From c8d5f335b1d0d4c461a6bf214da01b5041f58532 Mon Sep 17 00:00:00 2001
From: Leo Vasanko <leo@git>
Date: Mon, 13 Nov 2023 02:00:44 -0800
Subject: [PATCH] Fix upload of zero-sized files.

---
 cista/api.py                             | 13 ++++++++++---
 cista/fileio.py                          |  6 ++++--
 frontend/src/components/UploadButton.vue |  5 +----
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/cista/api.py b/cista/api.py
index c97d893..99da767 100644
--- a/cista/api.py
+++ b/cista/api.py
@@ -37,16 +37,23 @@ async def upload(req, ws):
             )
         req = msgspec.json.decode(text, type=FileRange)
         pos = req.start
-        data = None
-        while pos < req.end and (data := await ws.recv()) and isinstance(data, bytes):
+        while True:
+            data = await ws.recv()
+            if not isinstance(data, bytes):
+                break
+            if len(data) > req.end - pos:
+                raise ValueError(
+                    f"Expected up to {req.end - pos} bytes, got {len(data)} bytes"
+                )
             sentsize = await alink(("upload", req.name, pos, data, req.size))
             pos += typing.cast(int, sentsize)
+            if pos >= req.end:
+                break
         if pos != req.end:
             d = f"{len(data)} bytes" if isinstance(data, bytes) else data
             raise ValueError(f"Expected {req.end - pos} more bytes, got {d}")
         # Report success
         res = StatusMsg(status="ack", req=req)
-        print("ack", res)
         await asend(ws, res)
 
 
diff --git a/cista/fileio.py b/cista/fileio.py
index 8a821d2..b9052f8 100644
--- a/cista/fileio.py
+++ b/cista/fileio.py
@@ -34,9 +34,11 @@ class File:
             self.open_rw()
         assert self.fd is not None
         if file_size is not None:
+            assert pos + len(buffer) <= file_size
             os.ftruncate(self.fd, file_size)
-        os.lseek(self.fd, pos, os.SEEK_SET)
-        os.write(self.fd, buffer)
+        if buffer:
+            os.lseek(self.fd, pos, os.SEEK_SET)
+            os.write(self.fd, buffer)
 
     def __getitem__(self, slice):
         if self.fd is None:
diff --git a/frontend/src/components/UploadButton.vue b/frontend/src/components/UploadButton.vue
index 32d7ea0..39dd239 100644
--- a/frontend/src/components/UploadButton.vue
+++ b/frontend/src/components/UploadButton.vue
@@ -166,10 +166,6 @@ const worker = async () => {
   const ws = await WSCreate()
   while (upqueue.length) {
     const f = upqueue[0]
-    if (f.cloudPos === f.file.size) {
-      upqueue.shift()
-      continue
-    }
     const start = f.cloudPos
     const end = Math.min(f.file.size, start + (1<<20))
     const control = { name: f.cloudName, size: f.file.size, start, end }
@@ -180,6 +176,7 @@ const worker = async () => {
     ws.sendMsg(control)
     // @ts-ignore
     await ws.sendData(data)
+    if (f.cloudPos === f.file.size) upqueue.shift()
   }
   if (upqueue.length) startWorker()
   uprogress.status = "idle"