diff --git a/manifest b/manifest
index b5661ba17e..3c7a4ef6e2 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Merge\sall\srecent\strunk\senhancements\sinto\sthe\swal-shm-exceptions\sbranch.
-D 2023-07-06T17:55:33.956
+C Merge\sthe\slatest\strunk\senhancements\sinto\sthe\swal-shm-exceptions\sbranch.
+D 2023-07-10T18:05:23.333
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -377,7 +377,7 @@ F ext/rbu/rbuvacuum4.test ffccd22f67e2d0b380d2889685742159dfe0d19a3880ca3d2d1d69
 F ext/rbu/sqlite3rbu.c d4ddf8f0e93772556e452a6c2814063cf47efb760a0834391a9d0cd9859fa4b9
 F ext/rbu/sqlite3rbu.h 9d923eb135c5d04aa6afd7c39ca47b0d1d0707c100e02f19fdde6a494e414304
 F ext/rbu/test_rbu.c ee6ede75147bc081fe9bc3931e6b206277418d14d3fbceea6fdc6216d9b47055
-F ext/recover/dbdata.c 81661e3a98cabb70be8f2760a67a8d6d5bf7aaa7a4055a53ff915ac884221a64 w ext/misc/dbdata.c
+F ext/recover/dbdata.c 81661e3a98cabb70be8f2760a67a8d6d5bf7aaa7a4055a53ff915ac884221a64
 F ext/recover/recover1.test c484d01502239f11b61f23c1cee9f5dd19fa17617f8974e42e74d64639c524cf
 F ext/recover/recover_common.tcl a61306c1eb45c0c3fc45652c35b2d4ec19729e340bdf65a272ce4c229cefd85a
 F ext/recover/recoverbuild.test c74170e0f7b02456af41838afeb5353fdb985a48cc2331d661bbabbca7c6b8e3
@@ -568,7 +568,7 @@ F spec.template 86a4a43b99ebb3e75e6b9a735d5fd293a24e90ca
 F sqlite.pc.in 42b7bf0d02e08b9e77734a47798d1a55a9e0716b
 F sqlite3.1 fc7ad8990fc8409983309bb80de8c811a7506786
 F sqlite3.pc.in 48fed132e7cb71ab676105d2a4dc77127d8c1f3a
-F sqlite_cfg.h.in baf2e409c63d4e7a765e17769b6ff17c5a82bbd9cbf1e284fd2e4cefaff3fcf2 w config.h.in
+F sqlite_cfg.h.in baf2e409c63d4e7a765e17769b6ff17c5a82bbd9cbf1e284fd2e4cefaff3fcf2
 F src/alter.c 3ff8c2fca0c0636d43459154bb40d79c882df1b34df77f89c4ec47ab2e2389f5
 F src/analyze.c d4cc28738c29e009640ec20ebb6936ba6fcefff0d11aa93398d9bb9a5ead6c1f
 F src/attach.c cc9d00d30da916ff656038211410ccf04ed784b7564639b9b61d1839ed69fd39
@@ -576,7 +576,7 @@ F src/auth.c 19b7ccacae3dfba23fc6f1d0af68134fa216e9040e53b0681b4715445ea030b4
 F src/backup.c 5c97e8023aab1ce14a42387eb3ae00ba5a0644569e3476f38661fa6f824c3523
 F src/bitvec.c 9eac5f42c11914d5ef00a75605bb205e934f435c579687f985f1f8b0995c8645
 F src/btmutex.c 79a43670447eacc651519a429f6ece9fd638563cf95b469d6891185ddae2b522
-F src/btree.c c0c93b6cb4dc133b528c1290bb4ad0f2414452f9a5758ff2b106af718874f39e
+F src/btree.c c9400cc1509116a29120dc06feb00ca7e26b5a4a6dba80758b1ba109d8fce5a4
 F src/btree.h aa354b9bad4120af71e214666b35132712b8f2ec11869cb2315c52c81fad45cc
 F src/btreeInt.h 3b4eff7155c0cea6971dc51f62e3529934a15a6640ec607dd42a767e379cb3a9
