remove problematic bigint optimisation (#987)

Author: pjfanning

src/main/java/com/fasterxml/jackson/core/io/NumberInput.java

@@ -14,13 +14,6 @@
  */
 public final class NumberInput
 {
-    // numbers with more than these characters are better parsed with BigDecimalParser
-    // parsing numbers with many digits in Java is slower than O(n)
-
-    // 04-Apr-2023, tatu: NOTE! This is above default "longest number by chars"
-    //   limit
-    private final static int LARGE_INT_SIZE = 1250;
-
     /**
      * Formerly used constant for a value that was problematic on certain
      * pre-1.8 JDKs.
@@ -496,9 +489,6 @@ public static BigDecimal parseBigDecimal(final char[] ch, final boolean useFastP
      * @since v2.14
      */
     public static BigInteger parseBigInteger(final String s) throws NumberFormatException {
-        if (s.length() > LARGE_INT_SIZE) {
-            return BigDecimalParser.parse(s).toBigInteger();
-        }
         return new BigInteger(s);
     }
 

src/test/java/com/fasterxml/jackson/core/io/BigIntegerParserTest.java

@@ -2,6 +2,16 @@
 
 public class BigIntegerParserTest extends com.fasterxml.jackson.core.BaseTest {
 
+    public void testFastParseBigIntegerFailsWithENotation() {
+        String num = "2e308";
+        try {
+            BigIntegerParser.parseWithFastParser(num);
+            fail("expected NumberFormatException");
+        } catch (NumberFormatException nfe) {
+            // expected
+        }
+    }
+
     public void testLongStringFastParseBigInteger() {
         try {
             BigIntegerParser.parseWithFastParser(genLongString());