From 014cd62729fa9884c10264384e0f5f57f74492dc Mon Sep 17 00:00:00 2001
From: gamer147 <gamer147@gmail.com>
Date: Fri, 12 Jun 2026 12:03:32 -0400
Subject: [PATCH] fix(card-master): degrade payload provider gracefully on IO
 error or empty file

---
 .../Services/CardMasterPayloadProvider.cs     | 25 ++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/SVSim.EmulatedEntrypoint/Services/CardMasterPayloadProvider.cs b/SVSim.EmulatedEntrypoint/Services/CardMasterPayloadProvider.cs
index 4cb3b63d..91875a98 100644
--- a/SVSim.EmulatedEntrypoint/Services/CardMasterPayloadProvider.cs
+++ b/SVSim.EmulatedEntrypoint/Services/CardMasterPayloadProvider.cs
@@ -35,8 +35,27 @@ public sealed class CardMasterPayloadProvider : ICardMasterPayloadProvider
             IsAvailable = false;
             return;
         }
-        Base64Blob = File.ReadAllText(path).Trim();
-        IsAvailable = Base64Blob.Length > 0;
-        log.LogInformation("Loaded card-master blob ({Bytes} base64 chars).", Base64Blob.Length);
+        string content;
+        try
+        {
+            content = File.ReadAllText(path).Trim();
+        }
+        catch (IOException ex)
+        {
+            log.LogError(ex, "Failed reading card-master blob at {Path} — /immutable_data/card_master will 503.", path);
+            Base64Blob = "";
+            IsAvailable = false;
+            return;
+        }
+        if (content.Length == 0)
+        {
+            log.LogWarning("Card-master blob at {Path} is empty — /immutable_data/card_master will 503.", path);
+            Base64Blob = "";
+            IsAvailable = false;
+            return;
+        }
+        Base64Blob = content;
+        IsAvailable = true;
+        log.LogInformation("Loaded card-master blob from {Path} ({Bytes} base64 chars).", path, Base64Blob.Length);
     }
 }