siyuan-note/siyuan · error

invalid rich clipboard asset count

Error message

invalid rich clipboard asset count [%d]

What it means

PrepareRichClipboardAssets (kernel/model/clipboard.go:68) validates that a rich-clipboard copy carries a non-empty batch of at most 1024 assets; otherwise it returns fmt.Errorf("invalid rich clipboard asset count [%d]", len(assets)). The guard `len(assets) < 1 || 1024 < len(assets)` rejects both empty payloads and oversized ones before any filesystem work starts. On failure the prepared batch is discarded via the deferred cleanupRichClipboardGroups.

Solutions

1. Check the caller: skip the kernel call entirely when the collected asset list is empty and show a normal (non-rich) paste path
2. Chunk or deduplicate the asset list to stay at or below 1024 entries before calling PrepareRichClipboardAssets
3. Log the actual count from the error message and inspect why so many entries were collected (dedupe by asset path)
4. Treat the returned error as a caller-input validation failure; no retry will help

Example fix

// before
prepared, err := model.PrepareRichClipboardAssets(allAssets) // may be 5000 entries

// after
if len(allAssets) == 0 || len(allAssets) > 1024 {
    return fmt.Errorf("rich clipboard payload must contain 1..1024 assets, got %d", len(allAssets))
}
prepared, err := model.PrepareRichClipboardAssets(allAssets)

if len(assets) < 1 || len(assets) > 1024 {
    return fmt.Errorf("asset count %d out of range 1..1024", len(assets))
}

When it happens

Trigger: Calling PrepareRichClipboardAssets with an empty slice (nothing copied) or with more than 1024 RichClipboardAsset entries — e.g. pasting a document containing thousands of images in one operation.

Common situations: Frontend submitting an empty assets array when the clipboard parse found no images; batch-pasting very large HTML/exports with >1024 image references; a loop bug that duplicates entries past the cap.

Understand the failure class

Background: "value must be between 0 and 1" / "out of range" / "must not be negative" errors: fixing range-validation failures across open-source libraries — this error's family across 42 libraries.

Related errors

• createDocTree exceeds the maximum depth of
• Field [assets. .box] should be of type [String]
• Field [assets. ] should be of type [Object]
• Field [assets] must not be empty
• Field [batch] must not be empty

AI-assisted analysis of siyuan-note/siyuan@9f775e8a12 (2026-09-19). Data as JSON: /api/errors/74e4fc437d2023e4. Report an issue: GitHub.

Appendix: source

Thrown at kernel/model/clipboard.go:68

	Index int
	Path  string
	Box   string
}

type RichClipboardPreparedAsset struct {
	Index int    `json:"index"`
	Path  string `json:"path"`
}

type RichClipboardPrepared struct {
	Batch  string                       `json:"batch"`
	Groups []string                     `json:"groups"`
	Assets []RichClipboardPreparedAsset `json:"assets"`
}

func PrepareRichClipboardAssets(assets []RichClipboardAsset) (ret *RichClipboardPrepared, err error) {
	if len(assets) < 1 || 1024 < len(assets) {
		return nil, fmt.Errorf("invalid rich clipboard asset count [%d]", len(assets))
	}

	batch := util.RandString(24)
	groups := map[string]struct{}{}
	copied := map[string]string{}
	ret = &RichClipboardPrepared{Batch: batch}
	defer func() {
		if err != nil {
			cleanupRichClipboardGroups(batch, groups)
		}
	}()

	for _, asset := range assets {
		if asset.Index < 0 {
			return nil, fmt.Errorf("invalid rich clipboard asset index [%d]", asset.Index)
		}

		ext := strings.ToLower(filepath.Ext(AssetPathWithoutQuery(asset.Path)))

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