maxMemoryBytes -= int64(len(name))
		maxMemoryBytes -= mapEntryOverhead
		if maxMemoryBytes < 0 {
			// We can't actually take this path, since nextPart would already have
			// rejected the MIME headers for being too large. Check anyway.
			apiErr := errorCodes.ToAPIErr(ErrMalformedPOSTRequest)
			apiErr.Description = fmt.Sprintf("%s (%v)", apiErr.Description, multipart.ErrMessageTooLarge)
			writeErrorResponse(ctx, w, apiErr, r.URL)
			return