From 70db156dcb3b4e4b3cd25cb65cb0a925c14298be Mon Sep 17 00:00:00 2001
From: Henry Mercer <henrymercer@github.com>
Date: Wed, 25 Feb 2026 11:44:45 +0000
Subject: [PATCH] Add diagnostic when overlay disabled by repo property

---
 lib/init-action.js       | 32 +++++++++++++++++++++++++++++---
 src/config-utils.test.ts |  3 +++
 src/config-utils.ts      | 31 +++++++++++++++++++++++++++++++
 3 files changed, 63 insertions(+), 3 deletions(-)

diff --git a/lib/init-action.js b/lib/init-action.js
index e85eaeb08..6c9b6d53a 100644
--- a/lib/init-action.js
+++ b/lib/init-action.js
@@ -106249,6 +106249,7 @@ async function getOverlayDatabaseMode(codeql, features, languages, sourceRoot, b
   let overlayDatabaseMode = "none" /* None */;
   let useOverlayDatabaseCaching = false;
   let skippedDueToCachedStatus = false;
+  let disabledByRepositoryProperty = false;
   const modeEnv = process.env.CODEQL_OVERLAY_DATABASE_MODE;
   if (modeEnv === "overlay" /* Overlay */ || modeEnv === "overlay-base" /* OverlayBase */ || modeEnv === "none" /* None */) {
     overlayDatabaseMode = modeEnv;
@@ -106260,6 +106261,7 @@ async function getOverlayDatabaseMode(codeql, features, languages, sourceRoot, b
       `Setting overlay database mode to ${"none" /* None */} because the ${"github-codeql-disable-overlay" /* DISABLE_OVERLAY */} repository property is set to true.`
     );
     overlayDatabaseMode = "none" /* None */;
+    disabledByRepositoryProperty = true;
   } else if (await isOverlayAnalysisFeatureEnabled(
     features,
     codeql,
@@ -106312,7 +106314,8 @@ async function getOverlayDatabaseMode(codeql, features, languages, sourceRoot, b
   const nonOverlayAnalysis = {
     overlayDatabaseMode: "none" /* None */,
     useOverlayDatabaseCaching: false,
-    skippedDueToCachedStatus
+    skippedDueToCachedStatus,
+    disabledByRepositoryProperty
   };
   if (overlayDatabaseMode === "none" /* None */) {
     return nonOverlayAnalysis;
@@ -106358,7 +106361,8 @@ async function getOverlayDatabaseMode(codeql, features, languages, sourceRoot, b
   return {
     overlayDatabaseMode,
     useOverlayDatabaseCaching,
-    skippedDueToCachedStatus
+    skippedDueToCachedStatus,
+    disabledByRepositoryProperty
   };
 }
 function dbLocationOrDefault(dbLocation, tempDir) {
@@ -106450,7 +106454,8 @@ async function initConfig(features, inputs) {
   const {
     overlayDatabaseMode,
     useOverlayDatabaseCaching,
-    skippedDueToCachedStatus: overlaySkippedDueToCachedStatus
+    skippedDueToCachedStatus: overlaySkippedDueToCachedStatus,
+    disabledByRepositoryProperty: overlayDisabledByRepositoryProperty
   } = await getOverlayDatabaseMode(
     inputs.codeql,
     inputs.features,
@@ -106491,6 +106496,27 @@ Improved incremental analysis will be automatically retried when the next versio
       )
     );
   }
+  if (overlayDisabledByRepositoryProperty) {
+    addNoLanguageDiagnostic(
+      config,
+      makeDiagnostic(
+        "codeql-action/overlay-disabled-by-repository-property",
+        "Improved incremental analysis disabled by repository property",
+        {
+          attributes: {
+            languages: config.languages
+          },
+          markdownMessage: `Improved incremental analysis has been disabled because the \`${"github-codeql-disable-overlay" /* DISABLE_OVERLAY */}\` repository property is set to \`true\`. To re-enable improved incremental analysis, set this property to \`false\` or remove it.`,
+          severity: "note",
+          visibility: {
+            cliSummaryTable: true,
+            statusPage: true,
+            telemetry: true
+          }
+        }
+      )
+    );
+  }
   if (overlayDatabaseMode === "overlay" /* Overlay */ || await shouldPerformDiffInformedAnalysis(
     inputs.codeql,
     inputs.features,
diff --git a/src/config-utils.test.ts b/src/config-utils.test.ts
index 9e0064fe3..769fd14d3 100644
--- a/src/config-utils.test.ts
+++ b/src/config-utils.test.ts
@@ -1019,6 +1019,7 @@ const getOverlayDatabaseModeMacro = test.macro({
       overlayDatabaseMode: OverlayDatabaseMode;
       useOverlayDatabaseCaching: boolean;
       skippedDueToCachedStatus?: boolean;
+      disabledByRepositoryProperty?: boolean;
     },
   ) => {
     return await withTmpDir(async (tempDir) => {
@@ -1092,6 +1093,7 @@ const getOverlayDatabaseModeMacro = test.macro({
 
