add new integration test to check that sonar.java.jdkHome has default…

… value even without configuration from user

its/projects/jdkHome/extractFromJre/pom.xml

@@ -0,0 +1,8 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>com.sonarsource.it.samples</groupId>
+  <artifactId>extract-jre</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <name>Sonar :: Integration Tests :: Extract Jre</name>
+
+</project>

its/projects/jdkHome/extractFromJre/src/main/java/sample/Sample.java

@@ -0,0 +1,12 @@
+package sample;
+
+public class Sample {
+
+	public Sample(int i) {
+		int j = i++;
+	}
+
+	public String myMethod() {
+		return "hello";
+	}
+}

its/projects/jdkHome/extractFromJre/src/test/java/sample/SampleTest.java

@@ -0,0 +1,12 @@
+package sample;
+
+import org.junit.Test;
+
+public class SampleTest {
+
+	@Test
+	public void test() {
+	  new Sample(1).myMethod();
+	}
+
+}

its/src/test/java/com/sonar/maven/it/suite/JavaTest.java

@@ -120,6 +120,24 @@ void setJavaVersionProperties() throws IOException {
       entry("sonar.java.target", "1.8"));
   }
 
+  @Test
+  void extractJdkHomeFromJre() throws IOException {
+    File outputProps = temp.resolve("out.properties").toFile();
+    outputProps.createNewFile();
+
+    File pom = ItUtils.locateProjectPom("jdkHome/extractFromJre");
+    MavenBuild build = MavenBuild.create(pom)
+      .setGoals(sonarGoal())
+      .setProperty("sonar.scanner.internal.dumpToFile", outputProps.getAbsolutePath());
+    executeBuildAndValidateWithoutCE(build);
+
+    Properties props = getProps(outputProps);
+    Object value = props.getOrDefault("sonar.java.jdkHome", "");
+    if(value instanceof String){
+      assertThat((String)value).isNotEmpty();
+    }
+  }
+
   @Test
   void setJdkHomeFromCompilerExecutableConfiguration() throws IOException {
     File outputProps = temp.resolve("out.properties").toFile();
@@ -136,6 +154,7 @@ void setJdkHomeFromCompilerExecutableConfiguration() throws IOException {
     assertThat(props).contains(entry("sonar.java.jdkHome", expected));
   }
 
+
   @Test
   void setJdkHomeFromGlobalToolchainsPlugin() throws IOException {
     File outputProps = temp.resolve("out.properties").toFile();