From e4f4619b74420086d67395209df7d84d420793e9 Mon Sep 17 00:00:00 2001
From: Tomasz Tylenda <tomasz.tylenda@sonarsource.com>
Date: Wed, 4 Feb 2026 15:21:40 +0100
Subject: [PATCH 1/2] SONARJAVA-6095 S1166 should not report when exception
 uses unnamed variable

---
 .../main/java/checks/CatchUsesExceptionWithContextCheck.java   | 3 +++
 .../sonar/java/checks/CatchUsesExceptionWithContextCheck.java  | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/java-checks-test-sources/default/src/main/java/checks/CatchUsesExceptionWithContextCheck.java b/java-checks-test-sources/default/src/main/java/checks/CatchUsesExceptionWithContextCheck.java
index f35ce10abc0..ceaa44893f9 100644
--- a/java-checks-test-sources/default/src/main/java/checks/CatchUsesExceptionWithContextCheck.java
+++ b/java-checks-test-sources/default/src/main/java/checks/CatchUsesExceptionWithContextCheck.java
@@ -65,6 +65,9 @@ private void f(Exception x) {
         System.out.println("" + e);
       }
     }
+    try {
+    } catch (Exception _) {                     // Compliant
+    }
   }
 
   private void g() {
diff --git a/java-checks/src/main/java/org/sonar/java/checks/CatchUsesExceptionWithContextCheck.java b/java-checks/src/main/java/org/sonar/java/checks/CatchUsesExceptionWithContextCheck.java
index 88c031030a0..65e994d0e9a 100644
--- a/java-checks/src/main/java/org/sonar/java/checks/CatchUsesExceptionWithContextCheck.java
+++ b/java-checks/src/main/java/org/sonar/java/checks/CatchUsesExceptionWithContextCheck.java
@@ -170,7 +170,7 @@ public void visitLambdaExpression(LambdaExpressionTree lambdaExpressionTree) {
 
   @Override
   public void visitCatch(CatchTree tree) {
-    if (!isExcludedType(tree.parameter().type()) && !excludedCatchTrees.contains(tree)) {
+    if (!isExcludedType(tree.parameter().type()) && !excludedCatchTrees.contains(tree) && !tree.parameter().simpleName().isUnnamedVariable()) {
       Symbol exception = tree.parameter().symbol();
       usageStatusStack.addFirst(new UsageStatus(exception.usages()));
       super.visitCatch(tree);

From 058eb63657b97ea94e4690f491c0192e90286aca Mon Sep 17 00:00:00 2001
From: Tomasz Tylenda <tomasz.tylenda@sonarsource.com>
Date: Thu, 5 Feb 2026 11:48:41 +0100
Subject: [PATCH 2/2] Update rspec

---
 .../org/sonar/l10n/java/rules/java/S1166.html          | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/sonar-java-plugin/src/main/resources/org/sonar/l10n/java/rules/java/S1166.html b/sonar-java-plugin/src/main/resources/org/sonar/l10n/java/rules/java/S1166.html
index 817abcb5bd2..ce600dff0f9 100644
--- a/sonar-java-plugin/src/main/resources/org/sonar/l10n/java/rules/java/S1166.html
+++ b/sonar-java-plugin/src/main/resources/org/sonar/l10n/java/rules/java/S1166.html
@@ -68,6 +68,16 @@ <h3>Exceptions</h3>
   LOGGER.warn(message); // Compliant - exception message logged with some contextual information
 }
 </pre>
+<p>Additionally, no issue will be raised if the exception parameter uses the unnamed variable <code>_</code>, which is available starting with Java
+21. The unnamed variable makes it explicit that the exception is caught but not needed in the handler (see {rule:java:S7467}).</p>
+<pre>
+try {
+  /* ... */
+} catch (Exception _) {
+  // Compliant - unnamed exception parameter is intentionally unused
+  return defaultValue;
+}
+</pre>
 <h2>Resources</h2>
 <ul>
   <li> OWASP - <a href="https://owasp.org/Top10/A09_2021-Security_Logging_and_Monitoring_Failures/">Top 10 2021 Category A9 - Security Logging and