Add Markdown and ZIP notebook import

internal/vault/import.go

@@ -0,0 +1,289 @@
+package vault
+
+import (
+	"archive/zip"
+	"bytes"
+	"compress/flate"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"path"
+	"path/filepath"
+	"sort"
+	"strings"
+	"syscall"
+	"unicode/utf8"
+)
+
+const (
+	MaxImportBytes    = 100_000_000
+	maxImportExpanded = 512 << 20
+	maxImportEntries  = 10_000
+	importNoteLimit   = 20 << 20
+	importAssetLimit  = 50 << 20
+)
+
+var ErrInvalidImport = errors.New("导入内容无效")
+
+// ImportFile 的读取范围是单个上传文件，ZIP 与普通 Markdown 共用这一输入边界。
+type ImportFile struct {
+	Name   string
+	Reader io.ReaderAt
+	Size   int64
+}
+
+type ImportResult struct {
+	Paths    []string `json:"paths"`
+	Notes    int      `json:"notes"`
+	Assets   int      `json:"assets"`
+	Warnings []string `json:"warnings"`
+}
+
+// Import 在隐藏目录内整理完整内容，提交前统一检查冲突，绝不覆盖已有文件。
+func (v *Vault) Import(ctx context.Context, dir, folder string, files []ImportFile) (result ImportResult, err error) {
+	result = ImportResult{Paths: []string{}, Warnings: []string{}}
+	if len(files) == 0 || len(files) > maxImportEntries {
+		return result, fmt.Errorf("%w：请选择 Markdown 文件或一个 ZIP", ErrInvalidImport)
+	}
+	zipped := len(files) == 1 && strings.EqualFold(path.Ext(files[0].Name), ".zip")
+	if zipped {
+		if _, err := CleanPath(folder); err != nil || strings.Contains(folder, "/") || strings.HasSuffix(folder, AssetsExt) {
+			return result, fmt.Errorf("%w：导入文件夹名称无效", ErrInvalidImport)
+		}
+	} else if folder != "" {
+		return result, fmt.Errorf("%w：普通 Markdown 不使用外层文件夹", ErrInvalidImport)
+	}
+	if dir != "" {
+		if _, err := CleanPath(dir); err != nil {
+			return result, err
+		}
+	}
+	var uploadBytes int64
+	for _, f := range files {
+		if f.Size < 0 || f.Size > MaxImportBytes-uploadBytes {
+			return result, ErrTooLarge
+		}
+		uploadBytes += f.Size
+	}
+	stage, err := os.MkdirTemp(v.root, tmpPrefix+"import-")
+	if err != nil {
+		return result, err
+	}
+	defer func() {
+		if cleanup := os.RemoveAll(stage); cleanup != nil {
+			err = errors.Join(err, fmt.Errorf("清理导入临时目录失败：%w", cleanup))
+		}
+	}()
+	staged := &Vault{root: stage}
+	entries := map[string]struct{}{}
+	var total int64
+	var notes []string
+	// 每个来源文件只写一次；目录与文件重名也会在暂存阶段报错。
+	write := func(name string, isDir bool, reader io.Reader) error {
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+		if _, err := CleanPath(name); err != nil || !utf8.ValidString(name) {
+			return fmt.Errorf("%w：ZIP 含有非法路径", ErrInvalidImport)
+		}
+		if _, exists := entries[name]; exists {
+			return fmt.Errorf("%w：存在重复路径", ErrInvalidImport)
+		}
+		entries[name] = struct{}{}
+		dest := filepath.Join(stage, filepath.FromSlash(name))
+		if isDir {
+			err := os.MkdirAll(dest, 0o755)
+			if errors.Is(err, fs.ErrExist) || errors.Is(err, syscall.ENOTDIR) {
+				return fmt.Errorf("%w：文件与目录路径冲突", ErrInvalidImport)
+			}
+			return err
+		}
+		if err := os.MkdirAll(filepath.Dir(dest), 0o755); err != nil {
