Changes to sqlite3SelectNew() to work around a false-positive warning

from GCC-10.  The code is very slightly larger and slower as a result.

FossilOrigin-Name: 04e1edd8e5821a377407263829ed0d87968c708c9aeb1282107ea6f39a11c1cc

manifest

@@ -1,5 +1,5 @@
-C Innocuous\schanges\sto\shelp\sCoverity\savoid\sfalse-positives.
-D 2020-05-26T10:54:46.900
+C Changes\sto\ssqlite3SelectNew()\sto\swork\saround\sa\sfalse-positive\swarning\nfrom\sGCC-10.\s\sThe\scode\sis\svery\sslightly\slarger\sand\sslower\sas\sa\sresult.
+D 2020-05-26T11:10:25.934
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -533,7 +533,7 @@ F src/printf.c 94b5419ad0a17269f76a9e968ca19cf9fa37617abed2e246fc48844e511b6bc6
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c c2008519a0654f1e7490e9281ed0397d0f14bb840d81f0b96946248afcbdb25d
 F src/rowset.c ba9515a922af32abe1f7d39406b9d35730ed65efab9443dc5702693b60854c92
-F src/select.c e2a59548681bf1c407132863ae87bf2444aca5543867c21d9d09aa07f44aef5d
+F src/select.c 39a00a8bc89596dfb37c16afcbb1d33de5085b9963564b58aafe1566d08c0881
 F src/shell.c.in cf2d24f54412c06e5fb34af7fabc748651125e1dceac29b740e91f06d23447b6
 F src/sqlite.h.in 74342b41e9d68ff9e56b192009046f8dd0aa2bd76ce1a588f330de614ba61de7
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
@@ -1866,7 +1866,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 0c1fcf4711a2e66c813aed38cf41cd3e2123ee8eb6db98118086764c4ba83350
-R 85d34056e1232590b03a0479ee5fb897
+P 4ec8a5a203f10d228d0b3389120638766cc343179dbe38d5dbf69b650765934c d4bf60f464789935dc193ea99bf730c8fade448c7dca13eb3ce297965980f36e
+R 4b76e75897c43803d6dbedd7b8f1a56e
+T +closed d4bf60f464789935dc193ea99bf730c8fade448c7dca13eb3ce297965980f36e
 U drh
-Z 1828178303ff8f8ff8fc532baf643ec7
+Z d313ebf5bd4e6feaaa94a16cfe06a420

manifest.uuid

@@ -1 +1 @@
-4ec8a5a203f10d228d0b3389120638766cc343179dbe38d5dbf69b650765934c
+04e1edd8e5821a377407263829ed0d87968c708c9aeb1282107ea6f39a11c1cc

src/select.c

@@ -138,9 +138,9 @@ Select *sqlite3SelectNew(
   u32 selFlags,         /* Flag parameters, such as SF_Distinct */
   Expr *pLimit          /* LIMIT value.  NULL means not used */
 ){
-  Select *pNew;
+  Select *pNew, *pAllocated;
   Select standin;
-  pNew = sqlite3DbMallocRawNN(pParse->db, sizeof(*pNew) );
+  pAllocated = pNew = sqlite3DbMallocRawNN(pParse->db, sizeof(*pNew) );
   if( pNew==0 ){
     assert( pParse->db->mallocFailed );
     pNew = &standin;
@@ -174,12 +174,11 @@ Select *sqlite3SelectNew(
 #endif
   if( pParse->db->mallocFailed ) {
     clearSelect(pParse->db, pNew, pNew!=&standin);
-    pNew = 0;
+    pAllocated = 0;
   }else{
     assert( pNew->pSrc!=0 || pParse->nErr>0 );
   }
-  assert( pNew!=&standin );
-  return pNew;
+  return pAllocated;
 }