fix: inner types without file should not crash Environment#report

src/main/java/spoon/support/StandardEnvironment.java

@@ -256,18 +256,32 @@ public void report(Processor<?> processor, Level level, CtElement element, Strin
 		if (sp == null) {
 			buffer.append(" (Unknown Source)");
 		} else {
-			// TODO: will explode if type == null
-			buffer.append(" at " + type.getQualifiedName() + ".");
+			if (type != null) {
+				buffer.append(" at ")
+							.append(type.getQualifiedName())
+							.append(".");
+			} else {
+				buffer.append("at (?).");
+			}
 			CtExecutable<?> exe = (element instanceof CtExecutable) ? (CtExecutable<?>) element : element.getParent(CtExecutable.class);
 			if (exe != null) {
 				buffer.append(exe.getSimpleName());
 			}
-			buffer.append("(" + sp.getFile().getName() + ":" + sp.getLine() + ")");
+			if (sp.getFile() != null) {
+				buffer.append("(")
+							.append(sp.getFile().getName())
+							.append(":")
+							.append(sp.getLine())
+							.append(")");
+			} else {
+				buffer.append("(?:?)");
+			}
 		}
 
 		print(buffer.toString(), level);
 	}
 
+
 	@Override
 	public void report(Processor<?> processor, Level level, String message) {
 		StringBuilder buffer = new StringBuilder();

src/test/java/spoon/test/logging/LogTest.java

@@ -20,15 +20,23 @@
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.provider.MethodSource;
 import org.junit.jupiter.params.ParameterizedTest;
+import spoon.FluentLauncher;
 import spoon.Launcher;
 import spoon.MavenLauncher;
+import spoon.processing.AbstractProcessor;
+import spoon.reflect.CtModel;
+import spoon.reflect.code.CtInvocation;
+import spoon.reflect.declaration.CtConstructor;
+import spoon.reflect.visitor.Query;
+import spoon.reflect.visitor.filter.TypeFilter;
 import spoon.support.JavaOutputProcessor;
 import spoon.support.Level;
+import spoon.test.GitHubIssue;
 import uk.org.lidalia.slf4jtest.TestLogger;
 import uk.org.lidalia.slf4jtest.TestLoggerFactory;
-
+import java.util.List;
 import java.util.stream.Stream;
-
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -103,4 +111,21 @@ public void testLoggingOff() {
 		}
 		assertEquals(0, logger.getLoggingEvents().size());
 	}
-}
+
+	@GitHubIssue(issueNumber = 4997, fixed = true)
+	void innerTypesCrashesLogging() {
+		// contract: when a class has inner types, the logging should not crash with a NPE
+		String codePath = "src/test/resources/logging/TestCase2.java";
+		var processor = new AbstractProcessor<CtConstructor<?>>() {
+			@Override
+			public void process(CtConstructor<?> element) {
+				// do nothing
+			}
+			public boolean isToBeProcessed(CtConstructor<?> candidate) {
+        			List<CtInvocation<?>> invocations = Query.getElements(candidate, new TypeFilter<>(CtInvocation.class));
+        			invocations.forEach(i -> getEnvironment().report(this, Level.INFO, i, "Message"));
+       				return false;
+	  		}};
+		assertDoesNotThrow(() -> new FluentLauncher().inputResource(codePath).processor(processor).buildModel());
+	}
+}

src/test/resources/logging/TestCase2.java

@@ -0,0 +1,33 @@
+package fr.inria.gforge.spoon.analysis;
+
+/**
+ * The Class Testcase2.
+ *
+ * testcase to show NullPointerException
+ */
+public class Testcase2 {
+
+  private class A {
+
+  }
+
+  private class B extends A {
+
+    /**
+     * Instantiates a new b.
+     */
+    public B() {
+      super();
+    }
+  }
+
+  public static void main(String[] args) {
+    Testcase2 t = new Testcase2();
+    t.test();
+  }
+
+  public String test() {
+    var b = new B();
+    return b.toString();
+  }
+}