+			if errors.Is(err, syscall.ENOTDIR) || errors.Is(err, fs.ErrExist) {
+				return fmt.Errorf("%w：文件与目录路径冲突", ErrInvalidImport)
+			}
+			return err
+		}
+		f, err := os.OpenFile(dest, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0o644)
+		if err != nil {
+			if errors.Is(err, fs.ErrExist) || errors.Is(err, syscall.ENOTDIR) {
+				return fmt.Errorf("%w：文件与目录路径冲突", ErrInvalidImport)
+			}
+			return err
+		}
+		limit := int64(importAssetLimit)
+		if IsNote(name) {
+			limit = importNoteLimit
+			notes = append(notes, name)
+		}
+		limit = min(limit, maxImportExpanded-total)
+		n, copyErr := io.Copy(f, io.LimitReader(reader, limit+1))
+		closeErr := f.Close()
+		total += n
+		if n > limit {
+			return ErrTooLarge
+		}
+		return errors.Join(copyErr, closeErr)
+	}
+	if zipped {
+		z, err := zip.NewReader(files[0].Reader, files[0].Size)
+		if err != nil {
+			return result, fmt.Errorf("%w：无法读取 ZIP：%w", ErrInvalidImport, err)
+		}
+		if len(z.File) > maxImportEntries {
+			return result, ErrTooLarge
+		}
+		for _, f := range z.File {
+			if !f.Mode().IsRegular() && !f.Mode().IsDir() {
+				return result, fmt.Errorf("%w：ZIP 不允许符号链接或特殊文件", ErrInvalidImport)
+			}
+			name := strings.TrimSuffix(f.Name, "/")
+			r, err := f.Open()
+			if err != nil {
+				return result, fmt.Errorf("%w：无法读取 ZIP 条目：%w", ErrInvalidImport, err)
+			}
+			err = write(name, f.FileInfo().IsDir(), r)
+			err = errors.Join(err, r.Close())
+			if err != nil {
+				var corrupt flate.CorruptInputError
+				if errors.Is(err, zip.ErrChecksum) || errors.Is(err, io.ErrUnexpectedEOF) || errors.As(err, &corrupt) {
+					err = fmt.Errorf("%w：ZIP 内容损坏：%w", ErrInvalidImport, err)
+				}
+				return result, err
+			}
+		}
+	} else {
+		for _, f := range files {
+			if !IsNote(f.Name) || strings.Contains(f.Name, "/") {
+				return result, fmt.Errorf("%w：只接受 .md 文件或单个 ZIP", ErrInvalidImport)
+			}
+			if err := write(f.Name, false, io.NewSectionReader(f.Reader, 0, f.Size)); err != nil {
+				return result, err
+			}
+		}
+	}
+	if len(notes) == 0 {
+		return result, fmt.Errorf("%w：没有可导入的 Markdown 笔记", ErrInvalidImport)
+	}
+	sort.Strings(notes)
+	for _, note := range notes {
+		if err := ctx.Err(); err != nil {
+			return result, err
+		}
+		for _, seg := range strings.Split(path.Dir(note), "/") {
+			if strings.HasSuffix(seg, AssetsExt) {
+				return result, fmt.Errorf("%w：笔记不能放在 .assets 附件目录内", ErrInvalidImport)
+			}
+		}
+		content, _, err := staged.Read(note)
+		if err != nil {
+			return result, err
+		}
+		if !utf8.Valid(content) || bytes.IndexByte(content, 0) >= 0 {
+			return result, fmt.Errorf("%w：Markdown 必须是 UTF-8 文本", ErrInvalidImport)
+		}
+		content = bytes.TrimPrefix(content, []byte{0xef, 0xbb, 0xbf})
+		updated, warnings, err := staged.importLinks(ctx, note, content, &total)
+		if err != nil {
+			return result, err
+		}
+		result.Warnings = append(result.Warnings, warnings...)
