Detect and handles the case where a row is modified or deleted while it
is being read during SELECT processing. (CVS 5399)
FossilOrigin-Name: c80a5d09935c60a2a50bc262c172a94073355f0d
diff --git a/manifest b/manifest
index 058bd32..ab9b95b 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Tweak\sto\sthe\s".timer"\scommand\sin\sthe\sCLI\sto\shelp\sit\swork\sbetter\swith\sGCC.\s(CVS\s5398)
-D 2008-07-11T17:23:25
+C Detect\sand\shandles\sthe\scase\swhere\sa\srow\sis\smodified\sor\sdeleted\swhile\sit\nis\sbeing\sread\sduring\sSELECT\sprocessing.\s(CVS\s5399)
+D 2008-07-11T21:02:54
F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
F Makefile.in a03f7cb4f7ad50bc53a788c6c544430e81f95de4
F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -95,9 +95,9 @@
F src/auth.c c8b2ab5c8bad4bd90ed7c294694f48269162c627
F src/bitvec.c 95c86bd18d8fedf0533f5af196192546e10a7e7d
F src/btmutex.c 483ced3c52205b04b97df69161fadbf87f4f1ea2
-F src/btree.c 8d08214728e231ba9ee2753bb224abbfddad6a6c
-F src/btree.h 0063e9853aa1ffb55b46f0e798eea8934f032ffd
-F src/btreeInt.h d59e58d39950a17c0fb7e004c90ab7696d3e7df5
+F src/btree.c dcbb9624c99e53cbb1d63e1c980fc9e93a02a06b
+F src/btree.h 03256ed7ee42b5ecacbe887070b0f8249e7d069d
+F src/btreeInt.h 346cef00620c91dd7c632b57defd1332d0847edc
F src/build.c bac7233d984be3805aaa41cf500f7ee12dc97249
F src/callback.c aa492a0ad8c2d454edff9fb8a57fae13743cf71d
F src/complete.c cb14e06dbe79dee031031f0d9e686ff306afe07c
@@ -140,7 +140,7 @@
F src/prepare.c c9bb0aacb7a571d049805699ed18f2bb136ea091
F src/printf.c 8e5d410220cf8650f502caf71f0de979a3f9031e
F src/random.c 5c754319d38abdd6acd74601ee0105504adc508a
-F src/select.c fcf51df1818a448edebf55b032d89771ba4536ef
+F src/select.c b909e21358f141627d1cadfdfbdb43ec08ed0a4b
F src/shell.c 4b835fe734304ac22a3385868cd3790c1e4f7aa1
F src/sqlite.h.in a573ab3a22256fc6c28b8f27d5af446f2b712a31
F src/sqlite3ext.h 1e3887c9bd3ae66cb599e922824b04cd0d0f2c3e
@@ -160,10 +160,10 @@
F src/test9.c 904ebe0ed1472d6bad17a81e2ecbfc20017dc237
F src/test_async.c da9f58f49faccd3a26ba89f58de125862351b6e2
F src/test_autoext.c f53b0cdf7bf5f08100009572a5d65cdb540bd0ad
-F src/test_btree.c fd982a4242449a462f5a87f120d6e8fcc5e24a83
+F src/test_btree.c af13f421952807ceba599bdb63b652ac68cd6c9f
F src/test_config.c 7d3c3bb37e12d8ed22c5e0900e1361178b0580a3
F src/test_devsym.c 6012cb8e3acf812513511025a4fa5d626e0ba19b
-F src/test_func.c ade4f0117cc96c5a05682e1ef38b84320a866ad9
+F src/test_func.c 24a556989685495013e08f311ae31c4ef86ddb8c
F src/test_hexio.c 2f1122aa3f012fa0142ee3c36ce5c902a70cd12f
F src/test_loadext.c df8ab3a6481ddebbdf0d28ebac5d9e0790f7860f
F src/test_malloc.c e655e3ff61845fc23886ee81973638e795477c9e
@@ -181,11 +181,11 @@
F src/utf.c 8d52f620a7153d90b058502124fe51d821fcdf57
F src/util.c a8f80412a536ea309c1887e5d4b58a3fa6eca69c
F src/vacuum.c ef342828002debc97514617af3424aea8ef8522c
-F src/vdbe.c 14d98d1d47041a99a9c98034842772dbbcc062fb
+F src/vdbe.c 179dbe5f08b17c712be65e951eaada3b3ca52092
F src/vdbe.h c46155c221418bea29ee3a749d5950fcf85a70e2
F src/vdbeInt.h 30535c1d30ba1b5fb58d8f0e1d1261af976558aa
