Do not allow an integer overflow to bypass a leaf-term bound check

in the integrity-check function of FTS5.

FossilOrigin-Name: f45d03b1c52ae102eb92b4de21d6a5265831cfd47e51e3193b38d60744c2e0cf

ext/fts5/fts5_index.c

@@ -8540,7 +8540,7 @@ static void fts5IndexIntegrityCheckSegment(
         FTS5_CORRUPT_ROWID(p, iRow);
       }else{
         iOff += fts5GetVarint32(&pLeaf->p[iOff], nTerm);
-        if( iOff+nTerm>pLeaf->szLeaf ){
+        if( (i64)iOff+(i64)nTerm>(i64)pLeaf->szLeaf ){
           FTS5_CORRUPT_ROWID(p, iRow);
         }else{
           res = fts5Memcmp(&pLeaf->p[iOff], zIdxTerm, MIN(nTerm, nIdxTerm));

manifest

@@ -1,5 +1,5 @@
-C Make\ssure\slocal\sfunctions\sin\sthe\sseries.c\sextension\shave\sonly\sfile\sscope.
-D 2026-06-27T21:57:19.338
+C Do\snot\sallow\san\sinteger\soverflow\sto\sbypass\sa\sleaf-term\sbound\scheck\nin\sthe\sintegrity-check\sfunction\sof\sFTS5.
+D 2026-06-27T23:09:49.230
 F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@ -113,7 +113,7 @@ F ext/fts5/fts5_buffer.c dcc3f0352339fe79c9d8abbc1c2009bc3469206467880bf43558447
 F ext/fts5/fts5_config.c bfba970fe1e4eed18ee57c8d51458e226db9a960ddf775c5e50e3d76603a667e
 F ext/fts5/fts5_expr.c b906c59e9e842805cc3eea4e131b822e586bb01260e542f67920c61798dcb53d
 F ext/fts5/fts5_hash.c d5871df92ce3fa210a650cf419ee916b87c29977e86084d06612edf772bff6f5
-F ext/fts5/fts5_index.c c430169e055674d809d89720cde9cef3f18156b353bc67326be8c25de372a89d
+F ext/fts5/fts5_index.c d429598a01de4d7c64c681f395abd47189600507c5e3616b2e3576ff2011f4f3
 F ext/fts5/fts5_main.c b0fed47b3b4420ba6810373480a75bc28a9c0b7d16478d19a396436fb3ff17d7
 F ext/fts5/fts5_storage.c 46b0024fdd8002fbfba162230e5cc212c8f019ba4075396860354bfaf549a546
 F ext/fts5/fts5_tcl.c 2be6cc14f9448f720fd4418339cd202961a0801ea9424cb3d9de946f8f5a051c
@@ -170,6 +170,7 @@ F ext/fts5/test/fts5corrupt7.test 9664c15360e8b649ad76f457a0bbf5a7271b8eff1a8ee1
 F ext/fts5/test/fts5corrupt8.test 0b10750caf8aa23fa1c379ca4caf6130d41454505e4d5315590f4061eedcbe44
 F ext/fts5/test/fts5corrupt9.test 4253b9b59f33effac8b67da72ec34309c738aca2d5e8e2656bfbbd6a489a1dfe
 F ext/fts5/test/fts5corruptA.test 50b48f15548a3466dbd17000956ee86c2eb7d18d5a649bc11126ec917113b807
+F ext/fts5/test/fts5corruptB.test 0de3cb089427f152edec0046353c8468a87a98fb40afe459654fd5551cb2a605
 F ext/fts5/test/fts5corruptbig.test 9f95b40fa36e292feceab02b2ef06e21878bfa1ac7afefa138aae05518b51774
 F ext/fts5/test/fts5delete.test 2a5008f8b1174ef41d1974e606928c20e4f9da77d9f8347aed818994d89cced4
 F ext/fts5/test/fts5detail.test 54015e9c43ec4ba542cfb93268abdf280e0300f350efd08ee411284b03595cc4
@@ -2201,9 +2202,9 @@ F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee
 F tool/warnings.sh a554d13f6e5cf3760f041b87939e3d616ec6961859c3245e8ef701d1eafc2ca2
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
 F tool/winmain.c 00c8fb88e365c9017db14c73d3c78af62194d9644feaf60e220ab0f411f3604c
-P 3c8ba6dca0dcb64c21212685ca4234090e0c73fac3bdebc3f159ff03d0d93f3c
-Q +d8c59f264bdb4ad927fffd9ce78a36a6754487071ff7ce3316edbd63789d7af2
-R bc370b22524d3ab5363aaec625c4c00a
+P 713f3cf69a5e49e17785a020af7448f2882059ad41468fd45d981c90e0be1db2
+Q +74ba971bfafae1eba5e4f4a36e3b31f603f37cdc2010ee09ac251d6e863ac8b0
+R 8dbb37ec0d796b882d67454e8ca3b022
 U drh
-Z d954b5c96b46a5be95e4511982f09acb
+Z 1466ced826d18ee74ca4a9f0622b4be4
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-713f3cf69a5e49e17785a020af7448f2882059ad41468fd45d981c90e0be1db2
+f45d03b1c52ae102eb92b4de21d6a5265831cfd47e51e3193b38d60744c2e0cf