+		if len(updated) > importNoteLimit || total+int64(len(updated)-len(content)) > maxImportExpanded {
+			return result, ErrTooLarge
+		}
+		total += int64(len(updated) - len(content))
+		if err := os.WriteFile(filepath.Join(stage, filepath.FromSlash(note)), updated, 0o644); err != nil {
+			return result, err
+		}
+	}
+	result.Notes = len(notes)
+	// 附件数量包含原始附件及为各笔记生成的独立副本。
+	count := 0
+	err = filepath.WalkDir(stage, func(p string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		count++
+		if count > maxImportEntries+1 {
+			return ErrTooLarge
+		}
+		if !d.IsDir() && !IsNote(d.Name()) {
+			result.Assets++
+		}
+		return nil
+	})
+	if err != nil {
+		return result, err
+	}
+	top, err := os.ReadDir(stage)
+	if err != nil {
+		return result, err
+	}
+	targets := []string{}
+	if zipped {
+		targets = append(targets, path.Join(dir, folder))
+	} else {
+		for _, f := range top {
+			targets = append(targets, path.Join(dir, f.Name()))
+		}
+	}
+	v.mu.Lock()
+	defer v.mu.Unlock()
+	parent := v.root
+	if dir != "" {
+		parent, err = v.abs(dir)
+		if err != nil {
+			return result, err
+		}
+	}
+	info, err := os.Stat(parent)
+	if errors.Is(err, fs.ErrNotExist) {
+		return result, ErrNotFound
+	}
+	if err != nil {
+		return result, err
+	}
+	if !info.IsDir() {
+		return result, fmt.Errorf("%w：目标不是文件夹", ErrInvalidImport)
+	}
+	for _, target := range targets {
+		dest, err := v.abs(target)
+		if err != nil {
+			return result, err
+		}
+		if _, err := os.Lstat(dest); err == nil {
+			return result, fmt.Errorf("%w：%s，请修改名称", ErrExists, target)
+		} else if !errors.Is(err, fs.ErrNotExist) {
+			return result, err
+		}
+	}
+	if err := ctx.Err(); err != nil {
+		return result, err
+	}
+	if zipped {
+		// 暂存目录与仓库位于同一文件系统，整个 ZIP 一次 rename 发布。
+		err = os.Rename(stage, filepath.Join(parent, folder))
+	} else {
+		var published []string
+		for _, f := range top {
+			name := f.Name()
+			if err = os.Rename(filepath.Join(stage, name), filepath.Join(parent, name)); err != nil {
+				for _, prev := range published {
+					if rollback := os.Rename(filepath.Join(parent, prev), filepath.Join(stage, prev)); rollback != nil {
+						err = errors.Join(err, fmt.Errorf("回滚导入失败：%w", rollback))
+					}
+				}
+				break
+			}
+			published = append(published, name)
+		}
+	}
+	if err != nil {
+		return result, err
+	}
+	result.Paths = targets
+	return result, nil
+}

internal/vault/import_links.go

@@ -0,0 +1,211 @@
+package vault
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"html"
+	"net/url"
+	"os"
+	"path"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+var importRef = regexp.MustCompile(`^ {0,3}\[[^\]\r\n]+\]:[ \t]*`)
+var importSrc = regexp.MustCompile(`(?i)<(?:img|source|video|audio)\b[^>]*?\bsrc\s*=\s*["']([^"']*)["']`)
+var markdownEscape = regexp.MustCompile("\\\\([!\"#$%&'()*+,\\-./:;<=>?@\\[\\]\\\\^_`{|}~])")
+
+type importLink struct {
+	start, end int
+	html       bool
+}
+
+// linkDestination 返回目的地址本身的区间，不含尖括号、标题或闭合括号。
+func linkDestination(text []byte, start int) (int, int) {