 F src/build.c a8ae3b32d9aa9bbd2c0e97d7c0dd80def9fbca408425de1608f57ee6f47f45f4
@@ -590,17 +590,17 @@ F src/delete.c cd5f5cd06ed0b6a882ec1a8c2a0d73b3cecb28479ad19e9931c4706c5e2182be
 F src/expr.c 8d1656b65e26af3e34f78e947ac423f0d20c214ed25a67486e433bf16ca6b543
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c a7fcbf7e66d14dbb73cf49f31489ebf66d0e6006c62b95246924a3bae9f37b36
-F src/func.c 994a3a30d36c079c6e26d6653d770153675590daa549d3692eb38c5ac05dc663
-F src/global.c a16553245e315ee0cda8f9b0bf744efef9dc99f86e9d77f58975ea58824ded92
+F src/func.c cffa6edb4aa4865d8e237022399ba9c2b22fd11e5581efba7c5b524b525952ca
+F src/global.c 29f56a330ed9d1b5cd9b79ac0ca36f97ac3afc730ff8bfa987b0db9e559d684d
 F src/hash.c 9ee4269fb1d6632a6fecfb9479c93a1f29271bddbbaf215dd60420bcb80c7220
 F src/hash.h 3340ab6e1d13e725571d7cee6d3e3135f0779a7d8e76a9ce0a85971fa3953c51
 F src/hwtime.h f9c2dfb84dce7acf95ce6d289e46f5f9d3d1afd328e53da8f8e9008e3b3caae6
 F src/in-operator.md 10cd8f4bcd225a32518407c2fb2484089112fd71
 F src/insert.c 3f0a94082d978bbdd33c38fefea15346c6c6bffb70bc645a71dc0f1f87dd3276
-F src/json.c 14c474fb1249a46eb44e878e2361f36abfe686b134039b0d1883d93d61505b4a w ext/misc/json1.c
+F src/json.c 14c474fb1249a46eb44e878e2361f36abfe686b134039b0d1883d93d61505b4a
 F src/legacy.c d7874bc885906868cd51e6c2156698f2754f02d9eee1bae2d687323c3ca8e5aa
 F src/loadext.c 176d6b2cb18a6ad73b133db17f6fc351c4d9a2d510deebdb76c22bde9cfd1465
-F src/main.c 7bc04e53851c813454b73083e21f84fd8a6d3d32eaa242bb4974eda870e28fef
+F src/main.c 512b1d45bc556edf4471a845afb7ba79e64bd5b832ab222dc195c469534cd002
 F src/malloc.c 47b82c5daad557d9b963e3873e99c22570fb470719082c6658bf64e3012f7d23
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c 3bb59158c38e05f6270e761a9f435bf19827a264c13d1631c58b84bdc96d73b2
@@ -638,16 +638,16 @@ F src/random.c 606b00941a1d7dd09c381d3279a058d771f406c5213c9932bbd93d5587be4b9c
 F src/resolve.c 37953a5f36c60bea413c3c04efcd433b6177009f508ef2ace0494728912fe2e9
 F src/rowset.c 8432130e6c344b3401a8874c3cb49fefe6873fec593294de077afea2dce5ec97
 F src/select.c 3ab1186290a311a8ceed1286c0e286209f7fe97b2d02c7593258004ce295dd88
-F src/shell.c.in e01d7e1d8a6b158320c97c955e1b14763289b82a73e3a155fa8efe0d546f0567
+F src/shell.c.in d320d8a13636de06d777cc1eab981caca304e175464e98183cf4ea68d93db818
 F src/sqlite.h.in 6a0ffe5886af2528baff6087efb34a4915d2ff394d15df32e6e2de8524b756d2
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h da473ce2b3d0ae407a6300c4a164589b9a6bfdbec9462688a8593ff16f3bb6e4
-F src/sqliteInt.h f6c5470b7db42318a3de1115757e94b76570ad7697ac547823e01f1166756f1d
