Merge enhancements from trunk, and especially the cell-overwrite

optimization.

FossilOrigin-Name: cb3aa77802d45e9515e9c631af86f492fcd962c3302c79ba6f69213745fb0bb5

diff --cc manifest
index 339837635ed6979c1d99218d1c919309ef53426f,6862957f3f78cefb04fb02f34873e852511c2dc4..6e6145942a0dc20f866cc0e5997c0a7884779303
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,10 -1,10 +1,10 @@@
- C Bring\sthe\scode\sthat\schanges\sthe\sowner\sof\sWAL\sand\srollback\sfiles\swhen\srunning\nas\sroot\sinto\salignment\swith\strunk.
- D 2018-05-04T20:00:13.195
 -C On\san\sUPDATE,\stry\sto\soverwrite\san\sexisting\sbtree\scell\swith\sthe\smodified\ncontent,\sif\sthe\sold\sand\snew\scell\sare\sthe\ssame\ssize.\s\sUse\smemcmp()\sfirst\nto\savoid\sdirtying\spages\sthat\sare\sunchanged.
 -D 2018-05-07T11:48:22.641
++C Merge\senhancements\sfrom\strunk,\sand\sespecially\sthe\scell-overwrite\noptimization.
++D 2018-05-07T13:01:46.176
  F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
  F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 -F Makefile.in 5ce9343cba9c189046f1afe6d2bcc1f68079439febc05267b98aec6ecc752439
 +F Makefile.in 96f7c276cecf864a8abcd1b8f2b0064e28284715fe06d3def14812c81668d847
  F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 -F Makefile.msc 59179295f6a9b433e3f59a6dc2fcf6db6fcac35d92015294beb5d27f2924ebb9
 +F Makefile.msc 9e0a87c2a53a7353bf1ed03bf1f37cd8de70958811cf2138530e81a283d6f7e6
  F README.md 7764d56778d567913ef11c82da9ab94aefa0826f7c243351e4e2d7adaef6f373
  F VERSION b7c9d1d11cb70ef8e90cfcf3c944aa58a9f801cc2ad487eebb0a110c16dfc2df
  F aclocal.m4 a5c22d164aff7ed549d53a90fa56d56955281f50
@@@ -437,7 -434,7 +437,7 @@@ F src/auth.c 6277d63837357549fe14e72349
  F src/backup.c faf17e60b43233c214aae6a8179d24503a61e83b
  F src/bitvec.c 17ea48eff8ba979f1f5b04cc484c7bb2be632f33
  F src/btmutex.c 8acc2f464ee76324bf13310df5692a262b801808984c1b79defb2503bbafadb6
- F src/btree.c 76a514d839f190ac9fc2fcdfcf4e702e656368bf4936f81992edbf1ee83b2fc5
 -F src/btree.c 6be0267a7da8ca04c466094ca9d9a8a26333e175cff794afe5138aeec0cdb7c2
++F src/btree.c 10ac889edd61dea38b7563dc61722ea09bbdf5b9dd80b22d5f437d73bc717049
  F src/btree.h 0866c0a08255142ea0e754aabd211c843cab32045c978a592a43152405ed0c84
  F src/btreeInt.h 620ab4c7235f43572cf3ac2ac8723cbdf68073be4d29da24897c7b77dda5fd96
  F src/build.c 0c2be5839f22aa2938f217c6c6c2120d9fc96872a546a37541a8271541cb355e
@@@ -458,9 -455,9 +458,9 @@@ F src/hash.h ab34c5c54a9e9de2e790b24349
  F src/hwtime.h 747c1bbe9df21a92e9c50f3bbec1de841dc5e5da
  F src/in-operator.md 10cd8f4bcd225a32518407c2fb2484089112fd71
  F src/insert.c 33a2c72b6182e8ddf697d604cc087c77ff5fc512a32b8b624641d41b390e249e
 -F src/legacy.c 134ab3e3fae00a0f67a5187981d6935b24b337bcf0f4b3e5c9fa5763da95bf4e
 +F src/legacy.c 83f4499122392b1f1527a5180b1e89951bf640611ce98768bde1a9f28f0f7dde