+	for start < len(text) && (text[start] == ' ' || text[start] == '\t') {
+		start++
+	}
+	if start == len(text) {
+		return start, start
+	}
+	if text[start] == '<' {
+		end := start + 1
+		for end < len(text) && text[end] != '>' && text[end] != '\n' && text[end] != '\r' {
+			if text[end] == '\\' && end+1 < len(text) {
+				end++
+			}
+			end++
+		}
+		if end < len(text) && text[end] == '>' {
+			return start + 1, end
+		}
+		return start, start
+	}
+	depth := 0
+	end := start
+	for end < len(text) {
+		c := text[end]
+		if c == '\\' && end+1 < len(text) {
+			end += 2
+			continue
+		}
+		if c == '(' {
+			depth++
+		}
+		if c == ')' {
+			if depth == 0 {
+				break
+			}
+			depth--
+		}
+		if c == ' ' || c == '\t' || c == '\n' || c == '\r' {
+			break
+		}
+		end++
+	}
+	if depth != 0 {
+		return start, start
+	}
+	return start, end
+}
+
+func importLinkSpans(text []byte) []importLink {
+	var spans []importLink
+	if m := importRef.FindIndex(text); m != nil {
+		start, end := linkDestination(text, m[1])
+		if end > start {
+			spans = append(spans, importLink{start, end, false})
+		}
+	}
+	for pos := 0; pos < len(text); {
+		i := bytes.Index(text[pos:], []byte("]("))
+		if i < 0 {
+			break
+		}
+		i += pos
+		// 转义的闭括号不是链接语法。
+		escapes := 0
+		for j := i - 1; j >= 0 && text[j] == '\\'; j-- {
+			escapes++
+		}
+		start, end := linkDestination(text, i+2)
+		if escapes%2 == 0 && end > start {
+			spans = append(spans, importLink{start, end, false})
+		}
+		pos = max(i+2, end)
+	}
+	for _, m := range importSrc.FindAllSubmatchIndex(text, -1) {
+		spans = append(spans, importLink{m[2], m[3], true})
+	}
+	return spans
+}
+
+func (v *Vault) importLinks(ctx context.Context, note string, content []byte, total *int64) ([]byte, []string, error) {
+	var failure error
+	missing := map[string]bool{}
+	replacements := map[string]string{}
+	transform := func(text []byte) []byte {
+		spans := importLinkSpans(text)
+		// 区间可能来自 HTML 或 Markdown，按原始顺序替换，保持其他字节不变。
+		sort.Slice(spans, func(i, j int) bool { return spans[i].start < spans[j].start })
+		var out []byte
+		last := 0
+		for _, span := range spans {
+			if span.start < last || failure != nil {
+				continue
+			}
+			raw := string(text[span.start:span.end])
+			target := raw
+			if span.html {
+				target = html.UnescapeString(target)
+			} else {
+				target = markdownEscape.ReplaceAllString(target, "$1")
+			}
+			u, err := url.Parse(target)
+			if err != nil || u.IsAbs() || u.Host != "" || strings.HasPrefix(target, "/") || u.Path == "" {
+				continue
+			}
+			rel := path.Clean(path.Join(path.Dir(note), u.Path))
+			if _, err := CleanPath(rel); err != nil {
+				missing[rel] = true
+				continue
+			}
+			info, err := os.Stat(filepath.Join(v.root, filepath.FromSlash(rel)))
+			if os.IsNotExist(err) {
+				missing[rel] = true
+				continue
+			}
+			if err != nil {
+				failure = err
+				continue
+			}
+			if !info.Mode().IsRegular() {
+				continue
+			}
+			switch strings.ToLower(path.Ext(rel)) {
