Ensure that the KeyInfo.nXField value for ephemeral tables used to implement

ORDER BY or GROUP BY clauses is set correctly, so that the
sqlite3VdbeFindCompare() routine can choose the correct comparison function.
Add assert() statements to the high-speed comparison functions to detect
cases where they are inappropriately chosen.
Fix for ticket [f97c4637102a3ae72b7911].

FossilOrigin-Name: f7201bb0cdc9e1425c68599b32434de2231dca36

manifest

@@ -1,5 +1,5 @@
-C Fix\scompilation\son\sCygwin\swhen\sSQLITE_MAX_WORKER_THREADS\sis\sgreater\sthan\szero.
-D 2015-01-19T20:05:53.508
+C Ensure\sthat\sthe\sKeyInfo.nXField\svalue\sfor\sephemeral\stables\sused\sto\simplement\nORDER\sBY\sor\sGROUP\sBY\sclauses\sis\sset\scorrectly,\sso\sthat\sthe\nsqlite3VdbeFindCompare()\sroutine\scan\schoose\sthe\scorrect\scomparison\sfunction.\nAdd\sassert()\sstatements\sto\sthe\shigh-speed\scomparison\sfunctions\sto\sdetect\ncases\swhere\sthey\sare\sinappropriately\schosen.\nFix\sfor\sticket\s[f97c4637102a3ae72b7911].
+D 2015-01-19T21:36:05.317
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5407a688f4d77a05c18a8142be8ae5a2829dd610
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -229,7 +229,7 @@ F src/printf.c ea82bcb1b83273b4c67177c233c1f78c81fc42f9
 F src/random.c ba2679f80ec82c4190062d756f22d0c358180696
 F src/resolve.c f6c46d3434439ab2084618d603e6d6dbeb0d6ada
 F src/rowset.c eccf6af6d620aaa4579bd3b72c1b6395d9e9fa1e
-F src/select.c e4c38c75e36f28aed80a69a725d888751bfd53df
+F src/select.c bc02e8b084891af5a3b428faa9cf367aff887d1a
 F src/shell.c d2d3b46701e44369dd314bd6817541c60e2c39ea
 F src/sqlite.h.in 9dfc99d6533d36d6a549c4f3f01cacc8be956ada
 F src/sqlite3.rc 992c9f5fb8285ae285d6be28240a7e8d3a7f2bad
@@ -296,7 +296,7 @@ F src/vdbe.c ddfc977981cd6324668aa6b114045eb1c677421a
 F src/vdbe.h 6fc69d9c5e146302c56e163cb4b31d1ee64a18c3
 F src/vdbeInt.h 9bb69ff2447c34b6ccc58b34ec35b615f86ead78
 F src/vdbeapi.c 4bc511a46b9839392ae0e90844a71dc96d9dbd71
-F src/vdbeaux.c 07ef87c6d4b5abdf13ff33babb10205702fdab0a
+F src/vdbeaux.c f06d38c71d7f533348c09869d69fd1b647042a5b
 F src/vdbeblob.c 4af4bfb71f6df7778397b4a0ebc1879793276778
 F src/vdbemem.c 31d8eabb0cd78bfeab4e5124c7363c3e9e54db9f
 F src/vdbesort.c 6d64c5448b64851b99931ede980addc3af70d5e2
@@ -769,6 +769,7 @@ F test/orderby4.test 4d39bfbaaa3ae64d026ca2ff166353d2edca4ba4
 F test/orderby5.test 8f08a54836d21fb7c70245360751aedd1c2286fb
 F test/orderby6.test 8b38138ab0972588240b3fca0985d2e400432859
 F test/orderby7.test 3d1383d52ade5b9eb3a173b3147fdd296f0202da
+F test/orderby8.test 23ef1a5d72bd3adcc2f65561c654295d1b8047bd
 F test/oserror.test 14fec2796c2b6fe431c7823750e8a18a761176d7
 F test/ovfl.test 4f7ca651cba5c059a12d8c67dddd49bec5747799
 F test/pager1.test 1acbdb14c5952a72dd43129cabdbf69aaa3ed1fa
@@ -1236,7 +1237,8 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 824328f9833d01fc155a9d0265ef41d338cf1ffb
-R 46d0fc0085c932a30f59bac1bd145cf7
-U mistachkin
-Z 998ddd7b1750b28ed4b199120a25244e
+P 2037442c582e51d85967bc911ea4a412eb4da573 e02959b9a0e1bacdd3939548d4434c042aacc2e6
+R 5021170f2a6880b445a702735148b9c6
+T +closed e02959b9a0e1bacdd3939548d4434c042aacc2e6
+U drh
+Z b76cf3617d76194e2b83c38054737fb3

manifest.uuid

@@ -1 +1 @@
-2037442c582e51d85967bc911ea4a412eb4da573
+f7201bb0cdc9e1425c68599b32434de2231dca36

src/select.c

@@ -1054,7 +1054,7 @@ static KeyInfo *keyInfoFromExprList(
   int i;
 