+F src/sqliteInt.h 002a6c3e24752d123468c5d948a80e2cd4acf01badce268f9dd98b581cd7bb96
 F src/sqliteLimit.h 33b1c9baba578d34efe7dfdb43193b366111cdf41476b1e82699e14c11ee1fb6
 F src/status.c 160c445d7d28c984a0eae38c144f6419311ed3eace59b44ac6dafc20db4af749
 F src/table.c 0f141b58a16de7e2fbe81c308379e7279f4c6b50eb08efeec5892794a0ba30d1
 F src/tclsqlite.c ecbc3c99c0d0c3ed122a913f143026c26d38d57f33e06bb71185dd5c1efe37cd
-F src/test1.c 86099cc02f22069d75b04ae9c105acde0edbce9033d5ac37262bad2e461e6000
+F src/test1.c 9111b12427b3b94429aff68bbcf5b125ae70438f6ce2f3f033e2a69626ec26c9
 F src/test2.c 827446e259a3b7ab949da1542953edda7b5117982576d3e6f1c24a0dd20a5cef
 F src/test3.c e5178558c41ff53236ae0271e9acb3d6885a94981d2eb939536ee6474598840e
 F src/test4.c 4533b76419e7feb41b40582554663ed3cd77aaa54e135cf76b3205098cd6e664
@@ -705,7 +705,7 @@ F src/trigger.c ad6ab9452715fa9a8075442e15196022275b414b9141b566af8cdb7a1605f2b0
 F src/update.c 0aa36561167a7c40d01163238c297297962f31a15a8d742216b3c37cdf25f731
 F src/upsert.c 5303dc6c518fa7d4b280ec65170f465c7a70b7ac2b22491598f6d0b4875b3145
 F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0
-F src/util.c 5b7b61614e33f6bbbe251af90a2097082cc16870949a8cdef834ed9919e65425
+F src/util.c 161e49e88b080c2370a4990aa55f51f9edcaf8c41c3cb06cd4c37ffde1c85e6d
 F src/vacuum.c 604fcdaebe76f3497c855afcbf91b8fa5046b32de3045bab89cc008d68e40104
 F src/vdbe.c 74282a947234513872a83b0bab1b8c644ece64b3e27b053ef17677c8ff9c81e0
 F src/vdbe.h 41485521f68e9437fdb7ec4a90f9d86ab294e9bb8281e33b235915e29122cfc0
@@ -713,13 +713,13 @@ F src/vdbeInt.h 7bd49eef8f89c1a271fbf12d80a206bf56c876814c5fc6bee340f4e1907095ae
 F src/vdbeapi.c de9703f8705afc393cc2864669ce28cf9516983c8331d59aa2b978de01634365
 F src/vdbeaux.c d56f179577cee110d1d60129a07d37035e85b0d39a272d7587f3dbb99b40b94a
 F src/vdbeblob.c 2516697b3ee8154eb8915f29466fb5d4f1ae39ee8b755ea909cefaf57ec5e2ce
-F src/vdbemem.c aed58a560caab12540f7c14c43ee188636017814e21247a97902f78de2d43117
+F src/vdbemem.c cf4a1556dd5b18c071cf7c243373c29ce752eb516022e3ad49ba72f08b785033
 F src/vdbesort.c 0d40dca073c94e158ead752ef4225f4fee22dee84145e8c00ca2309afb489015
 F src/vdbetrace.c fe0bc29ebd4e02c8bc5c1945f1d2e6be5927ec12c06d89b03ef2a4def34bf823
 F src/vdbevtab.c aae4bd769410eb7e1d02c42613eec961d514459b1c3c1c63cfc84e92a137daac
 F src/vtab.c 1ecf8c3745d29275688d583e12822fa984d421e0286b5ef50c137bc3bf6d7a64
 F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
-F src/wal.c 7f6fba5d543b0a6bc434bc7b61a7706355449404289087042485a97c4edd469d
+F src/wal.c df70125aa233626b8aa56dd6be7cbbe7234e10e01a0610152e583b65eeebc474
