try to fix issue where _numberString is used despite having old value

src/main/java/com/fasterxml/jackson/core/base/ParserBase.java

@@ -785,6 +785,7 @@ public int getIntValue() throws IOException
             }
             if ((_numTypesValid & NR_INT) == 0) { // wasn't an int natively?
                 convertNumberToInt(); // let's make it so, if possible
+                _numberString = null;
             }
         }
         return _numberInt;
@@ -799,6 +800,7 @@ public long getLongValue() throws IOException
             }
             if ((_numTypesValid & NR_LONG) == 0) {
                 convertNumberToLong();
+                _numberString = null;
             }
         }
         return _numberLong;
@@ -813,6 +815,8 @@ public BigInteger getBigIntegerValue() throws IOException
             }
             if ((_numTypesValid & NR_BIGINT) == 0) {
                 convertNumberToBigInteger();
+                _numberString = null;
+                return _numberBigInt;
             }
         }
         return _getBigInteger();
@@ -835,6 +839,8 @@ public float getFloatValue() throws IOException
             }
             if ((_numTypesValid & NR_FLOAT) == 0) {
                 convertNumberToFloat();
+                _numberString = null;
+                return _numberFloat;
             }
         }
         return _getNumberFloat();
@@ -850,6 +856,8 @@ public double getDoubleValue() throws IOException
             // if underlying type not FP, need conversion:
             if ((_numTypesValid & NR_DOUBLE) == 0) {
                 convertNumberToDouble();
+                _numberString = null;
+                return _numberDouble;
             }
         }
         return _getNumberDouble();
@@ -864,6 +872,8 @@ public BigDecimal getDecimalValue() throws IOException
             }
             if ((_numTypesValid & NR_BIGDECIMAL) == 0) {
                 convertNumberToBigDecimal();
+                _numberString = null;
+                return _numberBigDecimal;
             }
         }
         return _getBigDecimal();

src/test/java/com/fasterxml/jackson/core/read/JsonNumberParsingTest.java

@@ -0,0 +1,75 @@
+package com.fasterxml.jackson.core.read;
+
+import com.fasterxml.jackson.core.JUnit5TestBase;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.core.TokenStreamFactory;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.math.BigDecimal;
+import java.math.BigInteger;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class JsonNumberParsingTest extends JUnit5TestBase
+{
+    // [jackson-databind#4917]
+    @Test
+    public void bigDecimal4917() throws Exception
+    {
+        final String json = a2q("{'decimalHolder':100.00,'number':50}");
+        TokenStreamFactory jsonF = newStreamFactory();
+        for (int mode : ALL_MODES) {
+            testBigDecimal4917(jsonF, mode, json, false, JsonParser.NumberType.DOUBLE);
+            testBigDecimal4917(jsonF, mode, json, true, JsonParser.NumberType.DOUBLE);
+            testBigDecimal4917(jsonF, mode, json, true, JsonParser.NumberType.FLOAT);
+            testBigDecimal4917(jsonF, mode, json, true, JsonParser.NumberType.BIG_DECIMAL);
+            testBigDecimal4917(jsonF, mode, json, true, JsonParser.NumberType.BIG_INTEGER);
+            testBigDecimal4917(jsonF, mode, json, true, JsonParser.NumberType.INT);
+            testBigDecimal4917(jsonF, mode, json, true, JsonParser.NumberType.LONG);
+        }
+    }
+
+    private void testBigDecimal4917(final TokenStreamFactory jsonF,
+                                    final int mode,
+                                    final String json,
+                                    final boolean checkFirstNumValues,
+                                    final JsonParser.NumberType secondNumTypeCheck) throws IOException {
+        // checkFirstNumValues=false reproduces the issue in https://github.com/FasterXML/jackson-databind/issues/4917
+        // it is useful to check the second number value while requesting different number types
+        // but the call adjusts state of the parser, so it is better to redo the test and then test w
+        try (JsonParser p = createParser(jsonF, mode, json)) {
+            assertToken(JsonToken.START_OBJECT, p.nextToken());
+            assertToken(JsonToken.FIELD_NAME, p.nextToken());
+            assertEquals("decimalHolder", p.currentName());
+            assertToken(JsonToken.VALUE_NUMBER_FLOAT, p.nextToken());
+            assertEquals(JsonParser.NumberType.DOUBLE, p.getNumberType());
+            if (checkFirstNumValues) {
+                assertEquals(Double.valueOf(100.0), p.getNumberValueDeferred());
+                assertEquals(new BigDecimal("100.00"), p.getDecimalValue());
+            }
+            assertEquals("100.00", p.getText());
+            assertToken(JsonToken.FIELD_NAME, p.nextToken());
+            assertEquals("number", p.currentName());
+            assertToken(JsonToken.VALUE_NUMBER_INT, p.nextToken());
+            assertEquals(JsonParser.NumberType.INT, p.getNumberType());
+            assertEquals(Integer.valueOf(50), p.getNumberValueDeferred());
+            if (secondNumTypeCheck == JsonParser.NumberType.BIG_DECIMAL) {
+                assertEquals(new BigDecimal("50"), p.getDecimalValue());
+            } else if (secondNumTypeCheck == JsonParser.NumberType.BIG_INTEGER) {
+                assertEquals(new BigInteger("50"), p.getBigIntegerValue());
+            } else if (secondNumTypeCheck == JsonParser.NumberType.FLOAT) {
+                assertEquals(50.0f, p.getFloatValue());
+            } else if (secondNumTypeCheck == JsonParser.NumberType.LONG) {
+                assertEquals(50L, p.getLongValue());
+            } else if (secondNumTypeCheck == JsonParser.NumberType.INT) {
+                assertEquals(50, p.getIntValue());
+            } else {
+                assertEquals(50.0d, p.getDoubleValue());
+            }
+            assertEquals(50, p.getIntValue());
+            assertToken(JsonToken.END_OBJECT, p.nextToken());
+        }
+    }
+}