Fix attachment scanning for literal text and multiline links

internal/api/export_test.go

@@ -85,3 +85,86 @@ func TestReadTokenMayExportButCannotWrite(t *testing.T) {
 		t.Fatalf("只读令牌获得写权限：%d", code)
 	}
 }
+
+func TestExportDoesNotTreatTextAndFootnotesAsAssets(t *testing.T) {
+	for _, content := range []string{
+		"普通文字 ](private.png)\n",
+		"正文[^1]\n\n[^1]: private.png\n",
+		"\\[转义文字](private.png)\n",
+		"[未闭合链接](private.png\n",
+		"`[代码](private.png)`\n",
+		"正文[^1]\n\n[^1]: 这是脚注内容。\n",
+	} {
+		t.Run(content, func(t *testing.T) {
+			f := newFixture(t)
+			f.write("文章.md", content)
+			if err := os.WriteFile(filepath.Join(f.root, "private.png"), []byte("未选中的私有文件"), 0644); err != nil {
+				t.Fatal(err)
+			}
+			response := f.do(f.admin, "POST", "/api/v1/export", `{"paths":["文章.md"]}`, nil)
+			defer response.Body.Close()
+			body, err := io.ReadAll(response.Body)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if response.StatusCode != 200 || !strings.HasPrefix(response.Header.Get("Content-Type"), "text/markdown") || string(body) != content {
+				t.Fatalf("应只导出原文，不夹带无关文件：%d %s", response.StatusCode, body)
+			}
+		})
+	}
+}
+
+func TestExportIncludesAssetsInMultilineLinksAndContainers(t *testing.T) {
+	for _, content := range []string{
+		"![图片](\nassets/image.png\n)\n",
+		"> ![图片](\n> assets/image.png\n> )\n",
+		"> ![图片][pic]\n>\n> [pic]: assets/image.png\n",
+		"> > ![图片][pic]\n> >\n> > [pic]: assets/image.png\n",
+		"- ![图片][pic]\n\n  [pic]: assets/image.png\n",
+		"![图片][pic]\n\n[pic]:\n  assets/image.png \"说明\"\n",
+		"正文[^1]\n\n[^1]: ![图片](assets/image.png)\n",
+		"![图片][pic]\n\n[pic]: assets/image.png \"[不是链接](private.png)\"\n",
+		"![图片][pic]\n\n[pic]: assets/image.png\n  \"[不是链接](private.png)\"\n",
+		"![图片][pic]\n\n[pic]: assets/image.png \"说明\n[fake]: private.png\n\"\n",
+	} {
+		t.Run(content, func(t *testing.T) {
+			f := newFixture(t)
+			f.write("文章.md", content)
+			if err := os.MkdirAll(filepath.Join(f.root, "assets"), 0755); err != nil {
+				t.Fatal(err)
+			}
+			if err := os.WriteFile(filepath.Join(f.root, "assets/image.png"), []byte("图片内容"), 0644); err != nil {
+				t.Fatal(err)
+			}
+			response := f.do(f.admin, "POST", "/api/v1/export", `{"paths":["文章.md"]}`, nil)
+			defer response.Body.Close()
+			data, err := io.ReadAll(response.Body)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if response.StatusCode != 200 {
+				t.Fatalf("导出失败：%d %s", response.StatusCode, data)
+			}
+			reader, err := zip.NewReader(bytes.NewReader(data), int64(len(data)))
+			if err != nil {
+				t.Fatal("附件不应被漏收：", err)
+			}
+			files := map[string]string{}
+			for _, file := range reader.File {
+				r, err := file.Open()
+				if err != nil {
+					t.Fatal(err)
+				}
+				body, err := io.ReadAll(r)
+				r.Close()
+				if err != nil {
+					t.Fatal(err)
+				}
+				files[file.Name] = string(body)
+			}
+			if len(files) != 2 || files["文章.md"] != content || files["assets/image.png"] != "图片内容" {
+				t.Fatalf("原文或附件不符：%v", files)
+			}
+		})
+	}
+}

