Make sure the sqlite3BtreePrevious() routine terminates properly if the

table is deleted out from under it.  Ticket #2286.  This bug was discovered
while trying to increase test coverage from 98.5% to 99% - once again
showing the value of full coverage testing. (CVS 3818)

FossilOrigin-Name: bebf8d2f886ed9fe1b96e4cb11ab3de2f2f7d2c8

manifest

@@ -1,5 +1,5 @@
-C Fix\sthe\samalgamation\sso\sthat\sit\sworks\swith\s-DSQLITE_ENABLE_REDEF_IO.\s\sChange\ntclsqlite.c\sso\sthat\sit\scan\sbe\sappended\sto\sthe\samalgamation.\s\sCreate\sa\snew\namalgamation\sof\sheader\sfiles\sfor\suse\sby\sprojects\sthat\swant\sto\sredefine\stheir\nown\sI/O\sinterface\susing\s-DSQLITE_ENABLE_REDEF_IO.\s(CVS\s3817)
+C Make\ssure\sthe\ssqlite3BtreePrevious()\sroutine\sterminates\sproperly\sif\sthe\ntable\sis\sdeleted\sout\sfrom\sunder\sit.\s\sTicket\s#2286.\s\sThis\sbug\swas\sdiscovered\nwhile\strying\sto\sincrease\stest\scoverage\sfrom\s98.5%\sto\s99%\s-\sonce\sagain\nshowing\sthe\svalue\sof\sfull\scoverage\stesting.\s(CVS\s3818)
-D 2007-04-05T21:58:33
+D 2007-04-06T01:03:33
 F Makefile.in a9bd493360a2b17e5214b69d8c32dd6cdaceaf55
 F Makefile.linux-gcc 2d8574d1ba75f129aba2019f0b959db380a90935
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -58,7 +58,7 @@ F src/alter.c 2c79ec40f65e33deaf90ca493422c74586e481a3
 F src/analyze.c 4bbf5ddf9680587c6d4917e02e378b6037be3651
 F src/attach.c a16ada4a4654a0d126b8223ec9494ebb81bc5c3c
 F src/auth.c 902f4722661c796b97f007d9606bd7529c02597f
-F src/btree.c 48fa58f2d71edeab4a7d08157abe50a0b7a0e489
+F src/btree.c 27299eba3ad5aa1fed184c707576d12d0e608e8d
 F src/btree.h 9b2cc0d113c0bc2d37d244b9a394d56948c9acbf
 F src/build.c 7c2efa468f0c404ef5aa648d43c383318390937f
 F src/callback.c 31d22b4919c7645cbcbb1591ce2453e8c677c558
@@ -271,7 +271,7 @@ F test/memdb.test a67bda4ff90a38f2b19f6c7f95aa7289e051d893
 F test/memleak.test d2d2a1ff7105d32dc3fdf691458cf6cba58c7217
 F test/minmax.test 66434d8ee04869fe4c220b665b73748accbb9163
 F test/misc1.test 27a6ad11ba6e4b73aeee650ab68053ad7dfd0433
-F test/misc2.test 0b45deedcfd6ba857ea2f377c5669d3501a535c7
+F test/misc2.test d35faf7df27750d25ab656ca92dceebbd89f7368
 F test/misc3.test 7bd937e2c62bcc6be71939faf068d506467b1e03
 F test/misc4.test b043a05dea037cca5989f3ae09552fa16119bc80
 F test/misc5.test c7d2d2a5a20dc37d3605a8067f0df5af2240122e
@@ -451,7 +451,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513
-P 204e7d38aeb40d126b80a869958ca79cd0902d83
+P f2caff870c81c08ec85aae72986c231ee986b251
-R 33250e136d9f0af3693e864db67d12e7
+R 318b6ff1df8c9d65e7de849f673a3ac5
 U drh
-Z d3104f68e1b1c0abe9a9e14724db1ec1
+Z 3ae24a6bd11cbf91ba2afccd5e139cc3

manifest.uuid

@@ -1 +1 @@
-f2caff870c81c08ec85aae72986c231ee986b251
+bebf8d2f886ed9fe1b96e4cb11ab3de2f2f7d2c8

src/btree.c

@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.350 2007/04/02 05:07:47 danielk1977 Exp $
+** $Id: btree.c,v 1.351 2007/04/06 01:03:33 drh Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** For a detailed discussion of BTrees, refer to
@@ -3520,6 +3520,14 @@ int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
   if( rc!=SQLITE_OK ){
     return rc;
   }
+#endif 
+  assert( pRes!=0 );
+  pPage = pCur->pPage;
+  if( CURSOR_INVALID==pCur->eState ){
+    *pRes = 1;
+    return SQLITE_OK;
+  }
+#ifndef SQLITE_OMIT_SHARED_CACHE
   if( pCur->skip>0 ){
     pCur->skip = 0;
     *pRes = 0;
@@ -3528,12 +3536,6 @@ int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
   pCur->skip = 0;
 #endif 
 
-  assert( pRes!=0 );
-  pPage = pCur->pPage;
-  if( CURSOR_INVALID==pCur->eState ){
-    *pRes = 1;
-    return SQLITE_OK;
-  }
   assert( pPage->isInit );
   assert( pCur->idx<pPage->nCell );
 
