In the sqlite3SelectDup() routine, do not do an incomplete duplication due

to OOM.  This in turn requires several new NEVER() and ALWAYS() macros for
unreachable branches.

FossilOrigin-Name: a61c0e6b78bd39f55464fafd257e68effded64995a66e8fa2d686e8c507ebe43

7 files changed, 24 insertions, 16 deletions

diff --git a/manifest b/manifest
index 1468ff515..04fa36690 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Improvement\sto\scheck-in\s[d564d8882ef18b55]\sto\sdetect\sthe\sOOM\sfault\seven\nif\sit\soccurs\sdeep\sdown\sinside\sthe\sduplicated\sexpression.
-D 2021-04-19T20:36:13.043
+C In\sthe\ssqlite3SelectDup()\sroutine,\sdo\snot\sdo\san\sincomplete\sduplication\sdue\nto\sOOM.\s\sThis\sin\sturn\srequires\sseveral\snew\sNEVER()\sand\sALWAYS()\smacros\sfor\nunreachable\sbranches.
+D 2021-04-20T12:14:12.835
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -476,7 +476,7 @@ F spec.template 86a4a43b99ebb3e75e6b9a735d5fd293a24e90ca
 F sqlite.pc.in 42b7bf0d02e08b9e77734a47798d1a55a9e0716b
 F sqlite3.1 fc7ad8990fc8409983309bb80de8c811a7506786
 F sqlite3.pc.in 48fed132e7cb71ab676105d2a4dc77127d8c1f3a
-F src/alter.c 9dde656dfd53325dae24973fa7d6597ef64dcfd1bc3c3baefcf7b88c5af0d0a8
+F src/alter.c e7caf3eefce268250dc1d10322eec637319de486aa1bae7f48c606259455537e
 F src/analyze.c 01c6c6765cb4d40b473b71d85535093730770bb186f2f473abac25f07fcdee5c
 F src/attach.c 8783d67d2c61371dfae46e4043158d44b73c14154d62560cd4cb1e0dfc6337a1
 F src/auth.c 08954fdc4cc2da5264ba5b75cfd90b67a6fc7d1710a02ccf917c38eadec77853
@@ -486,7 +486,7 @@ F src/btmutex.c 8acc2f464ee76324bf13310df5692a262b801808984c1b79defb2503bbafadb6
 F src/btree.c 15cfe91aa3b3b91d3dc20faaa7c64b627ca9794b22be8b184054cb6b947505fc
 F src/btree.h 096cc53baa58be22b02c896d1cf933c38cfc6d65f9253c1367ece8cc88a24de5
 F src/btreeInt.h 7bc15a24a02662409ebcd6aeaa1065522d14b7fda71573a2b0568b458f514ae0
-F src/build.c 1cf8ab071ebab0ee8e26eae02b47b4316f69d8b33cc85031fbb356e4b2dbb624
+F src/build.c 45889a1ac425eb7d60113ce65a519c55c5d5d01f2a9e978ab1467f8653bb57eb
 F src/callback.c d0b853dd413255d2e337b34545e54d888ea02f20da5ad0e63585b389624c4a6c
 F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
 F src/ctime.c 2a322b9a3d75771fb4d99e0702851f4f68dda982507a0f798eefb0712969a410
@@ -494,7 +494,7 @@ F src/date.c e0632f335952b32401482d099321bbf12716b29d6e72836b53ae49683ebae4bf
 F src/dbpage.c 8a01e865bf8bc6d7b1844b4314443a6436c07c3efe1d488ed89e81719047833a
 F src/dbstat.c 3aa79fc3aed7ce906e4ea6c10e85d657299e304f6049861fe300053ac57de36c
 F src/delete.c 73f57a9a183532c344a3135cf8f2a5589376e39183e0b5f562d6b61b2af0f4d8
-F src/expr.c f1e3474d693e7dbc75726d7c23a6bb55e7205af8059956c5b3005745eb62990a
+F src/expr.c 2b79c16f167b7ec74dfbd325b6f9cd9ff026908017f6804a5af6ba451c13b5b1
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c e9063648396c58778f77583a678342fe4a9bc82436bf23c5f9f444f2df0fdaa4
 F src/func.c 88fd711754a7241cb9f8eb1391370fd0c0cea756b3358efa274c5d1efd59af93
@@ -542,7 +542,7 @@ F src/printf.c 78fabb49b9ac9a12dd1c89d744abdc9b67fd3205e62967e158f78b965a29ec4b
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c e299d53c4077fc32bc63741b5b27fdf8a1328cb8e812b9fafb55441c4c73a80a
 F src/rowset.c ba9515a922af32abe1f7d39406b9d35730ed65efab9443dc5702693b60854c92
-F src/select.c 2c4f89257327581f918863d49aded6087552926de799c0d0ebea70200c478cb2
+F src/select.c bc08a79364ad2056b1b3b83142b1cc4eacabf850603166f3a72581d56c320d9c
 F src/shell.c.in 9320b476fde0f7c46700e5695b69b435f1e46843a1513cdd187ac426cdbee016
 F src/sqlite.h.in 18ec33e32001721fd4e9c4705a24a85dff04956ac2c0a21775058884ba845b09
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
@@ -628,7 +628,7 @@ F src/vtab.c 032a0165c147fda16927e6a3230e90c068d4af93f887ce94e26f678fe48e5e4c
