Fix directly uploading zero-byte files

Closes #33450.

2 files changed, 2 insertions, 2 deletions

diff --git a/activestorage/app/assets/javascripts/activestorage.js b/activestorage/app/assets/javascripts/activestorage.js
index a22f644238..d3fd795a3a 100644
--- a/activestorage/app/assets/javascripts/activestorage.js
+++ b/activestorage/app/assets/javascripts/activestorage.js
@@ -484,7 +484,7 @@
     }, {
       key: "readNextChunk",
       value: function readNextChunk() {
-        if (this.chunkIndex < this.chunkCount) {
+        if (this.chunkIndex < this.chunkCount || this.chunkIndex == 0 && this.chunkCount == 0) {
           var start = this.chunkIndex * this.chunkSize;
           var end = Math.min(start + this.chunkSize, this.file.size);
           var bytes = fileSlice.call(this.file, start, end);
diff --git a/activestorage/app/javascript/activestorage/file_checksum.js b/activestorage/app/javascript/activestorage/file_checksum.js
index ffaec1a128..d46f276957 100644
--- a/activestorage/app/javascript/activestorage/file_checksum.js
+++ b/activestorage/app/javascript/activestorage/file_checksum.js
@@ -39,7 +39,7 @@ export class FileChecksum {
   }
 
   readNextChunk() {
-    if (this.chunkIndex < this.chunkCount) {
+    if (this.chunkIndex < this.chunkCount || this.chunkIndex == 0 && this.chunkCount == 0) {
       const start = this.chunkIndex * this.chunkSize
       const end = Math.min(start + this.chunkSize, this.file.size)
       const bytes = fileSlice.call(this.file, start, end)