Add enhanced resistance to corruption after posix advisory locks on the

database file been unintentionally broken on unix by running
close(open(DBFILE)) from a separate thread.

FossilOrigin-Name: 6385a1962c69c69ca4775888f034a4eb892aa013689c000f3de6422da7c3c695

diff --cc manifest
index 7d1e1f5059fd204fb8291bc3df3ed431cdccd61e,e381e5f1cdabf770dc633f055774fe396950cf67..f1c0ea646de46f9705c618cb449bf8157f7fe9e7
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Enhance\sthe\sCLI\sso\sthat\sit\scan\shandle\sinputs\slarger\sthan\s2\sbillion\slines.
- D 2025-10-28T10:44:26.253
 -C Additional\scomments\sexplaining\swhat\sunixIsSharingShmNode()\sdoes.\s\sNo\nchanges\sto\scode.
 -D 2025-10-28T01:28:20.819
++C Add\senhanced\sresistance\sto\scorruption\safter\sposix\sadvisory\slocks\son\sthe\ndatabase\sfile\sbeen\sunintentionally\sbroken\son\sunix\sby\srunning\nclose(open(DBFILE))\sfrom\sa\sseparate\sthread.
++D 2025-10-28T10:50:55.157
  F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
  F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
  F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@@ -2171,8 -2171,8 +2171,9 @@@ F tool/version-info.c 33d0390ef484b3b1c
  F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee87c1b31a7
  F tool/warnings.sh 1ad0169b022b280bcaaf94a7fa231591be96b514230ab5c98fbf15cd7df842dd
  F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
- P 1803cb9bb6a13fb66956f729066b6eae64c3a1c0715102fb1a9994e395c12ba9
- R 50be0ae2403a4de82fb245ed40141391
 -P 2d5623bc27073c407ec63e401f095d12f0025dd276a0bdc26d8b94b1f13c9a36
 -R b4fa08ce2106f467a95e7d2084e4ddb2
++P 5daebf2d6013e73d89c9feb796e15b67c39577e5a9e9c86fa260995f4118f04b 819fc87385fd5be8a847492478f4c4f247f64edf7c7161b641bfbac6b658bec5
++R da1eafeba35515ba40fda65d5ff3ec66
++T +closed 819fc87385fd5be8a847492478f4c4f247f64edf7c7161b641bfbac6b658bec5
  U drh
- Z 3002323c72a643b625fa2973294110d0
 -Z 9fdddb7cbd1691bae27c3687057e444b
++Z 14d2e925da00cbf7f490a0a0f413fd0f
  # Remove this line to create a well-formed Fossil manifest.

diff --cc manifest.uuid
index 872987abde64887fdbf3faea3fa24b4750978b53,26869b0239f8ec9ee050c1d14dfc9597c9eb174e..2ad7641c568a21c9d9a60819ff0cc53116f2f315
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 5daebf2d6013e73d89c9feb796e15b67c39577e5a9e9c86fa260995f4118f04b
 -819fc87385fd5be8a847492478f4c4f247f64edf7c7161b641bfbac6b658bec5
++6385a1962c69c69ca4775888f034a4eb892aa013689c000f3de6422da7c3c695