 F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 69e770e96fd56cc21608992bf2c6f1f3dc5cf2572d0495c6a643b06c3a679f14
 F src/wal.h c3aa7825bfa2fe0d85bef2db94655f99870a285778baa36307c0a16da32b226a
-F src/walker.c 52fb58ff39452ef37e58bfa429a9ecb17e8ed3e9dda05912c0d869f80d3f4600
+F src/walker.c 6e540867a30d81e00205995fa2dc0e3d25365a7402251c9fd5d19aa4ff5e60b6
 F src/where.c 1c305bab0996a63219a6cb3d4718587f3a5dc5608120c4448985aa2bef88b7f5
 F src/whereInt.h 446e5e8018f83358ef917cf32d8e6a86dc8430113d0b17e720f1839d3faa44c4
 F src/wherecode.c 0e42f4ad53962e90349462520891734ed3217c7852f41c69ffac7a9eeaf31451
@@ -1913,7 +1913,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P bef2238de9550de84d4cd1c970a542b43db288d73d09a3c3ced7f98bb3188fd3
-R 9cdbf20427098ae8915fe3c4c7011236
+P 3e863cd09355abd80c1053d6d4dabb55841f806e3c418f923d67d36bf8313cb0
+R a2f252b041b1ce9ea09cc93be49d1068
 U drh
-Z 0ff14260d9ccebe4f6d06776ae79e9ce
+Z e9f9190f218ee2534b1576005539f8b4
diff --git a/manifest.uuid b/manifest.uuid
index f214941ac..df4ac25b6 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-3e863cd09355abd80c1053d6d4dabb55841f806e3c418f923d67d36bf8313cb0
\ No newline at end of file
+a61c0e6b78bd39f55464fafd257e68effded64995a66e8fa2d686e8c507ebe43
\ No newline at end of file
diff --git a/src/alter.c b/src/alter.c
index e9640d238..b68e18914 100644
--- a/src/alter.c
+++ b/src/alter.c
@@ -1575,7 +1575,7 @@ static int renameTableSelectCb(Walker *pWalker, Select *pSelect){
   RenameCtx *p = pWalker->u.pRename;
   SrcList *pSrc = pSelect->pSrc;
   if( pSelect->selFlags & SF_View ) return WRC_Prune;
-  if( pSrc==0 ){
+  if( NEVER(pSrc==0) ){
     assert( pWalker->pParse->db->mallocFailed );
     return WRC_Abort;
   }
diff --git a/src/build.c b/src/build.c
index ecc08f60f..5506d36de 100644
--- a/src/build.c
+++ b/src/build.c
@@ -4595,8 +4595,8 @@ SrcList *sqlite3SrcListAppend(
 void sqlite3SrcListAssignCursors(Parse *pParse, SrcList *pList){
   int i;
   SrcItem *pItem;
-  assert(pList || pParse->db->mallocFailed );
-  if( pList ){
+  assert( pList || pParse->db->mallocFailed );
+  if( ALWAYS(pList) ){
     for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
       if( pItem->iCursor>=0 ) continue;
       pItem->iCursor = pParse->nTab++;
diff --git a/src/expr.c b/src/expr.c
index d9c8af65c..bd45fbcd1 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1648,6 +1648,14 @@ Select *sqlite3SelectDup(sqlite3 *db, Select *pDup, int flags){
     if( p->pWin && db->mallocFailed==0 ) gatherSelectWindows(pNew);
 #endif
     pNew->selId = p->selId;
+    if( db->mallocFailed ){
+      /* Any prior OOM might have left the Select object incomplete.
+      ** Delete the whole thing rather than allow an incomplete Select
+      ** to be used by the code generator. */
+      pNew->pNext = 0;
+      sqlite3SelectDelete(db, pNew);
+      break;
+    }
     *pp = pNew;
     pp = &pNew->pPrior;
     pNext = pNew;
diff --git a/src/select.c b/src/select.c
index 92c2ecf8f..6a773202e 100644
--- a/src/select.c
+++ b/src/select.c
@@ -4207,7 +4207,7 @@ static int flattenSubquery(
       p->pPrior = pPrior;
     }else{
       pNew->selId = ++pParse->nSelect;
-      if( aCsrMap && db->mallocFailed==0 ){
+      if( aCsrMap && ALWAYS(db->mallocFailed==0) ){
         renumberCursors(pParse, pNew, iFrom, aCsrMap);
       }
       pNew->pPrior = pPrior;
diff --git a/src/walker.c b/src/walker.c
index 28c80fa79..e0acd5de2 100644
--- a/src/walker.c
+++ b/src/walker.c
@@ -164,7 +164,7 @@ int sqlite3WalkSelectFrom(Walker *pWalker, Select *p){
   SrcItem *pItem;
 
   pSrc = p->pSrc;
-  if( pSrc ){
+  if( ALWAYS(pSrc) ){
     for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
       if( pItem->pSelect && sqlite3WalkSelect(pWalker, pItem->pSelect) ){
         return WRC_Abort;