- F src/loadext.c f6e4e416a736369f9e80eba609f0acda97148a8b0453784d670c78d3eed2f302
+ F src/loadext.c 5b89b8ca83a2f8d1f0f8c577ca45beff2e6f9124a3204600da8e22ce8b499649
 -F src/main.c b56b2d62d5d11e3f5100b25fca34c13c62a0fe73941f6873454a7fa8a454170d
 +F src/main.c 7aafeabe5655e50cfdb498a631744171b3063c8435f5334f2ec7a5f32f602ecf
  F src/malloc.c 07295435093ce354c6d9063ac05a2eeae28bd251d2e63c48b3d67c12c76f7e18
  F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
  F src/mem1.c c12a42539b1ba105e3707d0e628ad70e611040d8f5e38cf942cee30c867083de
@@@ -496,13 -493,12 +496,13 @@@ F src/printf.c d3b7844ddeb11fbbdd38dd84
  F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
  F src/resolve.c 6415381a0e9d22c0e7cba33ca4a53f81474190862f5d4838190f5eb5b0b47bc9
  F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
- F src/select.c bf9185f40cbb98a1342c0149f66dff3fbadf262081305519927523b4ec7b876e
- F src/shell.c.in 29309f2ab656c8817fbc3b7910b9af8464557b91cba75277a03669399c8e2730
+ F src/select.c a35d462ee7a3c0856ad7a9d9c8921fbf3d91d911a8f39ad9d61302eb43b24a71
+ F src/shell.c.in e41979d8bf60d3e27220bf4b4adc819254e1d24ce176089a8d14c96228efd961
 -F src/sqlite.h.in 469aed42e75193b7f5d88d812befa961c04746869475f96fcf434c9f67079f66
 +F src/sqlite.h.in 7fd42ad3247efa14010aae1fb118face5b3a7945b4954c3d6e9b142d15a8a779
  F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 +F src/sqlite3_private.h aee73ebaea1963e528b61408c01ba82f49fdf3dca9cbe940f3b0f3d9cec25942
  F src/sqlite3ext.h 83a3c4ce93d650bedfd1aa558cb85a516bd6d094445ee989740827d0d944368d
 -F src/sqliteInt.h 4b98a37f27033ca887f2027f9a60636625fb2a4a9ef1b96c17f0db8fd951891f
 +F src/sqliteInt.h e8308e4ca96cf77f495537c45239d101c221cc262dbbf187cd083646870aa7c5
  F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
  F src/status.c 46e7aec11f79dad50965a5ca5fa9de009f7d6bde08be2156f1538a0a296d4d0e
  F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
@@@ -578,14 -574,14 +578,14 @@@ F src/vdbesort.c 731a09e5cb9e96b70c394c
  F src/vdbetrace.c 48e11ebe040c6b41d146abed2602e3d00d621d7ebe4eb29b0a0f1617fd3c2f6c
  F src/vtab.c 0e4885495172e1bdf54b12cce23b395ac74ef5729031f15e1bc1e3e6b360ed1a
  F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 -F src/wal.c aa9cffc7a2bad6b826a86c8562dd4978398720ed41cb8ee7aa9d054eb8b456a0
 -F src/wal.h 8de5d2d3de0956d6f6cb48c83a4012d5f227b8fe940f3a349a4b7e85ebcb492a
 +F src/wal.c fe0187275982737e0576ba2572f75d48a4ac70f37911cb68905644e690d884da
 +F src/wal.h bada9007800e82f2765ad9ecd9f96176b45c71db769502e24de49d68c0acef65
  F src/walker.c da987a20d40145c0a03c07d8fefcb2ed363becc7680d0500d9c79915591f5b1f
- F src/where.c aa94ef44ef36763817ca952e68c03db7eee5e2d4f1f0c3a98823a58c074157bd
- F src/whereInt.h 2610cb87dd95509995b63decc674c60f2757697a206cfe0c085ee53d9c43cfff
- F src/wherecode.c 300f945eb4552fb82ccf237b34dccb22f47522882faa9adcc04388e6e3f1d4b0