+			case ".png", ".jpg", ".jpeg", ".gif", ".webp", ".svg", ".avif", ".apng", ".bmp", ".ico", ".tif", ".tiff":
+			default:
+				continue
+			}
+			replacement, found := replacements[rel]
+			if !found {
+				if err := ctx.Err(); err != nil {
+					failure = err
+					continue
+				}
+				data, err := os.ReadFile(filepath.Join(v.root, filepath.FromSlash(rel)))
+				if err != nil {
+					failure = err
+					continue
+				}
+				// 只统计新生成的副本；已有同名附件必须与哈希对应的内容一致。
+				dest := filepath.Join(v.root, filepath.FromSlash(AssetsDir(note)), assetName(data, path.Base(rel)))
+				existing, readErr := os.ReadFile(dest)
+				if readErr != nil && !os.IsNotExist(readErr) {
+					failure = readErr
+					continue
+				}
+				if readErr == nil && !bytes.Equal(data, existing) {
+					failure = fmt.Errorf("%w：附件名称与内容冲突", ErrInvalidImport)
+					continue
+				}
+				if os.IsNotExist(readErr) {
+					if int64(len(data)) > maxImportExpanded-*total {
+						failure = ErrTooLarge
+						continue
+					}
+					*total += int64(len(data))
+				}
+				replacement, err = v.SaveAsset(note, path.Base(rel), bytes.NewReader(data), importAssetLimit)
+				if err != nil {
+					failure = err
+					continue
+				}
+				replacements[rel] = replacement
+			}
+			if u.RawQuery != "" {
+				replacement += "?" + u.RawQuery
+			}
+			if u.Fragment != "" {
+				replacement += "#" + u.EscapedFragment()
+			}
+			if span.html {
+				replacement = html.EscapeString(replacement)
+			}
+			out = append(out, text[last:span.start]...)
+			out = append(out, replacement...)
+			last = span.end
+		}
+		return append(out, text[last:]...)
+	}
+	updated := transformMarkdownLines(content, importRef, func(line []byte) []byte { return transformOutsideCode(line, transform) })
+	warnings := []string{}
+	if len(missing) > 0 {
+		warnings = append(warnings, note+"："+strconv.Itoa(len(missing))+" 个本地链接的目标不在导入内容中，已保留原链接")
+	}
+	return updated, warnings, failure
+}

internal/vault/import_test.go

@@ -0,0 +1,204 @@
+package vault
+
+import (
+	"archive/zip"
+	"bytes"
+	"context"
+	"errors"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+type zipEntry struct {
+	name, content string
+	mode          fs.FileMode
+}
+
+func importZip(t *testing.T, entries ...zipEntry) ImportFile {
+	t.Helper()
+	var b bytes.Buffer
+	w := zip.NewWriter(&b)
+	for _, e := range entries {
+		h := &zip.FileHeader{Name: e.name, Method: zip.Deflate}
+		if e.mode != 0 {
+			h.SetMode(e.mode)
+		}
+		f, err := w.CreateHeader(h)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if _, err := f.Write([]byte(e.content)); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := w.Close(); err != nil {
+		t.Fatal(err)
+	}
+	data := b.Bytes()
+	return ImportFile{Name: "知识库.md.zip", Reader: bytes.NewReader(data), Size: int64(len(data))}
+}
+
+func markdownFile(name, content string) ImportFile {
+	return ImportFile{Name: name, Reader: strings.NewReader(content), Size: int64(len(content))}
+}
+
+func TestImportZipAssetsAndMove(t *testing.T) {
+	v := newVault(t)
