SONAR-19096 add non-null check on the sanitizing of the relative path.

sonar-plugin-api-impl/src/main/java/org/sonar/api/batch/fs/internal/DefaultIndexedFile.java

@@ -68,7 +68,7 @@ public class DefaultIndexedFile extends DefaultInputComponent implements Indexed
     SensorStrategy sensorStrategy, @Nullable String oldRelativeFilePath) {
     super(batchId);
     this.projectKey = projectKey;
-    this.projectRelativePath = PathUtils.sanitize(projectRelativePath);
+    this.projectRelativePath = checkSanitize(projectRelativePath);
     this.moduleRelativePath = PathUtils.sanitize(moduleRelativePath);
     this.type = type;
     this.language = language;
@@ -78,6 +78,14 @@ public class DefaultIndexedFile extends DefaultInputComponent implements Indexed
     validateKeyLength();
   }
 
+  static String checkSanitize(String relativePath) {
+    String sanitized = PathUtils.sanitize(relativePath);
+    if(sanitized == null) {
+      throw new IllegalArgumentException(String.format("The path '%s' must sanitize to a non-null value", relativePath));
+    }
+    return sanitized;
+  }
+
   private void validateKeyLength() {
     String key = key();
     if (key.length() > MAX_KEY_LENGTH) {

sonar-plugin-api-impl/src/test/java/org/sonar/api/batch/fs/internal/DefaultIndexedFileTest.java

@@ -35,4 +35,12 @@ public class DefaultIndexedFileTest {
       .isInstanceOf(IllegalStateException.class)
       .hasMessageEndingWith("length (401) is longer than the maximum authorized (400)");
   }
+
+  @Test
+  public void sanitize_shouldThrow_whenRelativePathIsInvalid() {
+    String invalidPath = "./../foo/bar";
+    Assertions.assertThatThrownBy(() -> DefaultIndexedFile.checkSanitize(invalidPath))
+      .isInstanceOf(IllegalArgumentException.class)
+      .hasMessageContaining(invalidPath);
+  }
 }