   nExpr = pList->nExpr;
-  pInfo = sqlite3KeyInfoAlloc(db, nExpr+nExtra-iStart, 1);
+  pInfo = sqlite3KeyInfoAlloc(db, nExpr-iStart, nExtra+1);
   if( pInfo ){
     assert( sqlite3KeyInfoIsWriteable(pInfo) );
     for(i=iStart, pItem=pList->a+iStart; i<nExpr; i++, pItem++){
@@ -4924,7 +4924,7 @@ int sqlite3Select(
   */
   if( sSort.pOrderBy ){
     KeyInfo *pKeyInfo;
-    pKeyInfo = keyInfoFromExprList(pParse, sSort.pOrderBy, 0, 0);
+    pKeyInfo = keyInfoFromExprList(pParse, sSort.pOrderBy, 0, pEList->nExpr);
     sSort.iECursor = pParse->nTab++;
     sSort.addrSortIndex =
       sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
@@ -5098,7 +5098,7 @@ int sqlite3Select(
       ** will be converted into a Noop.  
       */
       sAggInfo.sortingIdx = pParse->nTab++;
-      pKeyInfo = keyInfoFromExprList(pParse, pGroupBy, 0, 0);
+      pKeyInfo = keyInfoFromExprList(pParse, pGroupBy, 0, sAggInfo.nColumn);
       addrSortingIdx = sqlite3VdbeAddOp4(v, OP_SorterOpen, 
           sAggInfo.sortingIdx, sAggInfo.nSortingColumn, 
           0, (char*)pKeyInfo, P4_KEYINFO);

src/vdbeaux.c

@@ -3349,6 +3349,41 @@ debugCompareEnd:
 }
 #endif
 
+#if SQLITE_DEBUG
+/*
+** Count the number of fields (a.k.a. columns) in the record given by
+** pKey,nKey.  The verify that this count is less than or equal to the
+** limit given by pKeyInfo->nField + pKeyInfo->nXField.
+**
+** If this constraint is not satisfied, it means that the high-speed
+** vdbeRecordCompareInt() and vdbeRecordCompareString() routines will
+** not work correctly.  If this assert() ever fires, it probably means
+** that the KeyInfo.nField or KeyInfo.nXField values were computed
+** incorrectly.
+*/
+static void vdbeAssertFieldCountWithinLimits(
+  int nKey, const void *pKey,   /* The record to verify */ 
+  const KeyInfo *pKeyInfo       /* Compare size with this KeyInfo */
+){
+  int nField = 0;
+  u32 szHdr;
+  u32 idx;
+  u32 notUsed;
+  const unsigned char *aKey = (const unsigned char*)pKey;
+
+  if( CORRUPT_DB ) return;
+  idx = getVarint32(aKey, szHdr);
+  assert( szHdr<=nKey );
+  while( idx<szHdr ){
+    idx += getVarint32(aKey+idx, notUsed);
+    nField++;
+  }
+  assert( nField <= pKeyInfo->nField+pKeyInfo->nXField );
+}
+#else
+# define vdbeAssertFieldCountWithinLimits(A,B,C)
+#endif
+
 /*
 ** Both *pMem1 and *pMem2 contain string values. Compare the two values
 ** using the collation sequence pColl. As usual, return a negative , zero
@@ -3760,6 +3795,7 @@ static int vdbeRecordCompareInt(
   i64 v = pPKey2->aMem[0].u.i;
   i64 lhs;
 
+  vdbeAssertFieldCountWithinLimits(nKey1, pKey1, pPKey2->pKeyInfo);
   assert( (*(u8*)pKey1)<=0x3F || CORRUPT_DB );
   switch( serial_type ){
     case 1: { /* 1-byte signed integer */
@@ -3847,6 +3883,7 @@ static int vdbeRecordCompareString(
   int serial_type;
   int res;
 
+  vdbeAssertFieldCountWithinLimits(nKey1, pKey1, pPKey2->pKeyInfo);
   getVarint32(&aKey1[1], serial_type);
   if( serial_type<12 ){
     res = pPKey2->r1;      /* (pKey1/nKey1) is a number or a null */

test/orderby8.test

@@ -0,0 +1,41 @@
+# 2015-01-19
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing ORDER BY and LIMIT on tables with
+# many columns.
+#
+# These tests verify that ticket [f97c4637102a3ae72b7911167e1d4da12ce60722]
+# from 2015-01-19 has been fixed.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set ::testprefix orderby8
+
+do_test 1.0 {
+  db eval {
+    CREATE TABLE t1(x);
+    INSERT INTO t1(x) VALUES(1),(5),(9),(7),(3),(2),(4),(6),(8);
+  }
+  set ::result_set "x"
+} {x}
+for {set i 1} {$i<200} {incr i} {
+  append ::result_set ", x+$i"
+  do_test 1.$i {
+    set res {}
+    db eval "SELECT $::result_set FROM t1 ORDER BY x LIMIT -1" {
+      lappend res $x
+    }
+    set res
+  } {1 2 3 4 5 6 7 8 9}
+}
+
+finish_test