+	content := "# 标题\n\n![图](<assets/图 (1).png> \"说明\")\n\n![引用][图]\n\n[图]: assets/图%20(1).png\n\n<img src=\"assets/图%20(1).png\">\n\n[子笔记](子目录/子笔记.md)\n\n![外链](https://example.com/a.png)\n\n![缺失](assets/missing.png)\n\n`![代码](assets/图%20(1).png)`\n\n```md\n![代码块](assets/图%20(1).png)\n```\n\n> ```\n> ![引用代码](assets/图%20(1).png)\n> ```\n\n    ![缩进代码](assets/图%20(1).png)\n"
+	source := importZip(t, zipEntry{name: "目录/笔记.md", content: content}, zipEntry{name: "目录/子目录/子笔记.md", content: "# 子笔记"}, zipEntry{name: "目录/assets/图 (1).png", content: "image"}, zipEntry{name: "未引用.txt", content: "附件"})
+	result, err := v.Import(context.Background(), "", "知识库", []ImportFile{source})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if result.Notes != 2 || result.Assets != 3 || len(result.Warnings) != 1 || len(result.Paths) != 1 || result.Paths[0] != "知识库" {
+		t.Fatalf("结果不符: %+v", result)
+	}
+	body, _, err := v.Read("知识库/目录/笔记.md")
+	if err != nil {
+		t.Fatal(err)
+	}
+	link := EscapeLinkPath("笔记.assets") + "/" + assetName([]byte("image"), "x.png")
+	expected := strings.Replace(content, "<assets/图 (1).png>", "<"+link+">", 1)
+	expected = strings.Replace(expected, "[图]: assets/图%20(1).png", "[图]: "+link, 1)
+	expected = strings.Replace(expected, "src=\"assets/图%20(1).png\"", "src=\""+link+"\"", 1)
+	if string(body) != expected {
+		t.Fatalf("正文变更不符:\n%s", body)
+	}
+	if err := v.Mkdir("移动目标"); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := v.Move("知识库/目录/笔记.md", "移动目标/改名.md"); err != nil {
+		t.Fatal(err)
+	}
+	moved, _, err := v.Read("移动目标/改名.md")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(string(moved), "改名.assets/") {
+		t.Fatal("图片链接未跟随改名")
+	}
+	if _, err := os.Stat(filepath.Join(v.root, "移动目标/改名.assets", assetName([]byte("image"), "x.png"))); err != nil {
+		t.Fatal("附件未跟随", err)
+	}
+	original, err := os.ReadFile(filepath.Join(v.root, "知识库/目录/assets/图 (1).png"))
+	if err != nil || string(original) != "image" {
+		t.Fatal("原始附件丢失", err)
+	}
+}
+
+func TestImportRejectsInvalidWithoutPublishing(t *testing.T) {
+	for _, tc := range []struct {
+		name    string
+		entries []zipEntry
+		want    error
+	}{
+		{"越界", []zipEntry{{name: "../outside.md", content: "x"}}, ErrInvalidImport},
+		{"隐藏路径", []zipEntry{{name: ".rawmark/x.md", content: "x"}}, ErrInvalidImport},
+		{"重复路径", []zipEntry{{name: "a.md", content: "x"}, {name: "a.md", content: "y"}}, ErrInvalidImport},
+		{"符号链接", []zipEntry{{name: "a.md", content: "x", mode: os.ModeSymlink | 0o777}}, ErrInvalidImport},
+		{"目录文件冲突", []zipEntry{{name: "a/"}, {name: "a", content: "x"}, {name: "b.md", content: "x"}}, ErrInvalidImport},
+		{"文件目录冲突反向", []zipEntry{{name: "a", content: "x"}, {name: "a/"}, {name: "b.md", content: "x"}}, ErrInvalidImport},
+		{"无笔记", []zipEntry{{name: "a.png", content: "x"}}, ErrInvalidImport},
+		{"非法编码", []zipEntry{{name: "a.md", content: "\xff"}}, ErrInvalidImport},
+		{"附件目录内笔记", []zipEntry{{name: "a.assets/a.md", content: "x"}}, ErrInvalidImport},
+		{"文件目录冲突", []zipEntry{{name: "a", content: "x"}, {name: "a/b.md", content: "y"}}, ErrInvalidImport},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			v := newVault(t)
