From f099a5f8eb3c9db19047e7059f13142b1210b5be Mon Sep 17 00:00:00 2001
From: shoothzj <shoothzj@gmail.com>
Date: Thu, 12 Aug 2021 16:28:06 +0800
Subject: [PATCH] Fix the incorrect double compare with e,E+,e+

---
 .../minidev/json/parser/JSONParserBase.java   | 35 +++++++++++++++++--
 .../json/test/TestBigDigitUnrestricted.java   |  2 +-
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/json-smart/src/main/java/net/minidev/json/parser/JSONParserBase.java b/json-smart/src/main/java/net/minidev/json/parser/JSONParserBase.java
index afafd72..5a0e67f 100644
--- a/json-smart/src/main/java/net/minidev/json/parser/JSONParserBase.java
+++ b/json-smart/src/main/java/net/minidev/json/parser/JSONParserBase.java
@@ -148,14 +148,16 @@ protected Number extractFloat() throws ParseException {
 
 			// follow JSonIJ parsing method
 			if (xs.length() > 18) {
-				BigDecimal big = new BigDecimal(xs);
 				// use extra CPU to check if the result can be return as double without precision lost
 				if (!unrestictBigDigit) {
 					double asDouble = Double.parseDouble(xs);
-					if (String.valueOf(asDouble).equals(xs))
+					final String doubleStr = String.valueOf(asDouble);
+					// we need a compare compat `e` `E` `e+` `E+`
+					if (compareDoublePrecision(doubleStr, xs)){
 						return asDouble;
+					}
 				}
-				return big;
+				return new BigDecimal(xs);
 			}
 
 			return Double.parseDouble(xs);
@@ -165,6 +167,33 @@ protected Number extractFloat() throws ParseException {
 		}
 	}
 
+	private boolean compareDoublePrecision(String convert, String origin) {
+		final char[] charArray = convert.toCharArray();
+		final char[] originArray = origin.toCharArray();
+		if (charArray.length > originArray.length) {
+			return false;
+		}
+		int j = 0;
+		for (int i = 0; i < charArray.length; i++) {
+			if (charArray[i] < '0' || charArray[i] > '9') {
+				if (originArray[j] >= '0' && originArray[j] <= '9') {
+					return false;
+				} else {
+					j++;
+					if (originArray[j] == '+') {
+						j++;
+					}
+					continue;
+				}
+			}
+			if (charArray[i] != originArray[j]) {
+				return false;
+			}
+			j++;
+		}
+		return j == originArray.length;
+	}
+
 	/**
 	 * use to return Primitive Type, or String, Or JsonObject or JsonArray
 	 * generated by a ContainerFactory
diff --git a/json-smart/src/test/java/net/minidev/json/test/TestBigDigitUnrestricted.java b/json-smart/src/test/java/net/minidev/json/test/TestBigDigitUnrestricted.java
index 8619a11..5d6933b 100644
--- a/json-smart/src/test/java/net/minidev/json/test/TestBigDigitUnrestricted.java
+++ b/json-smart/src/test/java/net/minidev/json/test/TestBigDigitUnrestricted.java
@@ -10,7 +10,7 @@
 import org.junit.jupiter.api.Test;
 
 public class TestBigDigitUnrestricted {
-	public static String[] VALID_DOUBLE_JSON = new String[] {"{\"v\":0.12345678912345678}"}; 
+	public static String[] VALID_DOUBLE_JSON = new String[] {"{\"v\":0.12345678912345678}", "\"v\":\"1.7976931348623157E308\"", "\"v\":\"1.7976931348623157E+308\"", "\"v\":\"1.7976931348623157e+308\""};
 	
 	@Test
 	public void testRestrictedBigDigit() throws Exception {