From cdc936d2d5df6c0d4d6c22afe7c8b26bc5acbd98 Mon Sep 17 00:00:00 2001
From: Leo Vasanko <leo@git>
Date: Sun, 5 Nov 2023 16:49:24 +0000
Subject: [PATCH] Fix bug when browsing around the end

---
 cista-front/src/components/FileExplorer.vue | 22 ++++++++++-----------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/cista-front/src/components/FileExplorer.vue b/cista-front/src/components/FileExplorer.vue
index 45ea629..17694cc 100644
--- a/cista-front/src/components/FileExplorer.vue
+++ b/cista-front/src/components/FileExplorer.vue
@@ -205,23 +205,21 @@ defineExpose({
       cursor.value = null
       return
     }
+    const N = documents.length
     const mod = (a: number, b: number) => ((a % b) + b) % b
-    const index = cursor.value !== null ? documents.indexOf(cursor.value) : -1
-    const moveto = mod(index + d, documents.length + 1)
+    const increment = (i: number, d: number) => mod(i + d, N + 1)
+    const index = cursor.value !== null ? documents.indexOf(cursor.value) : documents.length
+    const moveto = increment(index, d)
     cursor.value = documents[moveto] ?? null
-    const tr = document.getElementById(
-      `file-${cursor.value.key}`
-    ) as HTMLTableRowElement | null
+    const tr = cursor.value ? document.getElementById(`file-${cursor.value.key}`) : null
     if (select) {
       // Go forwards, possibly wrapping over the end; the last entry is not toggled
       let [begin, end] = d > 0 ? [index, moveto] : [moveto, index]
-      for (let p = begin; p !== end; p = mod(p + 1, documents.length)) {
-        const doc = documents[p]
-        if (documentStore.selected.has(doc.key)) {
-          documentStore.selected.delete(doc.key)
-        } else {
-          documentStore.selected.add(doc.key)
-        }
+      for (let p = begin; p !== end; p = increment(p, 1)) {
+        if (p === N) continue
+        const key = documents[p].key
+        if (documentStore.selected.has(key)) documentStore.selected.delete(key)
+        else documentStore.selected.add(key)
       }
     }
     // @ts-ignore