Add a check to see if we already hit EOF on Read

upload.go

@@ -140,10 +140,19 @@ func processUpload(upReq UploadRequest) (upload Upload, err error) {
 	barename, extension := barePlusExt(upReq.filename)
 
 	// Pull the first 512 bytes off for use in MIME detection if needed
+	// If the file uploaded fit in 512 or less bytes, then the Read will have returned EOF
+	// In this situation we don't want to create a MultiReader as this will cause no EOF to be emitted
+	// by the resulting io.Reader. Instead we just create a new reader from the bytes we already read,
+	// and only create a multiReader if we have yet to get EOF from the first read.
+	var fileSrc io.Reader
 	header := make([]byte, 512)
 	n, err := upReq.src.Read(header)
-	if n == 0 || err != nil {
+	if n == 0 {
 		return
+	} else if err == io.EOF {
+		fileSrc = bytes.NewReader(header[:n])
+	} else {
+		fileSrc = io.MultiReader(bytes.NewReader(header), upReq.src)
 	}
 
 	if upReq.randomBarename || len(barename) == 0 {
@@ -199,10 +208,7 @@ func processUpload(upReq UploadRequest) (upload Upload, err error) {
 
 	metadataWrite(upload.Filename, &upload)
 
-	// Make a multi-reader from the header and the remainder of bytes
+	bytes, err := io.Copy(dst, fileSrc)
-	// in the upReq.src io.Reader
-	src := io.MultiReader(bytes.NewReader(header), upReq.src)
-	bytes, err := io.Copy(dst, src)
 	if err != nil {
 		return
 	} else if bytes == 0 {