Proof that a null precision is valid:
------------------------------- foo.d -------------------------------
import std.stdio;
import std.format;
void main () { writeln (format ("%.f", 3.
1415926)); }
---------------------------------------------------------------------
* gettext-tools/tests/format-d-1: Add a test case with null precision.
"abc%,*0g"
# Invalid: precision after separator
"abc%,4.2g"
+# Valid: null precision
+"abc%.f"
# Invalid: twice precision
"abc%.4.2g"
# Invalid: twice separator