F src/vdbeapi.c a7c6b8db324cf7eccff32de871dea36aa305c994
-F src/vdbeaux.c 24ecae4e3e7ebcfb604d6ef0dc268da2cfb3ffa7
+F src/vdbeaux.c 25d562cda55cb6d9796110ee916a524bdd03a0fb
F src/vdbeblob.c a20fe9345062b1a1b4cc187dc5fad45c9414033b
F src/vdbefifo.c c46dae1194e4277bf007144d7e5b0c0b1c24f136
F src/vdbemem.c 0c72b58ffd759676ce4829f42bacb83842a58c21
@@ -274,6 +274,7 @@
F test/enc.test e54531cd6bf941ee6760be041dff19a104c7acea
F test/enc2.test 6d91a5286f59add0cfcbb2d0da913b76f2242398
F test/enc3.test 5c550d59ff31dccdba5d1a02ae11c7047d77c041
+F test/eval.test 020a21a236667bd4c56205d999c9992f1d944cac
F test/exclusive.test 5390ddf1f90a6d055111c0ebe6311045dd3035e1
F test/exclusive2.test d13bf66753dca46e61241d35d36ab7c868b0d313
F test/exec.test e949714dc127eaa5ecc7d723efec1ec27118fdd7
@@ -604,7 +605,7 @@
F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
F tool/speedtest8.c 1dbced29de5f59ba2ebf877edcadf171540374d1
F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P 6dcce6b9748c6148a768a4f6b69f33f70edc3993
-R 0792731ecd027d8cdcf662cd0517070f
+P 1041deb6ae03c52ce1fb8170d11913cc0bbf3a6e
+R 14bde473a1bc0347c0884dfdfef2d004
U drh
-Z 9e913ba85dc9c52696a07ed2d3591212
+Z 356e23cc4752d813c3f7c25ef3dd2a11
diff --git a/manifest.uuid b/manifest.uuid
index abad8dd..2b5b8f9 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-1041deb6ae03c52ce1fb8170d11913cc0bbf3a6e
\ No newline at end of file
+c80a5d09935c60a2a50bc262c172a94073355f0d
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index 8ef51f5..cf531b9 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -9,7 +9,7 @@
** May you share freely, never taking more than you give.
**
*************************************************************************
-** $Id: btree.c,v 1.480 2008/07/11 16:39:23 drh Exp $
+** $Id: btree.c,v 1.481 2008/07/11 21:02:54 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
@@ -361,14 +361,10 @@
** Restore the cursor to the position it was in (or as close to as possible)
** when saveCursorPosition() was called. Note that this call deletes the
** saved position info stored by saveCursorPosition(), so there can be
-** at most one effective restoreOrClearCursorPosition() call after each
+** at most one effective restoreCursorPosition() call after each
** saveCursorPosition().
-**
-** If the second argument argument - doSeek - is false, then instead of
-** returning the cursor to its saved position, any saved position is deleted
-** and the cursor state set to CURSOR_INVALID.
*/
-int sqlite3BtreeRestoreOrClearCursorPosition(BtCursor *pCur){
+int sqlite3BtreeRestoreCursorPosition(BtCursor *pCur){
int rc;
assert( cursorHoldsMutex(pCur) );
assert( pCur->eState>=CURSOR_REQUIRESEEK );
@@ -385,11 +381,35 @@
return rc;
}
-#define restoreOrClearCursorPosition(p) \
+#define restoreCursorPosition(p) \
(p->eState>=CURSOR_REQUIRESEEK ? \
- sqlite3BtreeRestoreOrClearCursorPosition(p) : \
+ sqlite3BtreeRestoreCursorPosition(p) : \
SQLITE_OK)
+/*
+** Determine whether or not a cursor has moved from the position it
+** was last placed at. Cursor can move when the row they are pointing
+** at is deleted out from under them.
