fix #4759

electrum/util.py

@@ -511,15 +511,21 @@ def format_satoshis(x, num_zeros=0, decimal_point=8, precision=None, is_diff=Fal
         return 'unknown'
     if precision is None:
         precision = decimal_point
+    # format string
     decimal_format = ".0" + str(precision) if precision > 0 else ""
     if is_diff:
         decimal_format = '+' + decimal_format
-    result = ("{:" + decimal_format + "f}").format(x / pow (10, decimal_point)).rstrip('0')
+    # initial result
+    scale_factor = pow(10, decimal_point)
+    result = ("{:" + decimal_format + "f}").format(Decimal(x) / scale_factor)
+    if "." not in result: result += "."
+    result = result.rstrip('0')
+    # extra decimal places
     integer_part, fract_part = result.split(".")
-    dp = DECIMAL_POINT
     if len(fract_part) < num_zeros:
         fract_part += "0" * (num_zeros - len(fract_part))
-    result = integer_part + dp + fract_part
+    result = integer_part + DECIMAL_POINT + fract_part
+    # leading/trailing whitespaces
     if whitespaces:
         result += " " * (decimal_point - len(fract_part))
         result = " " * (15 - len(result)) + result