Index: src/func.c
==================================================================
--- src/func.c
+++ src/func.c
@@ -861,12 +861,23 @@
 */
 static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
   assert( argc==1 );
   UNUSED_PARAMETER(argc);
   switch( sqlite3_value_type(argv[0]) ){
-    case SQLITE_INTEGER:
     case SQLITE_FLOAT: {
+      double r1, r2;
+      char zBuf[50];
+      r1 = sqlite3_value_double(argv[0]);
+      sqlite3_snprintf(sizeof(zBuf), zBuf, "%!.15g", r1);
+      sqlite3AtoF(zBuf, &r2, 20, SQLITE_UTF8);
+      if( r1!=r2 ){
+        sqlite3_snprintf(sizeof(zBuf), zBuf, "%!.20e", r1);
+      }
+      sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
+      break;
+    }
+    case SQLITE_INTEGER: {
       sqlite3_result_value(context, argv[0]);
       break;
     }
     case SQLITE_BLOB: {
       char *zText = 0;

Index: src/printf.c
==================================================================
--- src/printf.c
+++ src/printf.c
@@ -122,11 +122,12 @@
 ** always returned.
 */
 static char et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
   int digit;
   LONGDOUBLE_TYPE d;
-  if( (*cnt)++ >= 16 ) return '0';
+  if( (*cnt)<=0 ) return '0';
+  (*cnt)--;
   digit = (int)*val;
   d = digit;
   digit += '0';
   *val = (*val - d)*10.0;
   return (char)digit;
@@ -426,13 +427,16 @@
           bufpt = "NaN";
           length = 3;
           break;
         }
         if( realvalue>0.0 ){
-          while( realvalue>=1e32 && exp<=350 ){ realvalue *= 1e-32; exp+=32; }
-          while( realvalue>=1e8 && exp<=350 ){ realvalue *= 1e-8; exp+=8; }
-          while( realvalue>=10.0 && exp<=350 ){ realvalue *= 0.1; exp++; }
+          LONGDOUBLE_TYPE scale = 1.0;
+          while( realvalue>=1e100*scale && exp<=350 ){ scale *= 1e100;exp+=100;}
+          while( realvalue>=1e64*scale && exp<=350 ){ scale *= 1e64; exp+=64; }
+          while( realvalue>=1e8*scale && exp<=350 ){ scale *= 1e8; exp+=8; }
+          while( realvalue>=10.0*scale && exp<=350 ){ scale *= 10.0; exp++; }
+          realvalue /= scale;
           while( realvalue<1e-8 ){ realvalue *= 1e8; exp-=8; }
           while( realvalue<1.0 ){ realvalue *= 10.0; exp--; }
           if( exp>350 ){
             if( prefix=='-' ){
               bufpt = "-Inf";
@@ -461,11 +465,11 @@
           }else{
             precision = precision - exp;
             xtype = etFLOAT;
           }
         }else{
-          flag_rtz = 0;
+          flag_rtz = flag_altform2;
         }
         if( xtype==etEXP ){
           e2 = 0;
         }else{
           e2 = exp;
@@ -476,11 +480,11 @@
             pAccum->mallocFailed = 1;
             return;
           }
         }
         zOut = bufpt;
-        nsd = 0;
+        nsd = 16 + flag_altform2*10;
         flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;
         /* The sign in front of the number */
         if( prefix ){
           *(bufpt++) = prefix;
         }

Index: src/test_config.c
==================================================================
--- src/test_config.c
+++ src/test_config.c
@@ -614,10 +614,25 @@
   {
     static const int cv_TEMP_STORE = SQLITE_TEMP_STORE;
     Tcl_LinkVar(interp, "TEMP_STORE", (char *)&(cv_TEMP_STORE),
                 TCL_LINK_INT | TCL_LINK_READ_ONLY);
   }
+
+#ifdef _MSC_VER
+  {
+    static const int cv__MSC_VER = 1;
+    Tcl_LinkVar(interp, "_MSC_VER", (char *)&(cv__MSC_VER),
+                TCL_LINK_INT | TCL_LINK_READ_ONLY);
+  }
+#endif
+#ifdef __GNUC__
+  {
+    static const int cv___GNUC__ = 1;
+    Tcl_LinkVar(interp, "__GNUC__", (char *)&(cv___GNUC__),
+                TCL_LINK_INT | TCL_LINK_READ_ONLY);
+  }
+#endif
 }
 
 
 /*
 ** Register commands with the TCL interpreter.