+**
+** This routine returns an error code if something goes wrong. The
+** integer *pHasMoved is set to one if the cursor has moved and 0 if not.
+*/
+int sqlite3BtreeCursorHasMoved(BtCursor *pCur, int *pHasMoved){
+ int rc;
+
+ rc = restoreCursorPosition(pCur);
+ if( rc ){
+ *pHasMoved = 1;
+ return rc;
+ }
+ if( pCur->eState!=CURSOR_VALID || pCur->skip!=0 ){
+ *pHasMoved = 1;
+ }else{
+ *pHasMoved = 0;
+ }
+ return SQLITE_OK;
+}
+
#ifndef SQLITE_OMIT_AUTOVACUUM
/*
** Given a page number of a regular database page, return the page
@@ -2768,9 +2788,7 @@
return SQLITE_OK;
create_cursor_exception:
- if( pCur ){
- releasePage(pCur->pPage);
- }
+ releasePage(pCur->pPage);
unlockBtreeIfUnused(pBt);
return rc;
}
@@ -2905,7 +2923,7 @@
int rc;
assert( cursorHoldsMutex(pCur) );
- rc = restoreOrClearCursorPosition(pCur);
+ rc = restoreCursorPosition(pCur);
if( rc==SQLITE_OK ){
assert( pCur->eState==CURSOR_INVALID || pCur->eState==CURSOR_VALID );
if( pCur->eState==CURSOR_INVALID ){
@@ -2929,7 +2947,7 @@
int rc;
assert( cursorHoldsMutex(pCur) );
- rc = restoreOrClearCursorPosition(pCur);
+ rc = restoreCursorPosition(pCur);
if( rc==SQLITE_OK ){
assert( pCur->eState==CURSOR_INVALID || pCur->eState==CURSOR_VALID );
if( pCur->eState==CURSOR_INVALID ){
@@ -3237,7 +3255,7 @@
int rc;
assert( cursorHoldsMutex(pCur) );
- rc = restoreOrClearCursorPosition(pCur);
+ rc = restoreCursorPosition(pCur);
if( rc==SQLITE_OK ){
assert( pCur->eState==CURSOR_VALID );
assert( pCur->pPage!=0 );
@@ -3270,7 +3288,7 @@
#endif
assert( cursorHoldsMutex(pCur) );
- rc = restoreOrClearCursorPosition(pCur);
+ rc = restoreCursorPosition(pCur);
if( rc==SQLITE_OK ){
assert( pCur->eState==CURSOR_VALID );
assert( pCur->pPage!=0 );
@@ -3821,7 +3839,7 @@
MemPage *pPage;
assert( cursorHoldsMutex(pCur) );
- rc = restoreOrClearCursorPosition(pCur);
+ rc = restoreCursorPosition(pCur);
if( rc!=SQLITE_OK ){
return rc;
}
@@ -3890,7 +3908,7 @@
MemPage *pPage;
assert( cursorHoldsMutex(pCur) );
- rc = restoreOrClearCursorPosition(pCur);
+ rc = restoreCursorPosition(pCur);
if( rc!=SQLITE_OK ){
return rc;
}
@@ -5834,7 +5852,7 @@
** that the entry will be deleted from.
*/
if(
- (rc = restoreOrClearCursorPosition(pCur))!=0 ||
+ (rc = restoreCursorPosition(pCur))!=0 ||
(rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur))!=0 ||
(rc = sqlite3PagerWrite(pPage->pDbPage))!=0
){
@@ -6362,10 +6380,10 @@
*/
int sqlite3BtreeFlags(BtCursor *pCur){
/* TODO: What about CURSOR_REQUIRESEEK state? Probably need to call
- ** restoreOrClearCursorPosition() here.
+ ** restoreCursorPosition() here.
