msvcrt: New implementation of fcvt.

dlls/msvcrt/math.c

@@ -873,16 +873,81 @@ char * CDECL _ecvt( double number, int ndigits, int *decpt, int *sign )
 char * CDECL _fcvt( double number, int ndigits, int *decpt, int *sign )
 {
     thread_data_t *data = msvcrt_get_thread_data();
-    char *dec;
+    int stop, dec1, dec2;
+    char *ptr1, *ptr2, *first;
+    char buf[80]; /* ought to be enough */
 
     if (!data->efcvt_buffer)
         data->efcvt_buffer = MSVCRT_malloc( 80 ); /* ought to be enough */
 
-    snprintf(data->efcvt_buffer, 80, "%.*e", ndigits, number);
-    *sign = (number < 0);
-    dec = strchr(data->efcvt_buffer, '.');
-    *decpt = (dec) ? dec - data->efcvt_buffer : -1;
-    return data->efcvt_buffer;
+    if (number < 0)
+    {
+	*sign = 1;
+	number = -number;
+    } else *sign = 0;
+
+    snprintf(buf, 80, "%.*f", ndigits < 0 ? 0 : ndigits, number);
+    ptr1 = buf;
+    ptr2 = data->efcvt_buffer;
+    first = NULL;
+    dec1 = 0;
+    dec2 = 0;
+
+    /* For numbers below the requested resolution, work out where
+       the decimal point will be rather than finding it in the string */
+    if (number < 1.0 && number > 0.0) {
+	dec2 = log10(number + 1e-10);
+	if (-dec2 <= ndigits) dec2 = 0;
+    }
+
+    /* If requested digits is zero or less, we will need to truncate
+     * the returned string */
+    if (ndigits < 1) {
+	stop = strlen(buf) + ndigits;
+    } else {
+	stop = strlen(buf);
+    }
+
+    while (*ptr1 == '0') ptr1++; /* Skip leading zeroes */
+    while (*ptr1 != '\0' && *ptr1 != '.') {
+	if (!first) first = ptr2;
+	if ((ptr1 - buf) < stop) {
+	    *ptr2++ = *ptr1++;
+	} else {
+	    ptr1++;
+	}
+	dec1++;
+    }
+
+    if (ndigits > 0) {
+	ptr1++;
+	if (!first) {
+	    while (*ptr1 == '0') { /* Process leading zeroes */
+		*ptr2++ = *ptr1++;
+		dec1--;
+	    }
+	}
+	while (*ptr1 != '\0') {
+	    if (!first) first = ptr2;
+	    *ptr2++ = *ptr1++;
+	}
+    }
+
+    *ptr2 = '\0';
+
+    /* We never found a non-zero digit, then our number is either
+     * smaller than the requested precision, or 0.0 */
+    if (!first) {
+	if (number > 0.0) {
+	    first = ptr2;
+	} else {
+	    first = data->efcvt_buffer;
+	    dec1 = 0;
+	}
+    }
+
+    *decpt = dec2 ? dec2 : dec1;
+    return first;
 }
 
 /***********************************************************************

dlls/msvcrt/tests/printf.c

@@ -552,47 +552,96 @@ static void test_fcvt(void)
     char *str;
     int dec=100, sign=100;
     
+    /* Numbers less than 1.0 with different precisions */
     str = _fcvt(0.0001, 1, &dec, &sign );
-    todo_wine {
-    ok( 0 == strcmp(str,""), "bad return\n");
-    ok( -3 == dec, "dec wrong\n");
-    }
-    ok( 0 == sign, "dec wrong\n");
+    ok( 0 == strcmp(str,""), "bad return '%s'\n", str);
+    ok( -3 == dec, "dec wrong %d\n", dec);
+    ok( 0 == sign, "sign wrong\n");
 
     str = _fcvt(0.0001, -10, &dec, &sign );
-    todo_wine {
-    ok( 0 == strcmp(str,""), "bad return\n");
-    ok( -3 == dec, "dec wrong\n");
-    }
-    ok( 0 == sign, "dec wrong\n");
+    ok( 0 == strcmp(str,""), "bad return '%s'\n", str);
+    ok( -3 == dec, "dec wrong %d\n", dec);
+    ok( 0 == sign, "sign wrong\n");
 
     str = _fcvt(0.0001, 10, &dec, &sign );
-    todo_wine {
-    ok( 0 == strcmp(str,"1000000"), "bad return\n");
-    ok( -3 == dec, "dec wrong\n");
-    }
-    ok( 0 == sign, "dec wrong\n");
+    ok( 0 == strcmp(str,"1000000"), "bad return '%s'\n", str);
+    ok( -3 == dec, "dec wrong %d\n", dec);
+    ok( 0 == sign, "sign wrong\n");
 