 F src/wal.h 04a9e53121d5076f2a173b0f2facb39d33047093fee71bd3bbe6b1f6f1f5fd4b
 F src/walker.c 7c7ea0115345851c3da4e04e2e239a29983b61fb5b038b94eede6aba462640e2
 F src/where.c 2dc708cf8b6a691fb79f16bbc46567497ee6f991043318d421e294b2da114d93
@@ -1393,7 +1393,7 @@ F test/recover.test fd5199f928757cb308661b5fdca1abc19398a798ff7f24b57c3071e9f8e0
 F test/regexp1.test 8f2a8bc1569666e29a4cee6c1a666cd224eb6d50e2470d1dc1df995170f3e0f1
 F test/regexp2.test 55ed41da802b0e284ac7e2fe944be3948f93ff25abbca0361a609acfed1368b5
 F test/reindex.test cd9d6021729910ece82267b4f5e1b5ac2911a7566c43b43c176a6a4732e2118d
-F test/releasetest_data.tcl b550dd1b122a9c969df794d05ea272df535f10ff1a245062e7ba080822378016
+F test/releasetest_data.tcl c8cf85aeb313a771e18dae01396f5ca70e85d4574df681990629b1103f185afe
 F test/resetdb.test 54c06f18bc832ac6d6319e5ab23d5c8dd49fdbeec7c696d791682a8006bd5fc3
 F test/resolver01.test f4022acafda7f4d40eca94dbf16bc5fc4ac30ceb
 F test/returning1.test db532cde29d6aebbc48c6ddc3149b30476f8e69ca7a2c4b53986c7635e6fd8ec
@@ -2044,8 +2044,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 13a524b351a0812214b223aa4e0a9d778ae7a75cf9875da1147a09c5cb76b9fe ad2e39626e6115fd322ef9495ae3bcd91343d7131a725f1bf24211a51a21dcc2
-R 3e69d81c6558ef42f8b74b7ecdd6ab2d
+P e59cea2d851be68559e7d01a01cb05684c44d151d022ea9790ce99671016ab00 07d95ed60f0a17ea13b4bc19c2ab2ec9052fedd27c9e1e57a1ec6e3a6470e5b7
+R ccbc614d43527056706e7e54f93af172
 U drh
-Z 91a5c6cfeac66999b4150b279524c11c
+Z da656ee3765bdd3f9ae04fb3fd79cf86
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 7968ae6fb4..8d0a378f48 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-e59cea2d851be68559e7d01a01cb05684c44d151d022ea9790ce99671016ab00
\ No newline at end of file
+f655d08d019bab0c578886e91ca24fd956d1b3dea9b9c9104812b3cf62e5e556
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index aa4e286013..643d1c42de 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -5341,6 +5341,7 @@ static int moveToChild(BtCursor *pCur, u32 newPgno){
   pCur->ix = 0;
   pCur->iPage++;
   rc = getAndInitPage(pCur->pBt, newPgno, &pCur->pPage, pCur->curPagerFlags);
+  assert( pCur->pPage!=0 || rc!=SQLITE_OK );
   if( rc==SQLITE_OK
    && (pCur->pPage->nCell<1 || pCur->pPage->intKey!=pCur->curIntKey)
   ){
@@ -5569,7 +5570,7 @@ int sqlite3BtreeFirst(BtCursor *pCur, int *pRes){
     *pRes = 0;
     rc = moveToLeftmost(pCur);
   }else if( rc==SQLITE_EMPTY ){
-    assert( pCur->pgnoRoot==0 || pCur->pPage->nCell==0 );
+    assert( pCur->pgnoRoot==0 || (pCur->pPage!=0 && pCur->pPage->nCell==0) );
     *pRes = 1;
     rc = SQLITE_OK;