*/
MemPage *pPage;
- restoreOrClearCursorPosition(pCur);
+ restoreCursorPosition(pCur);
pPage = pCur->pPage;
assert( cursorHoldsMutex(pCur) );
assert( pPage->pBt==pCur->pBt );
@@ -7176,7 +7194,7 @@
assert( sqlite3_mutex_held(pCsr->pBtree->db->mutex) );
assert(pCsr->isIncrblobHandle);
- restoreOrClearCursorPosition(pCsr);
+ restoreCursorPosition(pCsr);
assert( pCsr->eState!=CURSOR_REQUIRESEEK );
if( pCsr->eState!=CURSOR_VALID ){
return SQLITE_ABORT;
diff --git a/src/btree.h b/src/btree.h
index 780f1d3..3fe01cb 100644
--- a/src/btree.h
+++ b/src/btree.h
@@ -13,7 +13,7 @@
** subsystem. See comments in the source code for a detailed description
** of what each interface routine does.
**
-** @(#) $Id: btree.h,v 1.101 2008/07/11 16:15:18 drh Exp $
+** @(#) $Id: btree.h,v 1.102 2008/07/11 21:02:54 drh Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_
@@ -142,6 +142,7 @@
int bias,
int *pRes
);
+int sqlite3BtreeCursorHasMoved(BtCursor*, int*);
int sqlite3BtreeDelete(BtCursor*);
int sqlite3BtreeInsert(BtCursor*, const void *pKey, i64 nKey,
const void *pData, int nData,
diff --git a/src/btreeInt.h b/src/btreeInt.h
index 0ec07aa..2fd4235 100644
--- a/src/btreeInt.h
+++ b/src/btreeInt.h
@@ -9,7 +9,7 @@
** May you share freely, never taking more than you give.
**
*************************************************************************
-** $Id: btreeInt.h,v 1.24 2008/07/10 00:32:42 drh Exp $
+** $Id: btreeInt.h,v 1.25 2008/07/11 21:02:54 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
@@ -466,7 +466,7 @@
** The table that this cursor was opened on still exists, but has been
** modified since the cursor was last used. The cursor position is saved
** in variables BtCursor.pKey and BtCursor.nKey. When a cursor is in
-** this state, restoreOrClearCursorPosition() can be called to attempt to
+** this state, restoreCursorPosition() can be called to attempt to
** seek the cursor to the saved position.
**
** CURSOR_FAULT:
@@ -631,7 +631,7 @@
int sqlite3BtreeInitPage(MemPage *pPage, MemPage *pParent);
void sqlite3BtreeParseCellPtr(MemPage*, u8*, CellInfo*);
void sqlite3BtreeParseCell(MemPage*, int, CellInfo*);
-int sqlite3BtreeRestoreOrClearCursorPosition(BtCursor *pCur);
+int sqlite3BtreeRestoreCursorPosition(BtCursor *pCur);
void sqlite3BtreeGetTempCursor(BtCursor *pCur, BtCursor *pTempCur);
void sqlite3BtreeReleaseTempCursor(BtCursor *pCur);
int sqlite3BtreeIsRootPage(MemPage *pPage);
diff --git a/src/select.c b/src/select.c
index e14e292..56ede61 100644
--- a/src/select.c
+++ b/src/select.c
@@ -12,7 +12,7 @@
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
-** $Id: select.c,v 1.454 2008/07/10 17:59:12 danielk1977 Exp $
+** $Id: select.c,v 1.455 2008/07/11 21:02:54 drh Exp $
*/
#include "sqliteInt.h"
@@ -1165,7 +1165,7 @@
assert( pTab->nCol>0 );
pTab->aCol = aCol = sqlite3DbMallocZero(db, sizeof(pTab->aCol[0])*pTab->nCol);
for(i=0, pCol=aCol; i<pTab->nCol; i++, pCol++){
- Expr *p, *pR;
+ Expr *p;
char *zType;
char *zName;
int nName;
