Disable the optimization where a REAL value with no fractional part

is stored as an INTEGER when the integer uses as much space as the real
value it proposes to stand in for (8 bytes).  This avoids corner cases
of comparing integers against real values that are beyond the resolution
of an IEEE 754 double.  Fix for ticket [6c1d3febc00b22d457c78c2]

FossilOrigin-Name: 9b0915272f4d4052aa31e9297424a7db9a0234b676e8e2a44c3f2dc54236705a

manifest

@@ -1,5 +1,5 @@
-C Avoid\slong\sdelays\sthat\scan\soccur\swhen\s".recover"ing\sdata\sfrom\sa\sdatabase\swith\sa\scorrupt\sfreelist.
-D 2019-05-09T16:57:39.190
+C Disable\sthe\soptimization\swhere\sa\sREAL\svalue\swith\sno\sfractional\spart\nis\sstored\sas\san\sINTEGER\swhen\sthe\sinteger\suses\sas\smuch\sspace\sas\sthe\sreal\nvalue\sit\sproposes\sto\sstand\sin\sfor\s(8\sbytes).\s\sThis\savoids\scorner\scases\nof\scomparing\sintegers\sagainst\sreal\svalues\sthat\sare\sbeyond\sthe\sresolution\nof\san\sIEEE\s754\sdouble.\s\sFix\sfor\sticket\s[6c1d3febc00b22d457c78c2]
+D 2019-05-09T17:10:30.104
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -597,7 +597,7 @@ F src/vdbe.c d4efd6e5ecff8eeef280ce5d622dc2c0cfe085014e5813401b346517574adb18
 F src/vdbe.h 712bca562eaed1c25506b9faf9680bdc75fc42e2f4a1cd518d883fa79c7a4237
 F src/vdbeInt.h 3ba14553508d66f58753952d6dd287dce4ec735de02c6440858b4891aed51c17
 F src/vdbeapi.c f9161e5c77f512fbb80091ce8af621d19c9556bda5e734cffaac1198407400da
-F src/vdbeaux.c f9fb1f71e216850267744fde8a6a0b2d3822235d6f85568af368be4722e8da13
+F src/vdbeaux.c d444f4a3ff9c571965329a186701a57fe445e4c3f4c42f87402aca75386ba358
 F src/vdbeblob.c f5c70f973ea3a9e915d1693278a5f890dc78594300cf4d54e64f2b0917c94191
 F src/vdbemem.c b76b42ac9d6a36fc55a0797929fc94cc33e1334eea2792f5ee1eef868ce13320
 F src/vdbesort.c 66592d478dbb46f19aed0b42222325eadb84deb40a90eebe25c6e7c1d8468f47
@@ -1275,7 +1275,7 @@ F test/securedel.test 2f70b2449186a1921bd01ec9da407fbfa98c3a7a5521854c300c194b2f
 F test/securedel2.test 2d54c28e46eb1fd6902089958b20b1b056c6f1c5
 F test/select1.test 7d41f354998524070317207d4e2b68e725e4cf14a57835fc746d4bea686a8714
 F test/select2.test 352480e0e9c66eda9c3044e412abdf5be0215b56
-F test/select3.test 2ce595f8fb8e2ac10071d3b4e424cadd4634a054
+F test/select3.test 3905450067c28766bc83ee397f6d87342de868baa60f2bcfd00f286dfbd62cb9
 F test/select4.test 5389d9895968d1196c457d59b3ee6515d771d328
 F test/select5.test df9ec0d218cedceb4fe7b63262025b547b50a55e59148c6f40b60ca25f1d4546
 F test/select6.test 39eac4a5c03650b2b473c532882273283ee8b7a0
@@ -1825,7 +1825,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P ac790729d9c8f8612936bab56dca6061408007bc2150ac8c7089132403d7f885
-R 6e5edbee3c41d65385191dd600b1b4bf
-U dan
-Z 90af5c9a4f9287285acd46f3e2e8c7ab
+P 20f06bf2e659212a68dcf138e444da7bd4220548ec15a97cfd7eb82e028b3630
+R 1e923a6ef9e14ab60fd1515804aac862
+U drh
+Z c06fe0d1d976fd970296d42fc604ced0

manifest.uuid

@@ -1 +1 @@
-20f06bf2e659212a68dcf138e444da7bd4220548ec15a97cfd7eb82e028b3630
+9b0915272f4d4052aa31e9297424a7db9a0234b676e8e2a44c3f2dc54236705a

src/vdbeaux.c

@@ -3422,6 +3422,8 @@ int sqlite3VdbeCursorMoveto(VdbeCursor **pp, int *piCol){
 
 /*
 ** Return the serial-type for the value stored in pMem.
+**
+** This routine might convert a large MEM_IntReal value into MEM_Real.
 */
 u32 sqlite3VdbeSerialType(Mem *pMem, int file_format, u32 *pLen){
   int flags = pMem->flags;
@@ -3458,6 +3460,15 @@ u32 sqlite3VdbeSerialType(Mem *pMem, int file_format, u32 *pLen){
     if( u<=2147483647 ){ *pLen = 4; return 4; }
     if( u<=MAX_6BYTE ){ *pLen = 6; return 5; }
     *pLen = 8;
+    if( flags&MEM_IntReal ){
+      /* If the value is IntReal and is going to take up 8 bytes to store
+      ** as an integer, then we might as well make it an 8-byte floating
+      ** point value */
+      pMem->u.r = (double)pMem->u.i;
+      pMem->flags &= ~MEM_IntReal;
+      pMem->flags |= MEM_Real;
+      return 7;
+    }
     return 6;
   }
   if( flags&MEM_Real ){

test/select3.test

@@ -261,4 +261,49 @@ do_test select3-8.2 {
   }
 } {real}
 
+# 2019-05-09 ticket https://www.sqlite.org/src/tktview/6c1d3febc00b22d457c7
+#
+unset -nocomplain x
+foreach {id x} {
+  100 127
+  101 128
+  102 -127
+  103 -128
+  104 -129
+  110 32767
+  111 32768
+  112 -32767
+  113 -32768
+  114 -32769
+  120 2147483647
+  121 2147483648
+  122 -2147483647
+  123 -2147483648
+  124 -2147483649
+  130 140737488355327
+  131 140737488355328
+  132 -140737488355327
+  133 -140737488355328
+  134 -140737488355329
+  140 9223372036854775807
+  141 -9223372036854775807
+  142 -9223372036854775808
+  143 9223372036854775806
+  144 9223372036854775805
+  145 -9223372036854775806
+  146 -9223372036854775805
+
+} {
+  set x [expr {$x+0}]
+  do_execsql_test select3-8.$id {
+     DROP TABLE IF EXISTS t1;
+     CREATE TABLE t1 (c0, c1 REAL PRIMARY KEY);
+     INSERT INTO t1(c0, c1) VALUES (0, $x), (0, 0);
+     UPDATE t1 SET c0 = NULL;
+     UPDATE OR REPLACE t1 SET c1 = 1;
+     SELECT DISTINCT * FROM t1 WHERE (t1.c0 IS NULL);
+     PRAGMA integrity_check;
+  } {{} 1.0 ok}
+}
+
 finish_test