From 582d08c553fdd8bb3150e4d7c71619750ee340ce Mon Sep 17 00:00:00 2001
From: Henry Mercer <henrymercer@github.com>
Date: Wed, 18 Mar 2026 17:10:13 +0000
Subject: [PATCH] Explicitly set C/C++ trap caching env var to false

---
 lib/init-action.js  |  9 ++++++---
 src/config-utils.ts | 11 +++++++----
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/lib/init-action.js b/lib/init-action.js
index 6739e114a..86decde99 100644
--- a/lib/init-action.js
+++ b/lib/init-action.js
@@ -106869,9 +106869,12 @@ async function setCppTrapCachingEnvironmentVariables(config, logger) {
       logger.info(
         `Environment variable ${envVar} already set, leaving it unchanged.`
       );
-    } else {
-      logger.info("Enabling CodeQL C++ TRAP caching support.");
+    } else if (config.trapCaches["cpp" /* cpp */]) {
+      logger.info("Enabling TRAP caching for C/C++.");
       core9.exportVariable(envVar, "true");
+    } else {
+      logger.debug(`Disabling TRAP caching for C/C++.`);
+      core9.exportVariable(envVar, "false");
     }
   }
 }
@@ -107010,8 +107013,8 @@ async function initConfig(features, inputs) {
     );
     config.trapCaches = trapCaches;
     config.trapCacheDownloadTime = trapCacheDownloadTime;
-    await setCppTrapCachingEnvironmentVariables(config, logger);
   }
+  await setCppTrapCachingEnvironmentVariables(config, logger);
   return config;
 }
 function parseRegistries(registriesInput) {
diff --git a/src/config-utils.ts b/src/config-utils.ts
index 57fbf7da7..94e425d9a 100644
--- a/src/config-utils.ts
+++ b/src/config-utils.ts
@@ -1032,9 +1032,12 @@ async function setCppTrapCachingEnvironmentVariables(
       logger.info(
         `Environment variable ${envVar} already set, leaving it unchanged.`,
       );
-    } else {
-      logger.info("Enabling CodeQL C++ TRAP caching support.");
+    } else if (config.trapCaches[KnownLanguage.cpp]) {
+      logger.info("Enabling TRAP caching for C/C++.");
       core.exportVariable(envVar, "true");
+    } else {
+      logger.debug(`Disabling TRAP caching for C/C++.`);
+      core.exportVariable(envVar, "false");
     }
   }
 }
@@ -1238,10 +1241,10 @@ export async function initConfig(
     );
     config.trapCaches = trapCaches;
     config.trapCacheDownloadTime = trapCacheDownloadTime;
-
-    await setCppTrapCachingEnvironmentVariables(config, logger);
   }
 
+  await setCppTrapCachingEnvironmentVariables(config, logger);
+
   return config;
 }