diff --git a/src/test_btree.c b/src/test_btree.c
index 615c960..1b33ef9 100644
--- a/src/test_btree.c
+++ b/src/test_btree.c
@@ -13,7 +13,7 @@
** is not included in the SQLite library. It is used for automated
** testing of the SQLite library.
**
-** $Id: test_btree.c,v 1.4 2008/07/10 00:32:42 drh Exp $
+** $Id: test_btree.c,v 1.5 2008/07/11 21:02:54 drh Exp $
*/
#include "btreeInt.h"
#include <tcl.h>
@@ -87,7 +87,7 @@
int rc;
if( pCur->eState==CURSOR_REQUIRESEEK ){
- rc = sqlite3BtreeRestoreOrClearCursorPosition(pCur);
+ rc = sqlite3BtreeRestoreCursorPosition(pCur);
if( rc!=SQLITE_OK ){
return rc;
}
diff --git a/src/test_func.c b/src/test_func.c
index 3704552..d43b7a9 100644
--- a/src/test_func.c
+++ b/src/test_func.c
@@ -12,7 +12,7 @@
** Code for testing all sorts of SQLite interfaces. This code
** implements new SQL functions used by the test scripts.
**
-** $Id: test_func.c,v 1.7 2008/07/08 14:17:35 danielk1977 Exp $
+** $Id: test_func.c,v 1.8 2008/07/11 21:02:54 drh Exp $
*/
#include "sqlite3.h"
#include "tcl.h"
@@ -230,6 +230,38 @@
sqlite3_result_value(pCtx, argv[1]);
}
+/*
+** Invoke an SQL statement recursively. The function result is the
+** first column of the first row of the result set.
+*/
+static void test_eval(
+ sqlite3_context *pCtx,
+ int nArg,
+ sqlite3_value **argv
+){
+ sqlite3_stmt *pStmt;
+ int rc;
+ sqlite3 *db = sqlite3_context_db_handle(pCtx);
+ const char *zSql;
+
+ zSql = (char*)sqlite3_value_text(argv[0]);
+ rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+ if( rc==SQLITE_OK ){
+ rc = sqlite3_step(pStmt);
+ if( rc==SQLITE_ROW ){
+ sqlite3_result_value(pCtx, sqlite3_column_value(pStmt, 0));
+ }
+ rc = sqlite3_finalize(pStmt);
+ }
+ if( rc ){
+ char *zErr;
+ assert( pStmt==0 );
+ zErr = sqlite3_mprintf("sqlite3_prepare_v2() error: %s",sqlite3_errmsg(db));
+ sqlite3_result_text(pCtx, zErr, -1, sqlite3_free);
+ sqlite3_result_error_code(pCtx, rc);
+ }
+}
+
static int registerTestFunctions(sqlite3 *db){
static const struct {
@@ -245,6 +277,7 @@
{ "test_auxdata", -1, SQLITE_UTF8, test_auxdata},
{ "test_error", 1, SQLITE_UTF8, test_error},
{ "test_error", 2, SQLITE_UTF8, test_error},
+ { "test_eval", 1, SQLITE_UTF8, test_eval},
{ "test_isolation", 2, SQLITE_UTF8, test_isolation},
};
int i;
diff --git a/src/vdbe.c b/src/vdbe.c
index ac3e208..d65995b 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -43,7 +43,7 @@
** in this file for details. If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
-** $Id: vdbe.c,v 1.760 2008/07/10 00:32:42 drh Exp $
+** $Id: vdbe.c,v 1.761 2008/07/11 21:02:54 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -1670,7 +1670,6 @@
int flags;
int res;
char affinity;
- Mem x1, x3;
flags = pIn1->flags|pIn3->flags;
@@ -3808,6 +3807,7 @@
case OP_Next: { /* jump */
Cursor *pC;
BtCursor *pCrsr;
+ int res;
CHECK_FOR_INTERRUPT;
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
@@ -3817,19 +3817,17 @@
}
pCrsr = pC->pCursor;
assert( pCrsr );
- if( pC->nullRow==0 ){
- int res = 1;
- assert( pC->deferredMoveto==0 );
- rc = pOp->opcode==OP_Next ? sqlite3BtreeNext(pCrsr, &res) :
- sqlite3BtreePrevious(pCrsr, &res);
- pC->nullRow = res;
- pC->cacheStatus = CACHE_STALE;
- if( res==0 ){
- pc = pOp->p2 - 1;
+ res = 1;
+ assert( pC->deferredMoveto==0 );
+ rc = pOp->opcode==OP_Next ? sqlite3BtreeNext(pCrsr, &res) :
+ sqlite3BtreePrevious(pCrsr, &res);
+ pC->nullRow = res;
+ pC->cacheStatus = CACHE_STALE;
+ if( res==0 ){
+ pc = pOp->p2 - 1;
#ifdef SQLITE_TEST
- sqlite3_search_count++;
+ sqlite3_search_count++;
#endif
- }
}
pC->rowidIsValid = 0;
break;
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index 6e61ce4..79fe89f 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -14,7 +14,7 @@
