Fix parsing of value with comma

Closes gh-12297

spring-boot/src/main/java/org/springframework/boot/json/BasicJsonParser.java

@@ -124,6 +124,7 @@ public class BasicJsonParser implements JsonParser {
 		int index = 0;
 		int inObject = 0;
 		int inList = 0;
+		boolean inValue = false;
 		StringBuilder build = new StringBuilder();
 		while (index < json.length()) {
 			char current = json.charAt(index);
@@ -139,7 +140,10 @@ public class BasicJsonParser implements JsonParser {
 			if (current == ']') {
 				inList--;
 			}
-			if (current == ',' && inObject == 0 && inList == 0) {
+			if (current == '"') {
+				inValue = !inValue;
+			}
+			if (current == ',' && inObject == 0 && inList == 0 && !inValue) {
 				list.add(build.toString());
 				build.setLength(0);
 			}

spring-boot/src/test/java/org/springframework/boot/json/AbstractJsonParserTests.java

@@ -30,6 +30,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  *
  * @author Dave Syer
  * @author Jean de Klerk
+ * @author Stephane Nicoll
  */
 public abstract class AbstractJsonParserTests {
 
@@ -63,6 +64,13 @@ public abstract class AbstractJsonParserTests {
 		assertThat(map.get("foo")).isEqualTo("123");
 	}
 
+	@Test
+	public void stringContainingComma() {
+		Map<String, Object> map = this.parser.parseMap("{\"foo\":\"bar1,bar2\"}");
+		assertThat(map).hasSize(1);
+		assertThat(map.get("foo")).isEqualTo("bar1,bar2");
+	}
+
 	@Test
 	public void emptyMap() {
 		Map<String, Object> map = this.parser.parseMap("{}");