Enhance the sqlite3GetTempRange() and sqlite3ReleaseTempRange() internal

routines so that they use sqlite3GetTempReg() and sqlite3ReleaseTempReg()
when nReg==1.

FossilOrigin-Name: 4071da2f87a2f24a279ac3bced8c794ad374b47c

manifest

@@ -1,5 +1,5 @@
-C Fix\sa\stypo\sin\sa\scomment\sin\sexpr.c.
-D 2016-09-06T12:04:50.217
+C Enhance\sthe\ssqlite3GetTempRange()\sand\ssqlite3ReleaseTempRange()\sinternal\nroutines\sso\sthat\sthey\suse\ssqlite3GetTempReg()\sand\ssqlite3ReleaseTempReg()\nwhen\snReg==1.
+D 2016-09-06T14:37:05.419
 F Makefile.in cfd8fb987cd7a6af046daa87daa146d5aad0e088
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 5017381e4853b1472e01d5bb926be1268eba429c
@@ -338,7 +338,7 @@ F src/ctime.c e77f3dc297b4b65c96da78b4ae4272fdfae863d7
 F src/date.c 95c9a8d00767e7221a8e9a31f4e913fc8029bf6b
 F src/dbstat.c 19ee7a4e89979d4df8e44cfac7a8f905ec89b77d
 F src/delete.c 76c084f0265f4a3cd1ecf17eee112a94f1ccbc05
-F src/expr.c 17af5dc7326543ce395503adc1b88b0a722fcee3
+F src/expr.c 4c2b9886927fb6628560ad40d14b04946d71abbd
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c e2be0968c1adc679c87e467aa5b4f167588f38a8
 F src/func.c 29cc9acb170ec1387b9f63eb52cd85f8de96c771
@@ -385,7 +385,7 @@ F src/printf.c a5f0ca08ddede803c241266abb46356ec748ded1
 F src/random.c ba2679f80ec82c4190062d756f22d0c358180696
 F src/resolve.c 24f40fd0c3475821d1ad762a3f2c3455cc839b42
 F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
-F src/select.c 38216d0b2d42a0f475abf86a84c3499e6421ba29
+F src/select.c 4ccfc554a2d2313b0ac364120b1db9b74c41b248
 F src/shell.c 79dda477be6c96eba6e952a934957ad36f87acc7
 F src/sqlite.h.in 4a030e254e204570444b34bf7d40fb4a5416089e
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
@@ -1522,7 +1522,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P e8f105c3009e9b667db2afc0088b020a2b94d370
-R 48ea3338c1b6c2a2aac4971ca7c78062
-U dan
-Z 231ae31b564ec961477419ce2ce3ecda
+P 288e934f356ff6276b3e7581ac0f998ca6e93610
+R 373bd5ec1c7378267f0ce69533be2f50
+U drh
+Z c12fde59fd4c6cc2e37d73169853128b

manifest.uuid

@@ -1 +1 @@
-288e934f356ff6276b3e7581ac0f998ca6e93610
+4071da2f87a2f24a279ac3bced8c794ad374b47c

src/expr.c

@@ -4991,10 +4991,11 @@ void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
 }
 
 /*
-** Allocate or deallocate a block of nReg consecutive registers
+** Allocate or deallocate a block of nReg consecutive registers.
 */
 int sqlite3GetTempRange(Parse *pParse, int nReg){
   int i, n;
+  if( nReg==1 ) return sqlite3GetTempReg(pParse);
   i = pParse->iRangeReg;
   n = pParse->nRangeReg;
   if( nReg<=n ){
@@ -5008,6 +5009,10 @@ int sqlite3GetTempRange(Parse *pParse, int nReg){
   return i;
 }
 void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
+  if( nReg==1 ){
+    sqlite3ReleaseTempReg(pParse, iReg);
+    return;
+  }
   sqlite3ExprCacheRemove(pParse, iReg, nReg);
   if( nReg>pParse->nRangeReg ){
     pParse->nRangeReg = nReg;

src/select.c

@@ -1222,14 +1222,10 @@ static void generateSortTail(
     regRowid = 0;
     regRow = pDest->iSdst;
     nSortData = nColumn;
-  }else if( eDest==SRT_Set ){
+  }else{
     regRowid = sqlite3GetTempReg(pParse);
     regRow = sqlite3GetTempRange(pParse, nColumn);
     nSortData = nColumn;
-  }else{
-    regRowid = sqlite3GetTempReg(pParse);
-    regRow = sqlite3GetTempReg(pParse);
-    nSortData = 1;
   }
   nKey = pOrderBy->nExpr - pSort->nOBSat;
   if( pSort->sortFlags & SORTFLAG_UseSorter ){