+    /* Basic sign test */
     str = _fcvt(-111.0001, 5, &dec, &sign );
-    todo_wine {
-    ok( 0 == strcmp(str,"11100010"), "bad return\n");
-    ok( 3 == dec, "dec wrong\n");
-    }
-    ok( 1 == sign, "dec wrong\n");
+    ok( 0 == strcmp(str,"11100010"), "bad return '%s'\n", str);
+    ok( 3 == dec, "dec wrong %d\n", dec);
+    ok( 1 == sign, "sign wrong\n");
 
     str = _fcvt(111.0001, 5, &dec, &sign );
-    todo_wine {
-    ok( 0 == strcmp(str,"11100010"), "bad return\n");
+    ok( 0 == strcmp(str,"11100010"), "bad return '%s'\n", str);
     ok( 3 == dec, "dec wrong\n");
-    }
-    ok( 0 == sign, "dec wrong\n");
+    ok( 0 == sign, "sign wrong\n");
 
+    /* 0.0 with different precisions */
     str = _fcvt(0.0, 5, &dec, &sign );
-    todo_wine {
-    ok( 0 == strcmp(str,"00000"), "bad return\n");
-    ok( 0 == dec, "dec wrong\n");
-    }
-    ok( 0 == sign, "dec wrong\n");
+    ok( 0 == strcmp(str,"00000"), "bad return '%s'\n", str);
+    ok( 0 == dec, "dec wrong %d\n", dec);
+    ok( 0 == sign, "sign wrong\n");
+
+    str = _fcvt(0.0, 0, &dec, &sign );
+    ok( 0 == strcmp(str,""), "bad return '%s'\n", str);
+    ok( 0 == dec, "dec wrong %d\n", dec);
+    ok( 0 == sign, "sign wrong\n");
+
+    str = _fcvt(0.0, -1, &dec, &sign );
+    ok( 0 == strcmp(str,""), "bad return '%s'\n", str);
+    ok( 0 == dec, "dec wrong %d\n", dec);
+    ok( 0 == sign, "sign wrong\n");
+
+    /* Numbers > 1.0 with 0 or -ve precision */
+    str = _fcvt(-123.0001, 0, &dec, &sign );
+    ok( 0 == strcmp(str,"123"), "bad return '%s'\n", str);
+    ok( 3 == dec, "dec wrong %d\n", dec);
+    ok( 1 == sign, "sign wrong\n");
+
+    str = _fcvt(-123.0001, -1, &dec, &sign );
+    ok( 0 == strcmp(str,"12"), "bad return '%s'\n", str);
+    ok( 3 == dec, "dec wrong %d\n", dec);
+    ok( 1 == sign, "sign wrong\n");
+
+    str = _fcvt(-123.0001, -2, &dec, &sign );
+    ok( 0 == strcmp(str,"1"), "bad return '%s'\n", str);
+    ok( 3 == dec, "dec wrong %d\n", dec);
+    ok( 1 == sign, "sign wrong\n");
+
+    str = _fcvt(-123.0001, -3, &dec, &sign );
+    ok( 0 == strcmp(str,""), "bad return '%s'\n", str);
+    ok( 3 == dec, "dec wrong %d\n", dec);
+    ok( 1 == sign, "sign wrong\n");
+
+    /* Numbers > 1.0, but with rounding at the point of precision */
+    str = _fcvt(99.99, 1, &dec, &sign );
+    ok( 0 == strcmp(str,"1000"), "bad return '%s'\n", str);
+    ok( 3 == dec, "dec wrong %d\n", dec);
+    ok( 0 == sign, "sign wrong\n");
+
+    /* Numbers < 1.0 where rounding occurs at the point of precision */
+    str = _fcvt(0.00636, 2, &dec, &sign );
+    ok( 0 == strcmp(str,"1"), "bad return '%s'\n", str);
+    ok( -1 == dec, "dec wrong %d\n", dec);
+    ok( 0 == sign, "sign wrong\n");
+
+    str = _fcvt(0.00636, 3, &dec, &sign );
+    ok( 0 == strcmp(str,"6"), "bad return '%s'\n", str);
+    ok( -2 == dec, "dec wrong %d\n", dec);
+    ok( 0 == sign, "sign wrong\n");
+
+    str = _fcvt(0.09999999996, 2, &dec, &sign );
+    ok( 0 == strcmp(str,"10"), "bad return '%s'\n", str);
+    ok( 0 == dec, "dec wrong %d\n", dec);
+    ok( 0 == sign, "sign wrong\n");
+
+    str = _fcvt(0.6, 0, &dec, &sign );
+    ok( 0 == strcmp(str,"1"), "bad return '%s'\n", str);
+    ok( 1 == dec, "dec wrong %d\n", dec);
+    ok( 0 == sign, "sign wrong\n");
 }
 
 START_TEST(printf)