Index: src/printf.c
==================================================================
--- src/printf.c
+++ src/printf.c
@@ -102,10 +102,17 @@
 /* Floating point constants used for rounding */
 static const double arRound[] = {
   5.0e-01, 5.0e-02, 5.0e-03, 5.0e-04, 5.0e-05,
   5.0e-06, 5.0e-07, 5.0e-08, 5.0e-09, 5.0e-10,
 };
+
+/* Return TRUE if a floating point number is negative, even a negative 0 */
+static int realIsNeg(double r){
+  i64 x;
+  memcpy(&x,&r,sizeof(x));
+  return x<0;
+}
 
 /*
 ** If SQLITE_OMIT_FLOATING_POINT is defined, then none of the floating point
 ** conversions will work.
 */
@@ -513,11 +520,11 @@
         }
 #ifdef SQLITE_OMIT_FLOATING_POINT
         length = 0;
 #else
         if( precision<0 ) precision = 6;         /* Set default precision */
-        if( realvalue<0.0 ){
+        if( realIsNeg(realvalue) ){
           realvalue = -realvalue;
           prefix = '-';
         }else{
           prefix = flag_prefix;
         }