Index: test/atof1.test
==================================================================
--- test/atof1.test
+++ test/atof1.test
@@ -12,24 +12,48 @@
 # Tests of the sqlite3AtoF() function.
 #
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
+
+if {![info exists __GNUC__]} {
+  finish_test
+  return
+}
 
 expr srand(1)
-for {set i 1} {$i<10000} {incr i} {
-  do_test 1.$i {
-    set pow [expr {int((rand()-0.5)*100)}]
-    set x [expr {pow((rand()-0.5)*2*rand(),$pow)}]
-    set xf [format %.45e $x]
+for {set i 1} {$i<20000} {incr i} {
+  set pow [expr {int((rand()-0.5)*100)}]
+  set x [expr {pow((rand()-0.5)*2*rand(),$pow)}]
+  set xf [format %.32e $x]
+
+  # Verify that text->real conversions get exactly same ieee754 floating-
+  # point value in SQLite as they do in TCL.
+  #
+  do_test atof1-1.$i.1 {
     set y [db eval "SELECT $xf=\$x"]
     if {!$y} {
       puts -nonewline \173[db eval "SELECT real2hex($xf), real2hex(\$x)"]\175
       db eval "SELECT $xf+0.0 AS a, \$x AS b" {
         puts [format "\n%.60e\n%.60e\n%.60e" $x $a $b]
       }
     }
+    set y
+  } {1}
+
+  # Verify that round-trip real->text->real conversions using the quote()
+  # function preserve the bits of the numeric value exactly.
+  #
+  do_test atof1-1.$i.2 {
+    set y [db eval {SELECT $x=CAST(quote($x) AS real)}]
+    if {!$y} {
+      db eval {SELECT real2hex($x) a, real2hex(CAST(quote($x) AS real)) b} {}
+      puts "\nIN:    $a $xf"
+      puts [format {QUOTE: %16s %s} {} [db eval {SELECT quote($x)}]]
+      db eval {SELECT CAST(quote($x) AS real) c} {}
+      puts "OUT:   $b [format %.32e $c]"
+    }
     set y
   } {1}
 }
 
 

Index: test/date.test
==================================================================
--- test/date.test
+++ test/date.test
@@ -149,11 +149,11 @@
 datetest 3.1 {strftime('%d','2003-10-31 12:34:56.432')} 31
 datetest 3.2.1 {strftime('pre%fpost','2003-10-31 12:34:56.432')} pre56.432post
 datetest 3.2.2 {strftime('%f','2003-10-31 12:34:59.9999999')} 59.999
 datetest 3.3 {strftime('%H','2003-10-31 12:34:56.432')} 12
 datetest 3.4 {strftime('%j','2003-10-31 12:34:56.432')} 304
-datetest 3.5 {strftime('%J','2003-10-31 12:34:56.432')} 2452944.02426426
+datetest 3.5 {strftime('%J','2003-10-31 12:34:56.432')} 2452944.024264259
 datetest 3.6 {strftime('%m','2003-10-31 12:34:56.432')} 10
 datetest 3.7 {strftime('%M','2003-10-31 12:34:56.432')} 34
 datetest 3.8.1 {strftime('%s','2003-10-31 12:34:56.432')} 1067603696
 datetest 3.8.2 {strftime('%s','2038-01-19 03:14:07')} 2147483647
 datetest 3.8.3 {strftime('%s','2038-01-19 03:14:08')} 2147483648

Index: test/func.test
==================================================================
--- test/func.test
+++ test/func.test
@@ -310,11 +310,11 @@
   } {99999999999995.0}
   do_test func-4.37 {
     execsql {SELECT round(9999999999999.55,1);}
   } {9999999999999.6}
   do_test func-4.38 {
-    execsql {SELECT round(9999999999999.555,2);}
+    execsql {SELECT round(9999999999999.556,2);}
   } {9999999999999.56}
 }
 
 # Test the upper() and lower() functions
 #