correct error in converting doubles to big decimals

johnjaylward · johnjaylward · commit 579784d73efc · 2021-07-22T23:46:31.000-04:00
diff --git a/src/main/java/org/json/JSONObject.java b/src/main/java/org/json/JSONObject.java
@@ -1159,6 +1159,18 @@ public BigDecimal optBigDecimal(String key, BigDecimal defaultValue) {
      *          to convert.
      */
     static BigDecimal objectToBigDecimal(Object val, BigDecimal defaultValue) {
+        return objectToBigDecimal(val, defaultValue, true);
+    }
+    
+    /**
+     * @param val value to convert
+     * @param defaultValue default value to return is the conversion doesn't work or is null.
+     * @param exact When <code>true</code>, then {@link Double} and {@link Float} values will be converted exactly.
+     *      When <code>false</code>, they will be converted to {@link String} values before converting to {@link BigDecimal}.
+     * @return BigDecimal conversion of the original value, or the defaultValue if unable
+     *          to convert.
+     */
+    static BigDecimal objectToBigDecimal(Object val, BigDecimal defaultValue, boolean exact) {
         if (NULL.equals(val)) {
             return defaultValue;
         }
@@ -1172,7 +1184,14 @@ static BigDecimal objectToBigDecimal(Object val, BigDecimal defaultValue) {
             if (!numberIsFinite((Number)val)) {
                 return defaultValue;
             }
-            return new BigDecimal(((Number) val).doubleValue());
+            if (exact) {
+                return new BigDecimal(((Number)val).doubleValue());
+            }else {
+                // use the string constructor so that we maintain "nice" values for doubles and floats
+                // the double constructor will translate doubles to "exact" values instead of the likely
+                // intended representation
+                return new BigDecimal(val.toString());
+            }
         }
         if (val instanceof Long || val instanceof Integer
                 || val instanceof Short || val instanceof Byte){
@@ -2132,8 +2151,8 @@ static boolean isNumberSimilar(Number l, Number r) {
         // BigDecimal should be able to handle all of our number types that we support through
         // documentation. Convert to BigDecimal first, then use the Compare method to
         // decide equality.
-        final BigDecimal lBigDecimal = objectToBigDecimal(l, null);
-        final BigDecimal rBigDecimal = objectToBigDecimal(r, null);
+        final BigDecimal lBigDecimal = objectToBigDecimal(l, null, false);
+        final BigDecimal rBigDecimal = objectToBigDecimal(r, null, false);
         if (lBigDecimal == null || rBigDecimal == null) {
             return false;
         }
diff --git a/src/test/java/org/json/junit/JSONObjectTest.java b/src/test/java/org/json/junit/JSONObjectTest.java
@@ -126,6 +126,7 @@ public void verifySimilar() {
         
         assertTrue("Should eval to true", obj1.similar(obj4));
         
+        // verify that a double and big decimal are "similar"
         assertTrue("should eval to true",new JSONObject().put("a",1.1d).similar(new JSONObject("{\"a\":1.1}")));
         
     }
@@ -942,7 +943,7 @@ public void stringToValueNumbersTest() {
         assertTrue("-0 Should be a Double!",JSONObject.stringToValue("-0")  instanceof Double);
         assertTrue("-0.0 Should be a Double!",JSONObject.stringToValue("-0.0") instanceof Double);
         assertTrue("'-' Should be a String!",JSONObject.stringToValue("-") instanceof String);
-        assertTrue( "0.2 should be a Double!",
+        assertTrue( "0.2 should be a BigDecimal!",
                 JSONObject.stringToValue( "0.2" ) instanceof BigDecimal );
         assertTrue( "Doubles should be BigDecimal, even when incorrectly converting floats!",
                 JSONObject.stringToValue( new Double( "0.2f" ).toString() ) instanceof BigDecimal );
