Fix for RoundPrecisionBug 2

Author: Joe7M

samples/distro-examples/tests/all.bas

@@ -140,7 +140,7 @@ print "DETERM:"' + DETERM (A, 1)
 print "DISCLOSE:" + DISCLOSE("{debraceme}", "{}")
 print "ENCLOSE:" + ENCLOSE ("braceme", "{}")
 print "EOF:"' + EOF (fileN)
-print "EXIST:"' + EXIST (file)
+print "EXIST:" + EXIST ("Makefile")
 print "EXP:" + EXP (x)
 print "FILES:"; FILES ("file-not-found")
 print "FIX:" + FIX (x)
@@ -246,3 +246,4 @@ print "WEEKDAY:" + WEEKDAY(dmy) + " " + WEEKDAY(1,1,2020) + " " + WEEKDAY(JULIAN
 print "XPOS:" + XPOS
 print "YPOS:" + YPOS
 print "RoundPrecisionBug:"; 32.99999999999999
+print "RoundPrecisionBug2:"; 64.1

samples/distro-examples/tests/output/all.out

@@ -123,7 +123,7 @@ DETERM:
 DISCLOSE:debraceme
 ENCLOSE:{braceme}
 EOF:
-EXIST:
+EXIST:1
 EXP:219695.9886721379
 FILES:[]
 FIX:13
@@ -229,3 +229,4 @@ WEEKDAY:-1 3 1
 XPOS:0
 YPOS:0
 RoundPrecisionBug:33
+RoundPrecisionBug2:64.1

src/common/fmt.c

@@ -20,16 +20,12 @@
 #define FMT_xMIN          1e-8
 #define FMT_xMAX          1e+14
 #define FMT_RND           14
-#define FMT_xRND          1e+14
-#define FMT_xRND2         1e+13
 #define FMT_MANTISSA_BITS 52
 #else
 // limits for use with 32bit integer algorithm
 #define FMT_xMIN          1e-8          // lowest limit to use the exp. format
 #define FMT_xMAX          1e+9          // highest limit to use the exp. format
 #define FMT_RND           9             // rounding on x digits
-#define FMT_xRND          1e+9          // 1 * 10 ^ FMT_RND
-#define FMT_xRND2         1e+8          // 1 * 10 ^ (FMT_RND-1)
 #define FMT_MANTISSA_BITS 23            // Bits of mantissa for 32bit float
 #endif
 
@@ -195,18 +191,13 @@ void bestfta_p(var_num_t x, char *dest, var_num_t minx, var_num_t maxx) {
   fptoa(ipart, buf);
   strcpy(d, buf);
   d += strlen(buf);
-
+  
   if (fpart > 0.0) {
     // format right part
     *d++ = '.';
+    fdif = fpart;
 
-    fdif = frac(x) * FMT_xRND;
-    if (fdif < fpart) {
-      // rounded value has greater precision
-      fdif = fpart;
-    }
-
-    while (fdif < FMT_xRND2) {
+    while (fdif < pow(10, precision - 1)) {
       fdif *= 10;
       *d++ = '0';
     }