+			_, err := v.Import(context.Background(), "", "导入", []ImportFile{importZip(t, tc.entries...)})
+			if !errors.Is(err, tc.want) {
+				t.Fatalf("错误不符: %v", err)
+			}
+			entries, err := os.ReadDir(v.root)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if len(entries) != 1 || entries[0].Name() != metaDir {
+				t.Fatal("失败后留下可见内容或临时目录")
+			}
+		})
+	}
+}
+
+func TestImportBatchConflictAndCancellation(t *testing.T) {
+	v := newVault(t)
+	if _, err := v.Write("b.md", []byte("原文"), Precondition{}); err != nil {
+		t.Fatal(err)
+	}
+	sources := []ImportFile{markdownFile("a.md", "新文"), markdownFile("b.md", "覆盖")}
+	if _, err := v.Import(context.Background(), "", "", sources); !errors.Is(err, ErrExists) {
+		t.Fatal(err)
+	}
+	if _, _, err := v.Read("a.md"); !errors.Is(err, ErrNotFound) {
+		t.Fatal("批量冲突产生了半成品", err)
+	}
+	body, _, _ := v.Read("b.md")
+	if string(body) != "原文" {
+		t.Fatal("原文件被覆盖")
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	if _, err := v.Import(ctx, "", "", sources[:1]); !errors.Is(err, context.Canceled) {
+		t.Fatal(err)
+	}
+	if _, err := v.Import(context.Background(), "不存在", "", sources[:1]); !errors.Is(err, ErrNotFound) {
+		t.Fatal(err)
+	}
+	result, err := v.Import(context.Background(), "", "", []ImportFile{markdownFile("a.md", "\xef\xbb\xbf正文"), markdownFile("c.md", "![缺图](local.png)")})
+	if err != nil || result.Notes != 2 || len(result.Warnings) != 1 {
+		t.Fatalf("结果不符: %+v %v", result, err)
+	}
+	body, _, _ = v.Read("a.md")
+	if string(body) != "正文" {
+		t.Fatal("UTF-8 BOM 未处理")
+	}
+}
+
+func TestImportLimitsAndCorruptZip(t *testing.T) {
+	v := newVault(t)
+	source := markdownFile("large.md", strings.Repeat("a", importNoteLimit+1))
+	if _, err := v.Import(context.Background(), "", "", []ImportFile{source}); !errors.Is(err, ErrTooLarge) {
+		t.Fatal(err)
+	}
+	source.Size = MaxImportBytes + 1
+	if _, err := v.Import(context.Background(), "", "", []ImportFile{source}); !errors.Is(err, ErrTooLarge) {
+		t.Fatal(err)
+	}
+	broken := markdownFile("broken.zip", "not zip")
+	if _, err := v.Import(context.Background(), "", "导入", []ImportFile{broken}); !errors.Is(err, ErrInvalidImport) {
+		t.Fatal(err)
+	}
+}
+
+func TestImportCorruptZipContent(t *testing.T) {
+	v := newVault(t)
+	var buffer bytes.Buffer
+	writer := zip.NewWriter(&buffer)
+	f, err := writer.CreateHeader(&zip.FileHeader{Name: "n.md", Method: zip.Store})
+	if err != nil {
+		t.Fatal(err)
+	}
+	payload := []byte("unique markdown payload")
+	if _, err := f.Write(payload); err != nil {
+		t.Fatal(err)
+	}
+	if err := writer.Close(); err != nil {
+		t.Fatal(err)
+	}
+	data := buffer.Bytes()
+	offset := bytes.Index(data, payload)
+	if offset < 0 {
+		t.Fatal("找不到测试负载")
+	}
+	data[offset] ^= 1
+	_, err = v.Import(context.Background(), "", "损坏", []ImportFile{{Name: "broken.zip", Reader: bytes.NewReader(data), Size: int64(len(data))}})
+	if !errors.Is(err, ErrInvalidImport) {
+		t.Fatalf("应拒绝 CRC 损坏: %v", err)
+	}
+	if _, err := os.Stat(filepath.Join(v.root, "损坏")); !os.IsNotExist(err) {