internal/vault/export.go

@@ -61,14 +61,8 @@ func (v *Vault) Export(ctx context.Context, paths []string) (result *os.File, na
 		if e != nil {
 			return nil, "", e
 		}
-		var linkError error
-		transformMarkdownLines(content, importRef, func(line []byte) []byte {
-			if linkError != nil {
-				return line
-			}
-			return transformOutsideCode(line, func(text []byte) []byte {
-				for _, span := range importLinkSpans(text) {
-					target := string(text[span.start:span.end])
+		for _, span := range importLinkSpans(content) {
+			target := string(content[span.start:span.end])
 			if span.html {
 				target = html.UnescapeString(target)
 			} else {
@@ -76,8 +70,7 @@ func (v *Vault) Export(ctx context.Context, paths []string) (result *os.File, na
 			}
 			u, e := url.Parse(target)
 			if e != nil {
-						linkError = fmt.Errorf("%w：附件地址无效 %s", ErrInvalidPath, target)
-						break
+				return nil, "", fmt.Errorf("%w：附件地址无效 %s", ErrInvalidPath, target)
 			}
 			if u.IsAbs() || u.Host != "" || strings.HasPrefix(target, "/") || u.Path == "" {
 				continue
@@ -87,24 +80,16 @@ func (v *Vault) Export(ctx context.Context, paths []string) (result *os.File, na
 				continue
 			}
 			if e = v.exportPath(rel); e != nil {
-						linkError = fmt.Errorf("附件 %s：%w", rel, e)
-						break
+				return nil, "", fmt.Errorf("附件 %s：%w", rel, e)
 			}
 			info, e := v.Stat(rel)
 			if e != nil {
-						linkError = fmt.Errorf("附件 %s：%w", rel, e)
-						break
+				return nil, "", fmt.Errorf("附件 %s：%w", rel, e)
 			}
 			if !info.IsDir() {
 				files[rel] = false
 			}
 		}
-				return text
-			})
-		})
-		if linkError != nil {
-			return nil, "", linkError
-		}
 	}
 	tmp, e := os.CreateTemp("", "rawmark-export-*")
 	if e != nil {

internal/vault/images.go

@@ -11,7 +11,6 @@ import (
 	"os"
 	"path"
 	"path/filepath"
-	"sort"
 	"strings"
 )
 
@@ -86,16 +85,14 @@ func rewriteImageLinks(content []byte, note, from, to string) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	transform := func(text []byte) []byte {
-		spans := importLinkSpans(text)
-		sort.Slice(spans, func(i, j int) bool { return spans[i].start < spans[j].start })
+	spans := importLinkSpans(content)
 	var out []byte
 	last := 0
 	for _, span := range spans {
 		if span.start < last {
 			continue
 		}
-			target := string(text[span.start:span.end])
+		target := string(content[span.start:span.end])
 		if span.html {
 			target = html.UnescapeString(target)
 		} else {
@@ -115,11 +112,9 @@ func rewriteImageLinks(content []byte, note, from, to string) ([]byte, error) {
 		if span.html {
 			replacement = html.EscapeString(replacement)
 		}
-			out = append(out, text[last:span.start]...)
+		out = append(out, content[last:span.start]...)
 		out = append(out, replacement...)
 		last = span.end
 	}
-		return append(out, text[last:]...)
-	}
-	return transformMarkdownLines(content, importRef, func(line []byte) []byte { return transformOutsideCode(line, transform) }), nil
+	return append(out, content[last:]...), nil
 }

internal/vault/images_test.go

@@ -53,6 +53,29 @@ func TestImageMoveUpdatesLocalReferences(t *testing.T) {
 	f.Close()
 }
 
+func TestImageMovePreservesMultilineMarkdownAndIgnoresLiteralPaths(t *testing.T) {
+	v := newVault(t)
+	if err := os.WriteFile(filepath.Join(v.Root(), "old.png"), []byte("image"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	content := "> ![图片][pic]\r\n>\r\n> [pic]: old.png \"[示例](old.png)\"\r\n\n![跨行](\nold.png\n)\n\n普通文字 ](old.png)\n\n[^1]: old.png\n\n`![代码](old.png)`\n\n> ```md\n> ![代码块](old.png)\n> ```\n"
+	if _, err := v.Write("文章.md", []byte(content), Precondition{}); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := v.Move("old.png", "new.png", nil); err != nil {
+		t.Fatal(err)
+	}
+	body, _, err := v.Read("文章.md")
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := strings.Replace(content, "[pic]: old.png", "[pic]: new.png", 1)
+	want = strings.Replace(want, "![跨行](\nold.png", "![跨行](\nnew.png", 1)
+	if string(body) != want {
+		t.Fatalf("应只改写真正的图片引用：\n%s\n期望：\n%s", body, want)
+	}
+}
+
 func TestReplaceImagePreservesPathAndUploadContents(t *testing.T) {
 	v := newVault(t)
 	link, err := v.SaveAsset("a.md", "old.png", strings.NewReader("original"), 100)

internal/vault/import_links.go

@@ -15,7 +15,7 @@ import (
 	"strings"
 )
 
-var importRef = regexp.MustCompile(`^ {0,3}\[[^\]\r\n]+\]:[ \t]*`)
+var importRef = regexp.MustCompile(`(?m)^ {0,3}\[[^\[\]\r\n]+\]:[ \t]*`)
 var importSrc = regexp.MustCompile(`(?i)<(?:img|source|video|audio)\b[^>]*?\bsrc\s*=\s*["']([^"']*)["']`)
 var markdownEscape = regexp.MustCompile("\\\\([!\"#$%&'()*+,\\-./:;<=>?@\\[\\]\\\\^_`{|}~])")
 
