Avoid an infinite loop that could be entered when dealing with corrupt fts5 tombstone hash pages.

FossilOrigin-Name: 69ce2ce035279f2a00c2238187cf4d2a9092c3410f5900e4613fe4e46311169e

ext/fts5/fts5_index.c

@@ -3109,9 +3109,10 @@ static int fts5IndexTombstoneQuery(
   int nHashTable,                 /* Number of pages attached to segment */
   u64 iRowid                      /* Rowid to query hash for */
 ){
-  int szKey = TOMBSTONE_KEYSIZE(pHash);
-  int nSlot = (pHash->nn - 8) / szKey;
+  const int szKey = TOMBSTONE_KEYSIZE(pHash);
+  const int nSlot = (pHash->nn - 8) / szKey;
   int iSlot = (iRowid / nHashTable) % nSlot;
+  int nCollide = nSlot;
 
   if( iRowid==0 ){
     return pHash->p[1];
@@ -3119,12 +3120,14 @@ static int fts5IndexTombstoneQuery(
     u32 *aSlot = (u32*)&pHash->p[8];
     while( aSlot[iSlot] ){
       if( fts5GetU32((u8*)&aSlot[iSlot])==iRowid ) return 1;
+      if( nCollide--==0 ) break;
       iSlot = (iSlot+1)%nSlot;
     }
   }else{
     u64 *aSlot = (u64*)&pHash->p[8];
     while( aSlot[iSlot] ){
       if( fts5GetU64((u8*)&aSlot[iSlot])==iRowid ) return 1;
+      if( nCollide--==0 ) break;
       iSlot = (iSlot+1)%nSlot;
     }
   }
@@ -6550,10 +6553,11 @@ static int fts5IndexTombstoneAddToPage(
   int nPg, 
   u64 iRowid
 ){
-  int szKey = TOMBSTONE_KEYSIZE(pPg);
-  int nSlot = (pPg->nn - 8) / szKey;
+  const int szKey = TOMBSTONE_KEYSIZE(pPg);
+  const int nSlot = (pPg->nn - 8) / szKey;
+  const int nElem = fts5GetU32(&pPg->p[4]);
   int iSlot = (iRowid / nPg) % nSlot;
-  int nElem = fts5GetU32(&pPg->p[4]);
+  int nCollide = nSlot;
 
   if( szKey==4 && iRowid>0xFFFFFFFF ) return 2;
   if( iRowid==0 ){
@@ -6568,11 +6572,17 @@ static int fts5IndexTombstoneAddToPage(
   fts5PutU32(&pPg->p[4], nElem+1);
   if( szKey==4 ){
     u32 *aSlot = (u32*)&pPg->p[8];
-    while( aSlot[iSlot] ) iSlot = (iSlot + 1) % nSlot;
+    while( aSlot[iSlot] ){
+      iSlot = (iSlot + 1) % nSlot;
+      if( nCollide--==0 ) return 0;
+    }
     fts5PutU32((u8*)&aSlot[iSlot], (u32)iRowid);
   }else{
     u64 *aSlot = (u64*)&pPg->p[8];
-    while( aSlot[iSlot] ) iSlot = (iSlot + 1) % nSlot;
+    while( aSlot[iSlot] ){
+      iSlot = (iSlot + 1) % nSlot;
+      if( nCollide--==0 ) return 0;
+    }
     fts5PutU64((u8*)&aSlot[iSlot], iRowid);
   }
 

ext/fts5/test/fts5contentless3.test

@@ -0,0 +1,76 @@
+# 2023 July 21
+#
+# 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 contains tests for the content= and content_rowid= options.
+#
+
+source [file join [file dirname [info script]] fts5_common.tcl]
+set testprefix fts5contentless3
+
+# If SQLITE_ENABLE_FTS5 is defined, omit this file.
+ifcapable !fts5 {
+  finish_test
+  return
+}
+
+do_execsql_test 1.0 {
+  CREATE VIRTUAL TABLE ft USING fts5(x, content=, contentless_delete=1);
+  BEGIN;
+    INSERT INTO ft VALUES('one one one');
+    INSERT INTO ft VALUES('two two two');
+    INSERT INTO ft VALUES('three three three');
+    INSERT INTO ft VALUES('four four four');
+    INSERT INTO ft VALUES('five five five');
+  COMMIT;
+
+  DELETE FROM ft WHERE rowid=3;
+}
+
+proc myhex {hex} { binary decode hex $hex }
+db func myhex myhex
+
+do_execsql_test 1.1 {
+  UPDATE ft_data SET block = 
+    myhex('04000000 00000001'                   ||
+          '01020304 01020304 01020304 01020304' ||
+          '01020304 01020304 01020304 01020304'
+    )
+  WHERE id = (SELECT max(id) FROM ft_data);
+}
+
+do_execsql_test 1.2 {
+  DELETE FROM ft WHERE rowid=1
+}
+
+do_execsql_test 1.3 {
+  SELECT rowid FROM ft('two');
+} {2}
+
+do_execsql_test 1.3 {
+  UPDATE ft_data SET block = 
+    myhex('08000000 00000001'                                               ||
+      '0000000001020304 0000000001020304 0000000001020304 0000000001020304' ||
+      '0000000001020304 0000000001020304 0000000001020304 0000000001020304'
+    )
+  WHERE id = (SELECT max(id) FROM ft_data);
+}
+
+do_execsql_test 1.4 {
+  SELECT rowid FROM ft('two');
+} {2}
+
+do_execsql_test 1.5 {
+  DELETE FROM ft WHERE rowid=4
+}
+
+
+finish_test
+

