From e5f048698711a262b6e64110085d8c0ca878c6ae Mon Sep 17 00:00:00 2001
From: Thomas Schouten <thomas.schouten@prodrive-technologies.com>
Date: Wed, 27 Nov 2024 09:47:49 +0100
Subject: [PATCH] Check if file is still valid after retrieving from cache (it
 may have been deleted)

---
 CHANGELOG.md                                                   | 1 +
 .../hannahsten/texifyidea/util/files/ReferencedFileSetCache.kt | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4a3da820f..8abfafd7d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 ### Added
 
 ### Fixed
+* Fix exception #3771 when a file referenced from cache is deleted
 * Fix basic case of false positive of duplicate label inspection when user defined \if commands are used
 * Fix a parse error when using \else with a user defined \if-command
 
diff --git a/src/nl/hannahsten/texifyidea/util/files/ReferencedFileSetCache.kt b/src/nl/hannahsten/texifyidea/util/files/ReferencedFileSetCache.kt
index e579cb6bb..4c61fdd2d 100644
--- a/src/nl/hannahsten/texifyidea/util/files/ReferencedFileSetCache.kt
+++ b/src/nl/hannahsten/texifyidea/util/files/ReferencedFileSetCache.kt
@@ -122,7 +122,8 @@ class ReferencedFileSetCache {
                     }
                 }
             }
-            cache[file.virtualFile]?.mapNotNull { it.element }?.toSet() ?: setOf(file)
+            // Make sure to check if file is still valid after retrieving from cache (it may have been deleted)
+            cache[file.virtualFile]?.mapNotNull { it.element }?.filter { it.isValid }?.toSet() ?: setOf(file)
         }
         else {
             setOf(file)