@@ -3588,6 +3590,12 @@ int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
   if( rc!=SQLITE_OK ){
     return rc;
   }
+#endif
+  if( CURSOR_INVALID==pCur->eState ){
+    *pRes = 1;
+    return SQLITE_OK;
+  }
+#ifndef SQLITE_OMIT_SHARED_CACHE
   if( pCur->skip<0 ){
     pCur->skip = 0;
     *pRes = 0;
@@ -3596,11 +3604,6 @@ int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
   pCur->skip = 0;
 #endif
 
-  if( CURSOR_INVALID==pCur->eState ){
-    *pRes = 1;
-    return SQLITE_OK;
-  }
-
   pPage = pCur->pPage;
   assert( pPage->isInit );
   assert( pCur->idx>=0 );

test/misc2.test

@@ -13,7 +13,7 @@
 # This file implements tests for miscellanous features that were
 # left out of other test files.
 #
-# $Id: misc2.test,v 1.26 2006/09/29 14:01:07 drh Exp $
+# $Id: misc2.test,v 1.27 2007/04/06 01:03:34 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -253,6 +253,106 @@ do_test misc2-7.8 {
   execsql {SELECT * FROM t1}
 } {1 2 3 4 5 6 7 8 9 10}
 
+# Repeat the tests 7.1 through 7.8 about but this time do the SELECTs
+# in reverse order so that we exercise the sqlite3BtreePrev() routine
+# instead of sqlite3BtreeNext()
+#
+do_test misc2-7.11 {
+  db close
+  file delete -force test.db
+  sqlite3 db test.db
+  execsql {
+    CREATE TABLE t1(x);
+    INSERT INTO t1 VALUES(1);
+    INSERT INTO t1 VALUES(2);
+    INSERT INTO t1 VALUES(3);
+    SELECT * FROM t1;
+  }
+} {1 2 3}
+do_test misc2-7.12 {
+  set rc [catch {
+    db eval {SELECT rowid FROM t1 ORDER BY rowid DESC} {} {
+      db eval "DELETE FROM t1 WHERE rowid=$rowid"
+    }
+  } msg]
+  lappend rc $msg
+} {0 {}}
+do_test misc2-7.13 {
+  execsql {SELECT * FROM t1}
+} {}
+do_test misc2-7.14 {
+  execsql {
+    DELETE FROM t1;
+    INSERT INTO t1 VALUES(1);
+    INSERT INTO t1 VALUES(2);
+    INSERT INTO t1 VALUES(3);
+    INSERT INTO t1 VALUES(4);
+  }
+  db eval {SELECT rowid, x FROM t1 ORDER BY rowid DESC} {
+    if {$x & 1} {
+      db eval {DELETE FROM t1 WHERE rowid=$rowid}
+    }
+  }
+  execsql {SELECT * FROM t1}
+} {2 4}
+do_test misc2-7.15 {
+  execsql {
+    DELETE FROM t1;
+    INSERT INTO t1 VALUES(1);
+    INSERT INTO t1 VALUES(2);
+    INSERT INTO t1 VALUES(3);
+    INSERT INTO t1 VALUES(4);
+  }
+  db eval {SELECT rowid, x FROM t1} {
+    if {$x & 1} {
+      db eval {DELETE FROM t1 WHERE rowid=$rowid+1}
+    }
+  }
+  execsql {SELECT * FROM t1}
+} {1 3}
+do_test misc2-7.16 {
+  execsql {
+    DELETE FROM t1;
+    INSERT INTO t1 VALUES(1);
+    INSERT INTO t1 VALUES(2);
+    INSERT INTO t1 VALUES(3);
+    INSERT INTO t1 VALUES(4);
+  }
+  db eval {SELECT rowid, x FROM t1 ORDER BY rowid DESC} {
+    if {$x & 1} {
+      db eval {DELETE FROM t1}
+    }
+  }
+  execsql {SELECT * FROM t1}
+} {}
+do_test misc2-7.17 {
+  execsql {
+    DELETE FROM t1;
+    INSERT INTO t1 VALUES(1);
+    INSERT INTO t1 VALUES(2);
+    INSERT INTO t1 VALUES(3);
+    INSERT INTO t1 VALUES(4);
+  }
+  db eval {SELECT rowid, x FROM t1 ORDER BY rowid DESC} {
+    if {$x & 1} {
+      db eval {UPDATE t1 SET x=x+100 WHERE rowid=$rowid}
+    }
+  }
+  execsql {SELECT * FROM t1}
+} {101 2 103 4}
+do_test misc2-7.18 {
+  execsql {
+    DELETE FROM t1;
+    INSERT INTO t1(rowid,x) VALUES(10,10);
+  }
+  db eval {SELECT rowid, x FROM t1 ORDER BY rowid DESC} {
+    if {$x>1} {
+      db eval {INSERT INTO t1(rowid,x) VALUES($x-1,$x-1)}
+    }
+  }
+  execsql {SELECT * FROM t1}
+} {1 2 3 4 5 6 7 8 9 10}
+
 db close
 file delete -force test.db
 sqlite3 db test.db