From 740449394c4fe7c00756c635eb6b8b1ebd79acb5 Mon Sep 17 00:00:00 2001
From: Laila Los <44241786+ElectronicBlueberry@users.noreply.github.com>
Date: Fri, 15 Mar 2024 16:49:05 +0100
Subject: [PATCH] add edge case for element_count bug

---
 client/src/stores/collectionElementsStore.ts | 29 ++++++++++++--------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/client/src/stores/collectionElementsStore.ts b/client/src/stores/collectionElementsStore.ts
index d265becded8b..ac04e1839611 100644
--- a/client/src/stores/collectionElementsStore.ts
+++ b/client/src/stores/collectionElementsStore.ts
@@ -74,19 +74,25 @@ export const useCollectionElementsStore = defineStore("collectionElementsStore",
         const collectionKey = getCollectionKey(collection);
 
         try {
-            // We should fetch only missing (placeholder) elements from the range
-            const firstMissingIndexInRange = storedElements
-                .slice(offset, offset + limit)
-                .findIndex((element) => (isPlaceholder(element) && !element.fetching) || isInvalid(element));
+            if (storedElements.length !== 0) {
+                // We should fetch only missing (placeholder) elements from the range
+                const firstMissingIndexInRange = storedElements
+                    .slice(offset, offset + limit)
+                    .findIndex((element) => (isPlaceholder(element) && !element.fetching) || isInvalid(element));
+
+                if (firstMissingIndexInRange === -1) {
+                    // All elements in the range are already stored or being fetched
+                    return;
+                }
 
-            if (firstMissingIndexInRange === -1) {
-                // All elements in the range are already stored or being fetched
-                return;
+                // Adjust the offset to the first missing element
+                offset += firstMissingIndexInRange;
+            } else {
+                // Edge case where element_count is incorrect
+                // TODO: remove me once element_count is reported reliably
+                offset = 0;
             }
 
-            // Adjust the offset to the first missing element
-            offset += firstMissingIndexInRange;
-
             set(loadingCollectionElements.value, collectionKey, true);
             // Mark all elements in the range as fetching
             storedElements
@@ -124,7 +130,8 @@ export const useCollectionElementsStore = defineStore("collectionElementsStore",
                 const to = from + data.fetchedElements.length;
 
                 for (let index = from; index < to; index++) {
-                    set(storedElements, index, ensureDefined(data.fetchedElements[index - from]));
+                    const element = ensureDefined(data.fetchedElements[index - from]);
+                    set(storedElements, index, element);
                 }
 
                 set(storedCollectionElements.value, key, storedElements);