         t.deepEqual(result, {
           skippedDueToCachedStatus: false,
+          disabledByRepositoryProperty: false,
           ...expected,
         });
       } finally {
@@ -1938,6 +1940,7 @@ test(
   {
     overlayDatabaseMode: OverlayDatabaseMode.None,
     useOverlayDatabaseCaching: false,
+    disabledByRepositoryProperty: true,
   },
 );
 
diff --git a/src/config-utils.ts b/src/config-utils.ts
index 7f2b86a15..0d7e51fb0 100644
--- a/src/config-utils.ts
+++ b/src/config-utils.ts
@@ -760,10 +760,12 @@ export async function getOverlayDatabaseMode(
   overlayDatabaseMode: OverlayDatabaseMode;
   useOverlayDatabaseCaching: boolean;
   skippedDueToCachedStatus: boolean;
+  disabledByRepositoryProperty: boolean;
 }> {
   let overlayDatabaseMode = OverlayDatabaseMode.None;
   let useOverlayDatabaseCaching = false;
   let skippedDueToCachedStatus = false;
+  let disabledByRepositoryProperty = false;
 
   const modeEnv = process.env.CODEQL_OVERLAY_DATABASE_MODE;
   // Any unrecognized CODEQL_OVERLAY_DATABASE_MODE value will be ignored and
@@ -786,6 +788,7 @@ export async function getOverlayDatabaseMode(
         `because the ${RepositoryPropertyName.DISABLE_OVERLAY} repository property is set to true.`,
     );
     overlayDatabaseMode = OverlayDatabaseMode.None;
+    disabledByRepositoryProperty = true;
   } else if (
     await isOverlayAnalysisFeatureEnabled(
       features,
@@ -856,6 +859,7 @@ export async function getOverlayDatabaseMode(
     overlayDatabaseMode: OverlayDatabaseMode.None,
     useOverlayDatabaseCaching: false,
     skippedDueToCachedStatus,
+    disabledByRepositoryProperty,
   };
 
   if (overlayDatabaseMode === OverlayDatabaseMode.None) {
@@ -921,6 +925,7 @@ export async function getOverlayDatabaseMode(
     overlayDatabaseMode,
     useOverlayDatabaseCaching,
     skippedDueToCachedStatus,
+    disabledByRepositoryProperty,
   };
 }
 
@@ -1071,6 +1076,7 @@ export async function initConfig(
     overlayDatabaseMode,
     useOverlayDatabaseCaching,
     skippedDueToCachedStatus: overlaySkippedDueToCachedStatus,
+    disabledByRepositoryProperty: overlayDisabledByRepositoryProperty,
   } = await getOverlayDatabaseMode(
     inputs.codeql,
     inputs.features,
@@ -1119,6 +1125,31 @@ export async function initConfig(
     );
   }
 
+  if (overlayDisabledByRepositoryProperty) {
+    addNoLanguageDiagnostic(
+      config,
+      makeDiagnostic(
+        "codeql-action/overlay-disabled-by-repository-property",
+        "Improved incremental analysis disabled by repository property",
+        {
+          attributes: {
+            languages: config.languages,
+          },
+          markdownMessage:
+            "Improved incremental analysis has been disabled because the " +
+            `\`${RepositoryPropertyName.DISABLE_OVERLAY}\` repository property is set to \`true\`. ` +
+            "To re-enable improved incremental analysis, set this property to `false` or remove it.",
+          severity: "note",
+          visibility: {
+            cliSummaryTable: true,
+            statusPage: true,
+            telemetry: true,
+          },
+        },
+      ),
+    );
+  }
+
   if (
     overlayDatabaseMode === OverlayDatabaseMode.Overlay ||
     (await shouldPerformDiffInformedAnalysis(