fix: display fraction for integer values with mandatory 0 placeholder (#3625)

tests/data/Style/NumberFormatFractions.php

@@ -143,4 +143,22 @@ return [
         2.65,
         '# ???/12',
     ],
+    // Integer value, fraction format (issue #3625): a mandatory-digit (0)
+    // numerator still displays the fraction, while ? and # placeholders
+    // suppress it and leave only the integer.
+    [
+        '1/1',
+        1,
+        '0/0',
+    ],
+    [
+        '1 0/1',
+        1,
+        '0 0/0',
+    ],
+    [
+        '1',
+        1,
+        '? ??/???',
+    ],
 ];