   }
diff --git a/src/func.c b/src/func.c
index beafb54312..542d71a23d 100644
--- a/src/func.c
+++ b/src/func.c
@@ -1704,11 +1704,14 @@ static void kahanBabuskaNeumaierStep(
 ** Add a (possibly large) integer to the running sum.
 */
 static void kahanBabuskaNeumaierStepInt64(volatile SumCtx *pSum, i64 iVal){
-  volatile double rVal = (double)iVal;
-  kahanBabuskaNeumaierStep(pSum, rVal);
-  if( iVal<=-4503599627370496 || iVal>=+4503599627370496 ){
-    double rDiff = (double)(iVal - (i64)rVal);
-    kahanBabuskaNeumaierStep(pSum, rDiff);
+  if( iVal<=-4503599627370496LL || iVal>=+4503599627370496LL ){
+    i64 iBig, iSm;
+    iSm = iVal % 16384;
+    iBig = iVal - iSm;
+    kahanBabuskaNeumaierStep(pSum, iBig);
+    kahanBabuskaNeumaierStep(pSum, iSm);
+  }else{
+    kahanBabuskaNeumaierStep(pSum, (double)iVal);
   }
 }
 
@@ -1716,11 +1719,17 @@ static void kahanBabuskaNeumaierStepInt64(volatile SumCtx *pSum, i64 iVal){
 ** Initialize the Kahan-Babaska-Neumaier sum from a 64-bit integer
 */
 static void kahanBabuskaNeumaierInit(
-  volatile SumCtx *pSum,
+  volatile SumCtx *p,
   i64 iVal
 ){
-  pSum->rSum = (double)iVal;
-  pSum->rErr = (double)(iVal - (i64)pSum->rSum);
+  if( iVal<=-4503599627370496LL || iVal>=+4503599627370496LL ){
+    i64 iSm = iVal % 16384;
+    p->rSum = (double)(iVal - iSm);
+    p->rErr = (double)iSm;
+  }else{
+    p->rSum = (double)iVal;
+    p->rErr = 0.0;
+  }
 }
 
 /*
diff --git a/src/global.c b/src/global.c
index dc765522ec..60cd13e2ab 100644
--- a/src/global.c
+++ b/src/global.c
@@ -243,7 +243,7 @@ SQLITE_WSD struct Sqlite3Config sqlite3Config = {
    SQLITE_ALLOW_COVERING_INDEX_SCAN,   /* bUseCis */
    0,                         /* bSmallMalloc */
    1,                         /* bExtraSchemaChecks */
-   sizeof(long double)>8,     /* bUseLongDouble */
+   sizeof(LONGDOUBLE_TYPE)>8, /* bUseLongDouble */
    0x7ffffffe,                /* mxStrlen */
    0,                         /* neverCorrupt */
    SQLITE_DEFAULT_LOOKASIDE,  /* szLookaside, nLookaside */
diff --git a/src/main.c b/src/main.c
index 19f65dac6f..8f21af13ee 100644
--- a/src/main.c
+++ b/src/main.c
@@ -4472,11 +4472,14 @@ int sqlite3_test_control(int op, ...){
 
     /* sqlite3_test_control(SQLITE_TESTCTRL_USELONGDOUBLE, int X);
     **
-    ** Enable long double usage if X>0.  Disable if X==0.  No-op if X<0.
-    ** Return the status of long double usage afterwards.
+    **   X<0     Make no changes to the bUseLongDouble.  Just report value.
+    **   X==0    Disable bUseLongDouble
+    **   X==1    Enable bUseLongDouble
+    **   X==2    Set bUseLongDouble to its default value for this platform
     */
     case SQLITE_TESTCTRL_USELONGDOUBLE: {
       int b = va_arg(ap, int);
+      if( b==2 ) b = sizeof(LONGDOUBLE_TYPE)>8;
       if( b>=0 ) sqlite3Config.bUseLongDouble = b>0;
       rc = sqlite3Config.bUseLongDouble!=0;
       break;
diff --git a/src/shell.c.in b/src/shell.c.in
index 295d405cbd..9165f21f71 100644
--- a/src/shell.c.in
+++ b/src/shell.c.in
@@ -10876,7 +10876,7 @@ static int do_meta_command(char *zLine, ShellState *p){
     {"seek_count",         SQLITE_TESTCTRL_SEEK_COUNT,  0, ""               },
     {"sorter_mmap",        SQLITE_TESTCTRL_SORTER_MMAP, 0, "NMAX"           },
     {"tune",               SQLITE_TESTCTRL_TUNE,        1, "ID VALUE"       },
-    {"uselongdouble",      SQLITE_TESTCTRL_USELONGDOUBLE,0,"BOOLEAN"        },