+		t.Fatal("损坏内容被发布", err)
+	}
+}

internal/vault/links.go

@@ -16,6 +16,14 @@ func RewriteAssetLinks(content []byte, oldBase, newBase string) []byte {
 	refDef := regexp.MustCompile(`^( {0,3}\[[^\]]+\]:\s*<?)` + target)
 	repl := []byte("${1}${2}" + strings.ReplaceAll(EscapeLinkPath(newBase+AssetsExt), "$", "$$") + "/")
 
+	return transformMarkdownLines(content, refDef, func(line []byte) []byte {
+		line = refDef.ReplaceAll(line, repl)
+		return transformOutsideCode(line, func(text []byte) []byte { return inline.ReplaceAll(text, repl) })
+	})
+}
+
+// transformMarkdownLines 复用链接改写的容器与代码块识别，避免导入时修改代码示例。
+func transformMarkdownLines(content []byte, refDef *regexp.Regexp, transform func([]byte) []byte) []byte {
 	lines := bytes.SplitAfter(content, []byte("\n"))
 	var fence []byte // 当前所在围栏代码块的围栏字符串，nil 表示不在代码块中
 	var containers []linkContainer
@@ -111,8 +119,7 @@ func RewriteAssetLinks(content []byte, oldBase, newBase string) []byte {
 			continue
 		}
 		paragraph = !paragraphBoundary.Match(trimmed) && !refDef.Match(trimmed)
-		line = refDef.ReplaceAll(line, repl)
-		lines[i] = replaceOutsideCode(line, inline, repl)
+		lines[i] = transform(line)
 	}
 	return bytes.Join(lines, nil)
 }
@@ -161,8 +168,8 @@ func fenceOpen(line []byte) []byte {
 	return rest[:n]
 }
 
-// replaceOutsideCode 只在行内代码 `…` 之外的片段上做替换
-func replaceOutsideCode(line []byte, re *regexp.Regexp, repl []byte) []byte {
+// transformOutsideCode 只在行内代码 `…` 之外的片段上做转换。
+func transformOutsideCode(line []byte, transform func([]byte) []byte) []byte {
 	var out []byte
 	for len(line) > 0 {
 		start := bytes.IndexByte(line, '`')
@@ -178,9 +185,9 @@ func replaceOutsideCode(line []byte, re *regexp.Regexp, repl []byte) []byte {
 			break
 		}
 		codeEnd := start + n + end + n
-		out = append(out, re.ReplaceAll(line[:start], repl)...)
+		out = append(out, transform(line[:start])...)
 		out = append(out, line[start:codeEnd]...)
 		line = line[codeEnd:]
 	}
-	return append(out, re.ReplaceAll(line, repl)...)
+	return append(out, transform(line)...)
 }

internal/vault/vault.go

@@ -696,12 +696,7 @@ func (v *Vault) SaveAsset(note, origName string, r io.Reader, limit int64) (stri
 	if int64(len(data)) > limit {
 		return "", ErrTooLarge
 	}
-	ext := strings.ToLower(filepath.Ext(origName))
-	if !extPattern.MatchString(ext) {
-		ext = sniffExt(data)
-	}
-	sum := sha256.Sum256(data)
-	name := hex.EncodeToString(sum[:8]) + ext
+	name := assetName(data, origName)
 	dir := AssetsDir(p)
 	v.mu.Lock()
 	defer v.mu.Unlock()
@@ -722,6 +717,15 @@ func (v *Vault) SaveAsset(note, origName string, r io.Reader, limit int64) (stri
 	return EscapeLinkPath(path.Base(AssetsDir(note))) + "/" + name, nil
 }
 
+func assetName(data []byte, origName string) string {
+	ext := strings.ToLower(filepath.Ext(origName))
+	if !extPattern.MatchString(ext) {
+		ext = sniffExt(data)
+	}
+	sum := sha256.Sum256(data)
+	return hex.EncodeToString(sum[:8]) + ext
+}
+
 func sniffExt(data []byte) string {
 	switch http.DetectContentType(data) {
 	case "image/png":