#upload 4 articles

• Overwrite=true into a folder shared by many records silently replaces — and takes over — another record's filegotchas / rest-apiUploading with Files/AddUsingPath(…,Overwrite=true) under a user-supplied file name into a folder that holds documents of many records (cases, orders, tickets) lets a second file with the same generic name (such as…
• Dropping a folder onto your upload zone does nothing (dataTransfer.files never sees it)gotchas / spfxdataTransfer.files cannot see a folder, items is neutered after the first await, and readEntries() returns the contents in batches of 100
• File upload via /Files/add: nometadata works under OData v4 — an empty OData-Version breaks SPFx when you leave out Content-Typegotchas / rest-apinometadata + octet-stream under the default OData v4; an empty OData-Version without Content-Type throws inside SPHttpClient; plus the empty-filename mobile camera trap
• Uploaded .html grows after you set column values — SharePoint injects mso document properties (and rewrites Office files on upload)gotchas / rest-apiSetting column values rewrites the file; hash read-back fails for markup, holds for PDF; Office packages change on upload itself…