+    {"uselongdouble",    SQLITE_TESTCTRL_USELONGDOUBLE,0,"?BOOLEAN|\"default\"?"},
     };
     int testctrl = -1;
     int iCtrl = -1;
@@ -11000,7 +11000,14 @@ static int do_meta_command(char *zLine, ShellState *p){
 
         /* sqlite3_test_control(int, int) */
         case SQLITE_TESTCTRL_USELONGDOUBLE: {
-          int opt = nArg==3 ? booleanValue(azArg[2]) : -1;
+          int opt = -1;
+          if( nArg==3 ){
+            if( cli_strcmp(azArg[2],"default")==0 ){
+              opt = 2;
+            }else{
+              opt = booleanValue(azArg[2]);
+            }
+          }
           rc2 = sqlite3_test_control(testctrl, opt);
           isOk = 1;
           break;
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 8eae8d166a..770aa70718 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -4608,7 +4608,8 @@ struct FpDecode {
   char isSpecial;      /* 1: Infinity  2: NaN */
   int n;               /* Significant digits in the decode */
   int iDP;             /* Location of the decimal point */
-  char z[24];          /* Significiant digits */
+  char *z;             /* Start of significant digits */
+  char zBuf[24];       /* Storage for significant digits */
 };
 
 void sqlite3FpDecode(FpDecode*,double,int,int);
diff --git a/src/test1.c b/src/test1.c
index acae44c8ac..adc862156f 100644
--- a/src/test1.c
+++ b/src/test1.c
@@ -7099,11 +7099,14 @@ static int SQLITE_TCLAPI extra_schema_checks(
 }
 
 /*
-** tclcmd:  use_long_double INT
+** tclcmd:  use_long_double BOOLEAN|"default"
 **
-** Enable or disable the use of long double.   Enable if the argument is
-** positive.  Disable if the argument is zero.  No-op if the argument is
-** negative.
+** If no argument, report the current value of the use-long-double flag.
+**
+** If argument is "default", set the use-long-double flag to the default
+** value for this build, based on the size of LONGDOUBLE_TYPE.
+**
+** If argument is a boolean, set the use-long-double flag accordingly.
 **
 ** Return the new setting.
 */
@@ -7115,7 +7118,11 @@ static int SQLITE_TCLAPI use_long_double(
 ){
   int i = -1;
   if( objc==2 ){
-    if( Tcl_GetBooleanFromObj(interp,objv[1],&i) ) return TCL_ERROR;
+    if( strcmp(Tcl_GetString(objv[1]),"default")==0 ){
+      i = 2;
+    }else{
+      if( Tcl_GetBooleanFromObj(interp,objv[1],&i) ) return TCL_ERROR;
+    }
   }
   i = sqlite3_test_control(SQLITE_TESTCTRL_USELONGDOUBLE, i);
   Tcl_SetObjResult(interp, Tcl_NewIntObj(i));
diff --git a/src/util.c b/src/util.c
index a5ed68c643..ee13a380f5 100644
--- a/src/util.c
+++ b/src/util.c
@@ -422,11 +422,11 @@ static void dekkerMul2(volatile double *x, double y, double yy){
   double hx, hy;
   u64 m;
   memcpy(&m, (void*)&x[0], 8);
-  m &= 0xfffffffffc000000L;
+  m &= 0xfffffffffc000000LL;
   memcpy(&hx, &m, 8);
   tx = x[0] - hx;
   memcpy(&m, &y, 8);
-  m &= 0xfffffffffc000000L;
+  m &= 0xfffffffffc000000LL;
   memcpy(&hy, &m, 8);
   ty = y - hy;
   p = hx*hy;
@@ -950,12 +950,18 @@ int sqlite3Atoi(const char *z){
 ** n is positive.  Or round to -n signficant digits after the
 ** decimal point if n is negative.  No rounding is performed if
 ** n is zero.
+**
+** The significant digits of the decimal representation are
+** stored in p->z[] which is a often (but not always) a pointer
+** into the middle of p->zBuf[].  There are p->n significant digits.
+** The p->z[] array is *not* zero-terminated.
