diff --git a/issues-fest.iml b/issues-fest.iml
new file mode 100644
index 0000000..c0460a6
--- /dev/null
+++ b/issues-fest.iml
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/tests" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/tests/integration" isTestSource="true" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="module" module-name="issues-fest2" scope="TEST" />
+  </component>
+</module>
\ No newline at end of file
diff --git a/src/issues-fest2.iml b/src/issues-fest2.iml
new file mode 100644
index 0000000..d6ebd48
--- /dev/null
+++ b/src/issues-fest2.iml
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$" />
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>
\ No newline at end of file
diff --git a/src/java/Authentication.java b/src/java/Authentication.java
index 54928d8..9703466 100644
--- a/src/java/Authentication.java
+++ b/src/java/Authentication.java
@@ -33,6 +33,12 @@ public void registerUser(String username, String password) {
     // BUG: No null checks - will throw NullPointerException
     // BUG: Plain text password comparison - SECURITY ISSUE
     public boolean login(String username, String password) {
+        if (username == null || password == null) {
+            return false;
+        }
+        if (!users.containsKey(username)) {
+            return false;
+        }
         String storedPassword = users.get(username);
         boolean isValid = storedPassword.equals(password);
 
diff --git a/src/python/csv_processor.py b/src/python/csv_processor.py
index 4758eed..290c2b5 100644
--- a/src/python/csv_processor.py
+++ b/src/python/csv_processor.py
@@ -39,7 +39,7 @@ def filter_rows(data, column_name, value):
 # TYPO: "aggrigate" instead of "aggregate"
 # BUG: Assumes all values are numeric without validation
 # BUG: No error handling for non-numeric values
-def aggrigate_column(data, column_name):
+def aggregate_column(data, column_name):
     """Sum all values in a column"""
     values = get_column(data, column_name)
     return sum(float(v) for v in values)
diff --git a/tests/TestRunner.java b/tests/TestRunner.java
index df7b27d..0a86115 100644
--- a/tests/TestRunner.java
+++ b/tests/TestRunner.java
@@ -17,9 +17,9 @@ public void printSummary() {
         System.out.println("Tests passed: " + passedTests);
         System.out.println("Tests failed: " + failedTests);
     }
-}
-
+    
     // TYPO: "reportt" instead of "report"
     public String reportt() {
         return "Passed: " + passedTests + ", Failed: " + failedTests;
     }
+}