manifest

@@ -1,5 +1,5 @@
-C Add\stests\sand\sfixes\sfor\sthe\snew\scode\son\sthis\sbranch.
-D 2023-07-20T16:07:04.821
+C Avoid\san\sinfinite\sloop\sthat\scould\sbe\sentered\swhen\sdealing\swith\scorrupt\sfts5\stombstone\shash\spages.
+D 2023-07-20T20:09:26.394
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -92,7 +92,7 @@ F ext/fts5/fts5_buffer.c 3001fbabb585d6de52947b44b455235072b741038391f830d6b7292
 F ext/fts5/fts5_config.c 010fabcc0aaa0dfa76b19146e8bddf7de368933eeac01e294af6607447500caa
 F ext/fts5/fts5_expr.c 2473c13542f463cae4b938c498d6193c90d38ea1a2a4f9849c0479736e50d24d
 F ext/fts5/fts5_hash.c d4fb70940359f2120ccd1de7ffe64cc3efe65de9e8995b822cd536ff64c96982
-F ext/fts5/fts5_index.c 69d44e0358de3db791165c1accbbabcb0e41b7942b12d644f3d515c9a5434386
+F ext/fts5/fts5_index.c 5b5b9944ef97bf9aa0726fdbd82552d488b6fcee32e086e6d32ea9934e1809e2
 F ext/fts5/fts5_main.c ede405f0f11db562653b988d043a531daa66093b46c1b35b8fcddb54819cba84
 F ext/fts5/fts5_storage.c 3c9b41fce41b6410f2e8f82eb035c6a29b2560483f773e6dc98cf3cb2e4ddbb5
 F ext/fts5/fts5_tcl.c b1445cbe69908c411df8084a10b2485500ac70a9c747cdc8cda175a3da59d8ae
@@ -134,6 +134,7 @@ F ext/fts5/test/fts5connect.test 08030168fc96fc278fa81f28654fb7e90566f33aff269c0
 F ext/fts5/test/fts5content.test 213506436fb2c87567b8e31f6d43ab30aab99354cec74ed679f22aad0cdbf283
 F ext/fts5/test/fts5contentless.test 9a42a86822670792ba632f5c57459addeb774d93b29d5e6ddae08faa64c2b6d9
 F ext/fts5/test/fts5contentless2.test 12c778d134a121b8bad000fbf3ae900d53226fee840ce36fe941b92737f1fda7
+F ext/fts5/test/fts5contentless3.test db92625a2e3f9e5ba047ce8ded58c825affce45cc711ed6d7c96fe54b95894a1
 F ext/fts5/test/fts5corrupt.test 77ae6f41a7eba10620efb921cf7dbe218b0ef232b04519deb43581cb17a57ebe
 F ext/fts5/test/fts5corrupt2.test 7453752ba12ce91690c469a6449d412561cc604b1dec994e16ab132952e7805f
 F ext/fts5/test/fts5corrupt3.test 7da9895dafa404efd20728f66ff4b94399788bdc042c36fe2689801bba2ccd78
@@ -2046,8 +2047,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 8d09011fa2c6ae9cc88e1766f9aad4578efbf9e0e311b8c6efdffe7a3f88f923
-R 8705dc9e0fc623331a29c540c6694db8
+P 5aac50e92e956b15367c75c20c17bc1c75e84e2752bfffe4ad0a266cb9bd3b8a
+R a2bc7a639e489f4200810e70aeab413a
 U dan
-Z 5d09d15bf916dffd1a9ed46964991145
+Z 36cb6c12a15fce5364a14d77012ed267
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-5aac50e92e956b15367c75c20c17bc1c75e84e2752bfffe4ad0a266cb9bd3b8a
+69ce2ce035279f2a00c2238187cf4d2a9092c3410f5900e4613fe4e46311169e