Fixed null reference exceptions

Teknik/Areas/Paste/PasteHelper.cs

@@ -150,7 +150,8 @@ namespace Teknik.Areas.Paste
             {
                 var paste = _pasteCache.GetObject(url, (key) => db.Pastes.FirstOrDefault(up => up.Url == key));
 
-                if (!db.Exists(paste))
+                if (paste != null &&
+                    !db.Exists(paste))
                     db.Attach(paste);
 
                 return paste;
@@ -160,19 +161,22 @@ namespace Teknik.Areas.Paste
         public static void DeleteFile(TeknikEntities db, Config config, ILogger<Logger> logger, string url)
         {
             var paste = GetPaste(db, url);
-            try
-            {
-                var storageService = StorageServiceFactory.GetStorageService(config.PasteConfig.StorageConfig);
-                storageService.DeleteFile(paste.FileName);
-            }
-            catch (Exception ex)
+            if (paste != null)
             {
-                logger.LogError(ex, "Unable to delete file: {0}", paste.FileName);
-            }
+                try
+                {
+                    var storageService = StorageServiceFactory.GetStorageService(config.PasteConfig.StorageConfig);
+                    storageService.DeleteFile(paste.FileName);
+                }
+                catch (Exception ex)
+                {
+                    logger.LogError(ex, "Unable to delete file: {0}", paste.FileName);
+                }
 
-            // Delete from the DB
-            db.Pastes.Remove(paste);
-            db.SaveChanges();
+                // Delete from the DB
+                db.Pastes.Remove(paste);
+                db.SaveChanges();
+            }
 
             // Remove from the cache
             lock (_cacheLock)
@@ -189,12 +193,15 @@ namespace Teknik.Areas.Paste
                 _pasteCache.UpdateObject(paste.Url, paste);
             }
 
-            if (!db.Exists(paste))
-                db.Attach(paste);
+            if (paste != null)
+            {
+                if (!db.Exists(paste))
+                    db.Attach(paste);
 
-            // Update the database
-            db.Entry(paste).State = EntityState.Modified;
-            db.SaveChanges();
+                // Update the database
+                db.Entry(paste).State = EntityState.Modified;
+                db.SaveChanges();
+            }
         }
     }
 }

Teknik/Areas/Upload/Controllers/UploadController.cs

@@ -529,7 +529,7 @@ namespace Teknik.Areas.Upload.Controllers
         [HttpOptions]
         public IActionResult Delete(string id)
         {
-            Models.Upload foundUpload = _dbContext.Uploads.Where(u => u.Url == id).FirstOrDefault();
+            Models.Upload foundUpload = UploadHelper.GetUpload(_dbContext, id);
             if (foundUpload != null)
             {
                 if (foundUpload.User?.Username == User.Identity.Name ||

Teknik/Areas/Upload/UploadHelper.cs

@@ -172,7 +172,8 @@ namespace Teknik.Areas.Upload
             {
                 var upload = _uploadCache.GetObject(url, (key) => db.Uploads.FirstOrDefault(up => up.Url == key));
 
-                if (!db.Exists(upload))
+                if (upload != null &&
+                    !db.Exists(upload))
                     db.Attach(upload);
 
                 return upload;
@@ -182,19 +183,22 @@ namespace Teknik.Areas.Upload
         public static void DeleteFile(TeknikEntities db, Config config, ILogger<Logger> logger, string url)
         {
             var upload = GetUpload(db, url);
-            try
-            {
-                var storageService = StorageServiceFactory.GetStorageService(config.UploadConfig.StorageConfig);
-                storageService.DeleteFile(upload.FileName);
-            }
-            catch (Exception ex)
+            if (upload != null)
             {
-                logger.LogError(ex, "Unable to delete file: {0}", upload.FileName);
-            }
+                try
+                {
+                    var storageService = StorageServiceFactory.GetStorageService(config.UploadConfig.StorageConfig);
+                    storageService.DeleteFile(upload.FileName);
+                }
+                catch (Exception ex)
+                {
+                    logger.LogError(ex, "Unable to delete file: {0}", upload.FileName);
+                }
 
-            // Delete from the DB
-            db.Uploads.Remove(upload);
-            db.SaveChanges();
+                // Delete from the DB
+                db.Uploads.Remove(upload);
+                db.SaveChanges();
+            }
 
             // Remove from the cache
             lock (_cacheLock)
@@ -211,9 +215,15 @@ namespace Teknik.Areas.Upload
                 _uploadCache.UpdateObject(upload.Url, upload);
             }
 
-            // Update the database
-            db.Entry(upload).State = EntityState.Modified;
-            db.SaveChanges();
+            if (upload != null)
+            {
+                if (!db.Exists(upload))
+                    db.Attach(upload);
+
+                // Update the database
+                db.Entry(upload).State = EntityState.Modified;
+                db.SaveChanges();
+            }
         }
     }
 }