995fef900756705e56
 F test/like2.test 3b2ee13149ba4a8a60b59756f4e5d345573852da
 F test/like3.test 7b0525a39e4f25c4fd113de7e2e28eb712dcdedf
 F test/limit.test 0c99a27a87b14c646a9d583c7c89fd06c352663e
-F test/limit2.test ac97b8d07060a0280162ba4159e4c0c765861127
+F test/limit2.test 7e7744cc548d7e4c92e1dd3edc30dd0f86adafd5
 F test/loadext.test 648cb95f324d1775c54a55c12271b2d1156b633b
 F test/loadext2.test 0408380b57adca04004247179837a18e866a74f7
 F test/lock.test b984ab9034e7389be0d863fe4e64cbbc4d2028f5
@@ -1250,10 +1250,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 8a8ffc862e96f57aa698f93de10dee28e69f6e09
-R cb2965d27bc117ed4d5058b40e772fea
-T *branch * branch-3.8.9
-T *sym-branch-3.8.9 *
-T -sym-trunk *
+P db3614825fa02ddacc76b85d76a37aad9d2a9dc8
+R 8fe93701829063e8060746a016609ed6
 U drh
-Z 9f0b78af32a328047c54447fa4f1ec76
+Z 16e3e2667c5c6f66c3599e3dc9698a2d
diff --git a/manifest.uuid b/manifest.uuid
index f18499c30d..5e3cf14f6a 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-db3614825fa02ddacc76b85d76a37aad9d2a9dc8
\ No newline at end of file
+0c3cafb7ebb887dbfa2652f8bf69b52ed265c344
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index 6ebe62fcec..ac59fcaab7 100644
--- a/src/where.c
+++ b/src/where.c
@@ -6272,7 +6272,7 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
       if( pWInfo->nOBSat<=0 ){
         pWInfo->nOBSat = 0;
         if( nLoop>0 && (pFrom->aLoop[nLoop-1]->wsFlags & WHERE_ONEROW)==0 ){
-          Bitmask m;
+          Bitmask m = 0;
           int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy, pFrom,
                       WHERE_ORDERBY_LIMIT, nLoop-1, pFrom->aLoop[nLoop-1], &m);
           if( rc==pWInfo->pOrderBy->nExpr ){
@@ -6281,7 +6281,6 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
           }
         }
       }
-      pWInfo->revMask = pFrom->revLoop;
     }
     if( (pWInfo->wctrlFlags & WHERE_SORTBYGROUP)
         && pWInfo->nOBSat==pWInfo->pOrderBy->nExpr
diff --git a/test/limit2.test b/test/limit2.test
index 0f82ab8d55..4d03180729 100644
--- a/test/limit2.test
+++ b/test/limit2.test
@@ -109,7 +109,15 @@ do_execsql_test limit2-310 {
   SELECT *,'.' FROM t300 WHERE a=0 AND (c=0 OR c=99) ORDER BY c DESC LIMIT 1;
 } {0 1 99 .}
 
-
-
+# Make sure the SELECT loop is ordered correctly for the direction of
+# the ORDER BY
+#
+do_execsql_test limit2-400 {
+  CREATE TABLE t400(a,b);
+  CREATE INDEX t400_ab ON t400(a,b);
+  INSERT INTO t400(a,b) VALUES(1,90),(1,40),(2,80),(2,30),(3,70),(3,20);
+  SELECT *,'x' FROM t400 WHERE a IN (1,2,3) ORDER BY b DESC LIMIT 3;
+  SELECT *,'y' FROM t400 WHERE a IN (1,2,3) ORDER BY +b DESC LIMIT 3;
+} {1 90 x 2 80 x 3 70 x 1 90 y 2 80 y 3 70 y}
 
 finish_test