Issue #2290: Fix NPE in isOverriddenMethod during validation of methods with implicit modifiers

3 files changed, 32 insertions, 5 deletions

diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/checks/naming/ParameterNameCheck.java b/src/main/java/com/puppycrawl/tools/checkstyle/checks/naming/ParameterNameCheck.java
index 9152f7063..3658dc4b4 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/checks/naming/ParameterNameCheck.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/checks/naming/ParameterNameCheck.java
@@ -118,11 +118,13 @@ public class ParameterNameCheck
     private static boolean isOverriddenMethod(DetailAST ast) {
         boolean overridden = false;
         final DetailAST parent = ast.getParent().getParent();
-        final DetailAST annotation = parent.getFirstChild().getFirstChild();
-        if (annotation.getType() == TokenTypes.ANNOTATION) {
-            final DetailAST overrideToken = annotation.findFirstToken(TokenTypes.IDENT);
-            if ("Override".equals(overrideToken.getText())) {
-                overridden = true;
+        if (parent.getFirstChild().getFirstChild() != null) {
+            final DetailAST annotation = parent.getFirstChild().getFirstChild();
+            if (annotation.getType() == TokenTypes.ANNOTATION) {
+                final DetailAST overrideToken = annotation.findFirstToken(TokenTypes.IDENT);
+                if ("Override".equals(overrideToken.getText())) {
+                    overridden = true;
+                }
             }
         }
         return overridden;
diff --git a/src/test/java/com/puppycrawl/tools/checkstyle/checks/naming/ParameterNameCheckTest.java b/src/test/java/com/puppycrawl/tools/checkstyle/checks/naming/ParameterNameCheckTest.java
index e595e4999..1c35fd32e 100644
--- a/src/test/java/com/puppycrawl/tools/checkstyle/checks/naming/ParameterNameCheckTest.java
+++ b/src/test/java/com/puppycrawl/tools/checkstyle/checks/naming/ParameterNameCheckTest.java
@@ -106,6 +106,11 @@ public class ParameterNameCheckTest
         final String[] expected = {
             "11:28: " + getCheckMessage(MSG_INVALID_PATTERN, "object", pattern),
             "15:30: " + getCheckMessage(MSG_INVALID_PATTERN, "aaaa", pattern),
+            "19:19: " + getCheckMessage(MSG_INVALID_PATTERN, "abc", pattern),
+            "19:28: " + getCheckMessage(MSG_INVALID_PATTERN, "bd", pattern),
+            "21:18: " + getCheckMessage(MSG_INVALID_PATTERN, "abc", pattern),
+            "28:33: " + getCheckMessage(MSG_INVALID_PATTERN, "field", pattern),
+            "28:62: " + getCheckMessage(MSG_INVALID_PATTERN, "packageNames", pattern),
             };
         verify(checkConfig, getPath("InputOverrideAnnotation.java"), expected);
     }
@@ -124,6 +129,11 @@ public class ParameterNameCheckTest
             "6:34: " + getCheckMessage(MSG_INVALID_PATTERN, "o", pattern),
             "11:28: " + getCheckMessage(MSG_INVALID_PATTERN, "object", pattern),
             "15:30: " + getCheckMessage(MSG_INVALID_PATTERN, "aaaa", pattern),
+            "19:19: " + getCheckMessage(MSG_INVALID_PATTERN, "abc", pattern),
+            "19:28: " + getCheckMessage(MSG_INVALID_PATTERN, "bd", pattern),
+            "21:18: " + getCheckMessage(MSG_INVALID_PATTERN, "abc", pattern),
+            "28:33: " + getCheckMessage(MSG_INVALID_PATTERN, "field", pattern),
+            "28:62: " + getCheckMessage(MSG_INVALID_PATTERN, "packageNames", pattern),
             };
         verify(checkConfig, getPath("InputOverrideAnnotation.java"), expected);
     }
diff --git a/src/test/resources/com/puppycrawl/tools/checkstyle/checks/naming/InputOverrideAnnotation.java b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/naming/InputOverrideAnnotation.java
index 82d99508a..e4e40d126 100644
--- a/src/test/resources/com/puppycrawl/tools/checkstyle/checks/naming/InputOverrideAnnotation.java
+++ b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/naming/InputOverrideAnnotation.java
@@ -13,4 +13,19 @@ public class InputOverrideAnnotation {
     }
 
     public void foo2(Integer aaaa) {}
+
+    void foo3() {} // No NPE here!
+
+    void foo4(int abc, int bd) {} // No NPE here!
+
+    int foo5(int abc) {return 1;} // No NPE here!
+
+    private int field;
+    private java.util.Set<String> packageNames;
+
+    InputOverrideAnnotation() {} // No NPE here!
+
+    InputOverrideAnnotation(int field, java.util.Set<String> packageNames) {} // No NPE here!
+
+
 }