 */
 void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){
   int i;
   u64 v;
   int e, exp = 0;
   p->isSpecial = 0;
+  p->z = p->zBuf;
 
   /* Convert negative numbers to positive.  Deal with Infinity, 0.0, and
   ** NaN. */
@@ -966,7 +972,7 @@ void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){
     p->sign = '+';
     p->n = 1;
     p->iDP = 1;
-    p->z[0] = '0';
+    p->z = "0";
     return;
   }else{
     p->sign = '+';
@@ -974,7 +980,7 @@ void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){
   memcpy(&v,&r,8);
   e = v>>52;
   if( (e&0x7ff)==0x7ff ){
-    p->isSpecial = 1 + (v!=0x7ff0000000000000L);
+    p->isSpecial = 1 + (v!=0x7ff0000000000000LL);
     p->n = 0;
     p->iDP = 0;
     return;
@@ -1040,21 +1046,25 @@ void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){
 
 
   /* Extract significant digits. */
-  i = sizeof(p->z)-1;
-  while( v ){  p->z[i--] = (v%10) + '0'; v /= 10; }
-  p->n = sizeof(p->z) - 1 - i;
+  i = sizeof(p->zBuf)-1;
+  assert( v>0 );
+  while( v ){  p->zBuf[i--] = (v%10) + '0'; v /= 10; }
+  assert( i>=0 && i<sizeof(p->zBuf)-1 );
+  p->n = sizeof(p->zBuf) - 1 - i;
+  assert( p->n>0 );
+  assert( p->n<sizeof(p->zBuf) );
   p->iDP = p->n + exp;
   if( iRound<0 ){
     iRound = p->iDP - iRound;
-    if( iRound==0 && p->z[i+1]>='5' ){
+    if( iRound==0 && p->zBuf[i+1]>='5' ){
       iRound = 1;
-      p->z[i--] = '0';
+      p->zBuf[i--] = '0';
       p->n++;
       p->iDP++;
     }
   }
   if( iRound>0 && (iRound<p->n || p->n>mxRound) ){
-    char *z = &p->z[i+1];
+    char *z = &p->zBuf[i+1];
     if( iRound>mxRound ) iRound = mxRound;
     p->n = iRound;
     if( z[iRound]>='5' ){
@@ -1074,7 +1084,8 @@ void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){
       }
     }
   }
-  memmove(p->z, &p->z[i+1], p->n);
+  p->z = &p->zBuf[i+1];
+  assert( i+p->n < sizeof(p->zBuf) );
   while( ALWAYS(p->n>0) && p->z[p->n-1]=='0' ){ p->n--; }
 }
 
diff --git a/src/vdbemem.c b/src/vdbemem.c
index fa29e91521..1250eea77d 100644
--- a/src/vdbemem.c
+++ b/src/vdbemem.c
@@ -731,8 +731,8 @@ int sqlite3RealSameAsInt(double r1, sqlite3_int64 i){
 ** from UBSAN.
 */
 i64 sqlite3RealToI64(double r){
-  if( r<=(double)SMALLEST_INT64 ) return SMALLEST_INT64;
-  if( r>=(double)LARGEST_INT64) return LARGEST_INT64;
+  if( r<-9223372036854774784.0 ) return SMALLEST_INT64;
+  if( r>+9223372036854774784.0 ) return LARGEST_INT64;
   return (i64)r;
 }
 
diff --git a/src/wal.c b/src/wal.c
index b9146528d7..1e1382129b 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -666,7 +666,7 @@ static void sehInjectFault(Wal *pWal){
     aArg[0] = 0;
     aArg[1] = 0;
     aArg[2] = (ULONG)res;
-    RaiseException(EXCEPTION_IN_PAGE_ERROR, 0, 3, aArg);
+    RaiseException(EXCEPTION_IN_PAGE_ERROR, 0, 3, (const ULONG*)aArg);
   }
 }
 
diff --git a/test/releasetest_data.tcl b/test/releasetest_data.tcl
index 2f4e71e8ce..0744812990 100644
--- a/test/releasetest_data.tcl
+++ b/test/releasetest_data.tcl
@@ -257,6 +257,7 @@ array set ::Configs [strip_comments {
     -DSQLITE_ENABLE_FTS4
     -DSQLITE_ENABLE_RTREE
     -DSQLITE_ENABLE_HIDDEN_COLUMNS
+    -DLONGDOUBLE_TYPE=double
     -DCONFIG_SLOWDOWN_FACTOR=8.0
   }