+ F src/where.c d89b1aa56a75a572cd60ad27ec0fe5958d5f98b0f4391a89c72811287be7c439
+ F src/whereInt.h cbae2bcd37cfebdb7812a8b188cdb19634ced2b9346470d1c270556b0c33ea53
+ F src/wherecode.c 414ec42097b295febcae9c8803cf627580ad9005de1d8bc3afad3d3127f0eb86
  F src/whereexpr.c e90b2e76dcabc81edff56633bf281bc01d93b71e0c81482dc06925ce39f5844a
 -F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 +F test/8_3_names.test 05034aadccd2253ffe6cbefb06662b8aa4600f77
  F test/affinity2.test a6d901b436328bd67a79b41bb0ac2663918fe3bd
  F test/affinity3.test 6a101af2fc945ce2912f6fe54dd646018551710d
  F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
@@@ -1136,7 -1131,7 +1136,7 @@@ F test/oserror.test b32dc34f2363ef18532
  F test/ossfuzz.c c4c4547e2c92ac52f10038b073a03248251a23c1c559728f63a18aeca0e79f03
  F test/ossshell.c f125c5bd16e537a2549aa579b328dd1c59905e7ab1338dfc210e755bb7b69f17
  F test/ovfl.test 199c482696defceacee8c8e0e0ef36da62726b2f
- F test/pager1.test 9fe51801e819f06406f115c1a33778dfc1ae1a7804c62bd2b34c9a8f37a70178
 -F test/pager1.test a32ce299ed01ffb06e84a3af467ae1f3389786b316f40c4359f442c79144736b
++F test/pager1.test cfd1c1dd00c5d5dece44476e817cfb57b578a4c1ef1425307001da6bdfa6a24f
  F test/pager2.test 67b8f40ae98112bcdba1f2b2d03ea83266418c71
  F test/pager3.test 4e9a83d6ca0838d7c602c9eb93d1357562d9059c1e02ffb138a8271020838370
  F test/pager4.test a122e9e6925d5b23b31e3dfef8c6a44bbf19590e
@@@ -1732,7 -1727,8 +1732,7 @@@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a9
  F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
  F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
  F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
- P e17bca2cdb5f31a802e1a1870deb6bf17e332117ab272537f26351f1145de690
- R 44a53bf6621d31dd928bb370b084a0be
 -P 374d8e264487b0437a8d995ced1bc026a92d495a2d0568f65f033e9ebe11d0e2 3e11dc3183bc3e8ec49af244a8e8b3e07d12f7a2e59028b2bf64ce0ab589a91f
 -R 891ce8c2c78f1f487f80460b8c248fd0
 -T +closed 3e11dc3183bc3e8ec49af244a8e8b3e07d12f7a2e59028b2bf64ce0ab589a91f
++P 180516bf7bd5a61c11b1eef2c8c13ac63c7b00f821bb89393fc68d39852202de 5887d8beb502ad62689d31b850f46ab50831a1e9db36adf20d55ad45619d207e
++R 91c020c4417601e046dd03f4cd507fbf
  U drh
- Z fd63f96833cdf5b1062ab51228464a2a
 -Z 7955ef5d032aea210d99e8bc24e906bc
++Z 67ccb61d54ee276a2e32b9a538cbd9c8

diff --cc manifest.uuid
index 6b8be5190ab19940aef9b15af1343350c0207082,3fa7a09c8ab979bff8e5176bed5b7c96681c2ca9..0f640514e87b2d13641ac999c03f05893493e734
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 180516bf7bd5a61c11b1eef2c8c13ac63c7b00f821bb89393fc68d39852202de
 -5887d8beb502ad62689d31b850f46ab50831a1e9db36adf20d55ad45619d207e
++cb3aa77802d45e9515e9c631af86f492fcd962c3302c79ba6f69213745fb0bb5

diff --cc src/btree.c
Simple merge

diff --cc test/pager1.test
Simple merge