Merge #1010: Match against an optional single trailing colon

88ce8fe Match against an optional single trailing colon (Tobin C. Harding)

Pull request description:

  Currently we allow multiple trailing colons when matching within the
  `check_format_non_negative` macro. We can be more restrictive with no
  loss of usability.

  Use `$(;)?` instead of `$(;)*` to match against 0 or 1 semi-colons
  instead of 0 or more.

  Done as part of the [edition 2018 checklist](#510).

ACKs for top commit:
  Kixunil:
    ACK 88ce8fe
  apoelstra:
    ACK 88ce8fe

Tree-SHA512: 4409c094f6a0aa49ddebdad850fd1d5a31a57dae8828f5a1db0ee5a855e1bce9e43aea69fa0b4d132068c3a43f1f62d35409b9ac5b32ed876e4dd586829e8e68

src/util/amount.rs

@@ -1640,7 +1640,7 @@ mod tests {
 
     // Creates individual test functions to make it easier to find which check failed.
     macro_rules! check_format_non_negative {
-        ($denom:ident; $($test_name:ident, $val:expr, $format_string:expr, $expected:expr);* $(;)*) => {
+        ($denom:ident; $($test_name:ident, $val:expr, $format_string:expr, $expected:expr);* $(;)?) => {
             $(
                 #[test]
                 fn $test_name() {
@@ -1652,7 +1652,7 @@ mod tests {
     }
 
     macro_rules! check_format_non_negative_show_denom {
-        ($denom:ident, $denom_suffix:expr; $($test_name:ident, $val:expr, $format_string:expr, $expected:expr);* $(;)*) => {
+        ($denom:ident, $denom_suffix:expr; $($test_name:ident, $val:expr, $format_string:expr, $expected:expr);* $(;)?) => {
             $(
                 #[test]
                 fn $test_name() {