** to version 2.8.7, all this code was combined into the vdbe.c source file.
** But that file was getting too big so this subroutines were split out.
**
-** $Id: vdbeaux.c,v 1.396 2008/07/11 16:15:18 drh Exp $
+** $Id: vdbeaux.c,v 1.397 2008/07/11 21:02:54 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -1864,6 +1864,14 @@
#endif
p->deferredMoveto = 0;
p->cacheStatus = CACHE_STALE;
+ }else if( p->pCursor ){
+ int hasMoved;
+ int rc = sqlite3BtreeCursorHasMoved(p->pCursor, &hasMoved);
+ if( rc ) return rc;
+ if( hasMoved ){
+ p->cacheStatus = CACHE_STALE;
+ p->nullRow = 1;
+ }
}
return SQLITE_OK;
}
diff --git a/test/eval.test b/test/eval.test
new file mode 100644
index 0000000..0f51b22
--- /dev/null
+++ b/test/eval.test
@@ -0,0 +1,71 @@
+# 2008 July 11
+#
+# 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.
+#
+# This file experiments with recursion using the "test_eval()" SQL function
+# in order to make sure that SQLite is reentrant.
+#
+# $Id: eval.test,v 1.1 2008/07/11 21:02:54 drh Exp $
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+# Create a table to work with.
+#
+do_test eval-1.1 {
+ execsql {
+ CREATE TABLE t1(x INTEGER PRIMARY KEY);
+ INSERT INTO t1 VALUES(1);
+ INSERT INTO t1 VALUES(2);
+ INSERT INTO t1 SELECT x+2 FROM t1;
+ INSERT INTO t1 SELECT x+4 FROM t1;
+ INSERT INTO t1 SELECT x+8 FROM t1;
+ INSERT INTO t1 SELECT x+16 FROM t1;
+ INSERT INTO t1 SELECT x+32 FROM t1;
+ INSERT INTO t1 SELECT x+64 FROM t1;
+ INSERT INTO t1 SELECT x+128 FROM t1;
+ INSERT INTO t1 SELECT x+256 FROM t1;
+ SELECT count(*), max(x) FROM t1;
+ }
+} {512 512}
+do_test eval-1.2 {
+ execsql {
+ SELECT x, test_eval('SELECT max(x) FROM t1 WHERE x<' || x) FROM t1 LIMIT 5
+ }
+} {1 {} 2 1 3 2 4 3 5 4}
+
+# Delete a row out from under a read cursor in the middle of
+# collecting the arguments for a single row in a result set.
+# Verify that subsequent rows come out as NULL.
+#
+do_test eval-2.1 {
+ execsql {
+ CREATE TABLE t2(x,y);
+ INSERT INTO t2 SELECT x, x+1 FROM t1 WHERE x<5;
+ SELECT x, test_eval('DELETE FROM t2 WHERE x='||x), y FROM t2;
+ }
+} {1 {} {} 2 {} {} 3 {} {} 4 {} {}}
+do_test eval-2.2 {
+ execsql {
+ SELECT * FROM t2
+ }
+} {}
+
+# Modify a row while it is being read.
+#
+do_test eval-3.1 {
+ execsql {
+ INSERT INTO t2 SELECT x, x+1 FROM t1 WHERE x<5;
+ SELECT x, test_eval('UPDATE t2 SET y=y+100 WHERE x='||x), y FROM t2;
+ }
+} {1 {} 102 2 {} 103 3 {} 104 4 {} 105}
+
+finish_test