[fastserde] Fix issue with generating schema fingerprint

when NaN is a default value.

fastserde/avro-fastserde-tests-common/src/test/avro/floatWithDefaultNaN.avsc

@@ -0,0 +1,13 @@
+{
+  "type": "record",
+  "name": "FloatWithDefaultNaN",
+  "namespace": "com.linkedin.avro.fastserde.generated.avro",
+  "doc": "Used to verify Utils.getSchemaFingerprint() method",
+  "fields": [
+    {
+      "name": "floatWithDefaultNaN",
+      "type": "float",
+      "default": "NaN"
+    }
+  ]
+}

fastserde/avro-fastserde-tests-common/src/test/java/com/linkedin/avro/fastserde/UtilsTest.java

@@ -3,11 +3,34 @@
 import org.testng.Assert;
 import org.testng.annotations.Test;
 
+import com.linkedin.avro.fastserde.generated.avro.FloatWithDefaultNaN;
+
 
 public class UtilsTest {
 
   @Test (groups = "deserializationTest")
   public void testGenerateSourcePathFromPackageName() {
     Assert.assertEquals(Utils.generateSourcePathFromPackageName("com.linkedin.avro"), Utils.fixSeparatorsToMatchOS("/com/linkedin/avro/"));
   }
+
+  @Test
+  void testDefaultValueNaN() {
+    // given
+    FloatWithDefaultNaN floatWithDefaultNaN = FloatWithDefaultNaN.newBuilder().build();
+
+    // when
+    float defaultValue = floatWithDefaultNaN.getFloatWithDefaultNaN();
+
+    // then
+    Assert.assertTrue(Float.isNaN(defaultValue));
+  }
+
+  @Test
+  void testFingerprintOfSchemaWithDefaultNaN() {
+    // when
+    int schemaFingerprint = Utils.getSchemaFingerprint(FloatWithDefaultNaN.SCHEMA$);
+
+    // then
+    Assert.assertEquals(schemaFingerprint, 502051122);
+  }
 }

helper/helper-common/src/main/java/com/linkedin/avroutil1/compatibility/Jackson2Utils.java

@@ -143,20 +143,19 @@ public static boolean isRoundNumber(JsonNode node) {
    *  Enforces uniform numeric default values across Avro versions
    */
   public static JsonNode enforceUniformNumericDefaultValues(Schema.Field field, JsonNode genericDefaultValue) {
-    BigDecimal numericDefaultValue = genericDefaultValue.decimalValue();
     Schema schema = field.schema();
     // a default value for a union, must match the first element of the union
     Schema.Type defaultType = schema.getType() == UNION ? schema.getTypes().get(0).getType() : schema.getType();
 
     switch (defaultType) {
       case INT:
-        if (!isAMathematicalInteger(numericDefaultValue)) {
+        if (!isAMathematicalInteger(genericDefaultValue.decimalValue())) {
           LOGGER.warn(String.format("Invalid default value: %s for \"int\" field: %s", genericDefaultValue, field.name()));
           return genericDefaultValue;
         }
         return new IntNode(genericDefaultValue.intValue());
       case LONG:
-        if (!isAMathematicalInteger(numericDefaultValue)) {
+        if (!isAMathematicalInteger(genericDefaultValue.decimalValue())) {
           LOGGER.warn(String.format("Invalid default value: %s for \"long\" field: %s", genericDefaultValue, field.name()));
           return genericDefaultValue;
         }