Merge checkpoint-on-close fix from wal2 branch.

FossilOrigin-Name: a92eca6c9ca45208df5764e50dec2b257244176f5893b4bee7f9475c4e8d8c8b

diff --cc manifest
index a0a0be177850f0477a7fd8533223e2f4e1571a8c,3a8447f4d323b134ed7f7ab29ff89708721090b1..8db75f34fab29ed907b4ac3b6d4403cb296b8f9c
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Merge\sversion\s3.37.0\sinto\sthe\sbegin-concurrent-pnu-wal2\sbranch.
- D 2021-11-27T15:11:55.095
 -C Fix\sa\sproblem\scausing\sone\swal\sfile\sto\sbe\sdeleted\swithout\sbeing\scheckpointed\son\sclose\sin\scases\swhere\sthe\slast\sconnection\sto\sclose\sthe\sdb\sdoes\sso\swith\san\sout\sof\sdate\swal-index\sheader\sin\smemory.
 -D 2021-12-15T12:51:02.972
++C Merge\scheckpoint-on-close\sfix\sfrom\swal2\sbranch.
++D 2021-12-15T13:42:40.710
  F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
  F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
  F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@@ -641,8 -636,8 +641,8 @@@ F src/vdbetrace.c fe0bc29ebd4e02c8bc5c1
  F src/vdbevtab.c f99b275366c5fc5e2d99f734729880994ab9500bdafde7fae3b02d562b9d323c
  F src/vtab.c 9d5c3f49d3a6959b6eef287bb8fa773563102a80a835c3314c57144412709e78
  F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
- F src/wal.c 8a81802f21762b63d0100ff240f983adcd1cb3807fc8cf73deafcd8268483e6b
 -F src/wal.c c373a0c800337f512672bc0365bc95a915df43d2e45f1427f1a02bf5e98edcee
 -F src/wal.h d01234e828943e002040c22a7e017642962f9fd9b2dc142fa599769ae4e459e9
++F src/wal.c 5b92441319c3c7cf2833e64d7d1f38efa59a9458240c991b67a105541432c3d1
 +F src/wal.h 7a733af13b966ecb81872ce397e862116b3575ea53245b90b139a2873ee87825
  F src/walker.c f890a3298418d7cba3b69b8803594fdc484ea241206a8dfa99db6dd36f8cbb3b
  F src/where.c de0d4ff409c7b62a8803f9f267cc2c7fedddbc00de9ab7b5382c507383c18665
  F src/whereInt.h 83877a75a1bce056ea44aff02f1dfa958ad1d6038c213ddadb8652003b45151d
@@@ -1738,18 -1722,18 +1738,19 @@@ F test/vtab_err.test dcc8b7b9cb67522b3f
  F test/vtab_shared.test 5253bff2355a9a3f014c15337da7e177ab0ef8ad
  F test/vtabdrop.test 65d4cf6722972e5499bdaf0c0d70ee3b8133944a4e4bc31862563f32a7edca12
  F test/wal.test 07d61ee522bc203235a7979645d6c5d84f86882afad5b678532ee37b5b85b133
 -F test/wal2.test 31f6e2c404b9f2cdf9ca19b105a1742fdc19653c2c936da39e3658c617524046
 +F test/wal2.test 88d34cc62bf5460ad6b1f837cd56ab55731bb0637ff99e113b790873d9b60b14
  F test/wal2big.test 0b4ec526f9ca4bbabc355042c38045ae2e253fb46eb327bb7693d0122bc6968b
 +F test/wal2concurrent.test 7fc3e570073683a2a28f42bda46ecf516f5bc82afd703c1fbf4aa38e18fb3361
  F test/wal2fault.test 2e8e60cacd5bcd451618aeffd05f676894d17202d3e2986e288d36e2c5993249
  F test/wal2lock.test 0ef98d72dc6bcf7711dedd684760488400d9a9a6eec0dc5d3822060437793552
+ F test/wal2openclose.test 2b26be723ea7f4263c8d5d70b37efd1c359561a0526e39466c45fe8e6478daee
  F test/wal2recover.test ba8f4bc9397c838734619f9e759bd98b00e355347b3cf80a2e677610d231d5d8
 -F test/wal2recover2.test 0c46afc759e4392a3c12fba17432b880c93a13bf4246d1be5101b00bae4c5f01
 +F test/wal2recover2.test 698bd0da28b84f470dc5dd50340401fdb50cf8d7894de27d55b61d22130bb1e1
  F test/wal2rewrite.test 6ca6f631ffcf871240beab5f02608913fd075c6d0d31310b026c8383c65c9f9c
  F test/wal2rollback.test 23adc4a099b23f6aaea8b04fdca1c35861d887dd80f8be7da2d5273eb777e428
 -F test/wal2savepoint.test 2c82bd6a6ee5066c156040d2e9c2415646fcf96116ae7ad127eaf0c0b4a85f22
 +F test/wal2savepoint.test 3793a0ae97011fca358f79775f5d7d9f85da75c8e67686e2e19713da0cb0d99c
- F test/wal2simple.test 4a9bfc34dc888e75acb4e7bdce0bf15e960cbee02f185c07a396b35c49d4431d
+ F test/wal2simple.test 320a08927f307d0ead26fa3fcef4e3f64279f49be9504f918cb33294f75aeec8
 -F test/wal2snapshot.test 7a5f4629a3c43a43c3440b8b2ea9f07de91a46b0b9eea5f08f62b5bf5b6468df
 +F test/wal2snapshot.test f6c3945bea572fd8745774e95b8dca1e5832c696e2251bb0db33391ee567fe60
  F test/wal3.test 2a93004bc0fb2b5c29888964024695bade278ab2
  F test/wal4.test 4744e155cd6299c6bd99d3eab1c82f77db9cdb3c
  F test/wal5.test 9c11da7aeccd83a46d79a556ad11a18d3cb15aa9
@@@ -1964,7 -1946,7 +1965,7 @@@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a9
  F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
  F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
  F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
- P 8a9fad0f71135b0218ccddeabb7db0c41cfac08ec772f8b3b1df7751485bc30a 3425af625bac6c89950a50c2a22c4b7f66b0080811fe16ec8879158420641d5c
- R 0a90a070d8addea4d9c4ecfd9760de90
- U drh
- Z 64736bb5cbda5070d127800560ceb017
 -P 3425af625bac6c89950a50c2a22c4b7f66b0080811fe16ec8879158420641d5c
 -R 3f40ea32fb804a93691154c1384222dd
++P 2171996a02ad2ec571570749ccee421bc0859a690c8393c5edda6cf164d2c8db b0a70a2356c44d65c54c6d9bdf05972071462e72c28d6c6e593147ffa3d27ef2
++R a8bdc946bdcbc515532b753a755a4462
+ U dan
 -Z 459a6eb607efc418f73088930cf8495d
++Z 007a67a7baf46f1b69e8ed1cd0cfdb34

diff --cc manifest.uuid
index 61faa6e268bfd41d01244ec8c4e36f7c3e2fc975,038301ccda16df157e9cf7613413eb9d6dec7f11..f5b5a8fdd1a9c516ca0a7e0b183b837aa617291e
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 2171996a02ad2ec571570749ccee421bc0859a690c8393c5edda6cf164d2c8db
 -b0a70a2356c44d65c54c6d9bdf05972071462e72c28d6c6e593147ffa3d27ef2
++a92eca6c9ca45208df5764e50dec2b257244176f5893b4bee7f9475c4e8d8c8b

diff --cc src/wal.c
Simple merge