From: drh <>
Date: Fri, 12 Apr 2024 12:32:09 +0000 (+0000)
Subject: New assert() statements to verify the correctness of the BTCF_AtLast flag
X-Git-Tag: version-3.46.0~66^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ae7ede4a4f70648170b05d176b877f97734d1383;p=thirdparty%2Fsqlite.git

New assert() statements to verify the correctness of the BTCF_AtLast flag
on btree cursors.

FossilOrigin-Name: 4efecd6167de71500c90b63155eba1b8567c90e9d1e282fbea54130f9ee21813
---

diff --git a/manifest b/manifest
index 3d880dd346..070fa270cd 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Test\scase\sfor\sthe\sfix\sin\sthe\sprevious\scheck-in.
-D 2024-04-12T11:28:35.112
+C New\sassert()\sstatements\sto\sverify\sthe\scorrectness\sof\sthe\sBTCF_AtLast\sflag\non\sbtree\scursors.
+D 2024-04-12T12:32:09.806
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -689,7 +689,7 @@ F src/auth.c 19b7ccacae3dfba23fc6f1d0af68134fa216e9040e53b0681b4715445ea030b4
 F src/backup.c 5c97e8023aab1ce14a42387eb3ae00ba5a0644569e3476f38661fa6f824c3523
 F src/bitvec.c 9eac5f42c11914d5ef00a75605bb205e934f435c579687f985f1f8b0995c8645
 F src/btmutex.c 79a43670447eacc651519a429f6ece9fd638563cf95b469d6891185ddae2b522
-F src/btree.c a654c4b4d84821f4fdeb322df185317493be30c1b114cb75d56adb50dd3f661c
+F src/btree.c b489280734e3c085774ecc86a07f5ad5b805d86e2cb28650c3b3e141673993d6
 F src/btree.h 55066f513eb095db935169dab1dc2f7c7a747ef223c533f5d4ad4dfed346cbd0
 F src/btreeInt.h 98aadb6dcb77b012cab2574d6a728fad56b337fc946839b9898c4b4c969e30b6
 F src/build.c 02f5b25ca854c83b5015cb02b8c9ab236c60b1795528675aee8a5070e58da52a
@@ -2184,8 +2184,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 74c9e19c92c887012aebbe96450f6ed7a60ba22d6e3edbaa39a0f989fb7f2901
-R e5ebeec2e7c87917a5e915be853b1124
+P 0cf4d835dae260b01178e94e77be6b8a130f2031e898ef79ceba8df6c2bba58f
+R 3352218b957f71135e62b28b93e477b6
 U drh
-Z 367db0044284a550a3cf0e6c6563bd86
+Z 55f6b761ddb19ac9081b9562cfbe54ea
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 3a012e5380..01cbdd4cd6 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-0cf4d835dae260b01178e94e77be6b8a130f2031e898ef79ceba8df6c2bba58f
\ No newline at end of file
+4efecd6167de71500c90b63155eba1b8567c90e9d1e282fbea54130f9ee21813
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index e957ccb199..91c9e4fb57 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -5624,6 +5624,23 @@ int sqlite3BtreeFirst(BtCursor *pCur, int *pRes){
   return rc;
 }
 
+#ifdef SQLITE_DEBUG
+/* The cursors is CURSOR_VALID and has BTCF_AtLast set.  Verify that
+** this flags are true for a consistent database.
+**
+** This routine is is called from within assert() statements only.
+** It is an internal verification routine and does not appear in production
+** builds.
+*/
+static int cursorIsAtLastEntry(BtCursor *pCur){
+  int ii;
+  for(ii=0; ii<pCur->iPage; ii++){
+    if( pCur->aiIdx[ii]!=pCur->apPage[ii]->nCell ) return 0;
+  }
+  return pCur->ix==pCur->pPage->nCell-1 && pCur->pPage->leaf!=0;
+}
+#endif
+
 /* Move the cursor to the last entry in the table.  Return SQLITE_OK
 ** on success.  Set *pRes to 0 if the cursor actually points to something
 ** or set *pRes to 1 if the table is empty.
@@ -5652,18 +5669,7 @@ int sqlite3BtreeLast(BtCursor *pCur, int *pRes){
 
   /* If the cursor already points to the last entry, this is a no-op. */
   if( CURSOR_VALID==pCur->eState && (pCur->curFlags & BTCF_AtLast)!=0 ){
-#ifdef SQLITE_DEBUG
-    /* This block serves to assert() that the cursor really does point
-    ** to the last entry in the b-tree. */
-    int ii;
-    for(ii=0; ii<pCur->iPage; ii++){
-      assert( pCur->aiIdx[ii]==pCur->apPage[ii]->nCell );
-    }
-    assert( pCur->ix==pCur->pPage->nCell-1 || CORRUPT_DB );
-    testcase( pCur->ix!=pCur->pPage->nCell-1 );
-    /* ^-- dbsqlfuzz b92b72e4de80b5140c30ab71372ca719b8feb618 */
-    assert( pCur->pPage->leaf );
-#endif
+    assert( cursorIsAtLastEntry(pCur) || CORRUPT_DB );
     *pRes = 0;
     return SQLITE_OK;
   }
@@ -5716,6 +5722,7 @@ int sqlite3BtreeTableMoveto(
     }
     if( pCur->info.nKey<intKey ){
       if( (pCur->curFlags & BTCF_AtLast)!=0 ){
+        assert( cursorIsAtLastEntry(pCur) || CORRUPT_DB );
         *pRes = -1;
         return SQLITE_OK;
       }