@@ -24,101 +24,222 @@ type importLink struct {
 	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++
+// 链接中的空白允许一次换行，但不能跨过段落。
+func linkSpace(text []byte, pos int) int {
+	newline := false
+	for pos < len(text) {
+		switch text[pos] {
+		case ' ', '\t', '\r':
+		case '\n':
+			if newline {
+				return pos
 			}
+			newline = true
+		default:
+			return pos
+		}
+		pos++
+	}
+	return pos
+}
+
+// linkDestination 返回地址区间和地址结束后的下标；地址本身不含尖括号。
+func linkDestination(text []byte, pos int) (start, end, next int) {
+	start = linkSpace(text, pos)
 	if start == len(text) {
-		return start, start
+		return start, 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) {
+		for end = start + 1; end < len(text); end++ {
+			switch text[end] {
+			case '\\':
+				if end+1 < len(text) {
 					end++
 				}
-			end++
+			case '>':
+				return start + 1, end, end + 1
+			case '<', '\n', '\r', 0:
+				return start, start, start
 			}
-		if end < len(text) && text[end] == '>' {
-			return start + 1, end
 		}
-		return start, start
+		return start, start, start
 	}
 	depth := 0
-	end := start
-	for end < len(text) {
+	for end = start; end < len(text); end++ {
 		c := text[end]
 		if c == '\\' && end+1 < len(text) {
-			end += 2
+			end++
 			continue
 		}
 		if c == '(' {
 			depth++
-		}
-		if c == ')' {
+		} else if c == ')' {
 			if depth == 0 {
 				break
 			}
 			depth--
-		}
-		if c == ' ' || c == '\t' || c == '\n' || c == '\r' {
+		} else if c <= ' ' || c == '<' || c == 0x7f {
 			break
 		}
-		end++
 	}
 	if depth != 0 {
-		return start, start
+		return start, start, start
 	}
-	return start, end
+	return start, end, 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})
+func linkTitleEnd(text []byte, pos int) int {
+	quote := text[pos]
+	close := quote
+	if quote == '(' {
+		close = ')'
 	}
-	}
-	for pos := 0; pos < len(text); {
-		i := bytes.Index(text[pos:], []byte("]("))
-		if i < 0 {
+	for i := pos + 1; i < len(text); i++ {
+		if text[i] == '\\' && i+1 < len(text) {
+			i++
+		} else if text[i] == close {
+			return i + 1
+		} else if (quote == '(' && text[i] == '(') || (text[i] == '\n' && linkSpace(text, i) < len(text) && text[linkSpace(text, i)] == '\n') {
 			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})
+	return -1
+}
+
+// importLinkSpans 共用于导入、导出和图片改名；返回原文字节位置，不重新序列化正文。
+func importLinkSpans(content []byte) []importLink {
+	var text []byte
+	var source []int
+	lastEnd := 0
+	transformMarkdownLines(content, importRef, func(line, body []byte, offset int) []byte {
+		if len(text) > 0 && offset != lastEnd {
+			text = append(text, '\n', '\n')
+			source = append(source, -1, -1)
+		}
+		start := offset + len(line) - len(body)
+		text = append(text, body...)
+		for i := range body {
+			source = append(source, start+i)
+		}
+		lastEnd = offset + len(line)
+		return line
+	})
+	// 行内代码可以跨行。遮住其中的标记，同时保留链接标签两侧的括号结构。
+	masked := bytes.Repeat([]byte(" "), len(text))
+	pos := 0
+	for _, paragraph := range bytes.SplitAfter(text, []byte("\n\n")) {
+		transformOutsideCode(paragraph, func(part []byte, offset int) []byte {
+			copy(masked[pos+offset:], part)
+			return part
+		})
+		pos += len(paragraph)
+	}
+	text = masked
+	var spans []importLink
+	add := func(start, end int, html bool) {
+		spans = append(spans, importLink{source[start], source[end-1] + 1, html})
+	}
+	definitionEnd := 0
+	for _, m := range importRef.FindAllIndex(text, -1) {
+		if m[0] < definitionEnd {
+			continue
+		}
+		label := bytes.TrimSpace(text[m[0]:m[1]])
+		if bytes.HasPrefix(label, []byte("[^")) || len(bytes.TrimSpace(label[1:bytes.IndexByte(label, ']')])) == 0 {
+			continue
+		}
+		start, end, next := linkDestination(text, m[1])
+		if end == start {
+			continue
+		}
+		titleStart := linkSpace(text, next)
+		if titleStart > next && titleStart < len(text) && (text[titleStart] == '"' || text[titleStart] == '\'' || text[titleStart] == '(') {
+			titleEnd := linkTitleEnd(text, titleStart)
+			if titleEnd >= 0 {
+				for titleEnd < len(text) && (text[titleEnd] == ' ' || text[titleEnd] == '\t' || text[titleEnd] == '\r') {
+					titleEnd++
+				}
+				if titleEnd == len(text) || text[titleEnd] == '\n' {
+					next = titleEnd
+				}
+			}
+		}
+		for next < len(text) && (text[next] == ' ' || text[next] == '\t' || text[next] == '\r') {
+			next++
+		}
+		if next < len(text) && text[next] != '\n' {
+			continue
+		}
+		add(start, end, false)
+		definitionEnd = next
+		// 引用定义及其标题不是行内正文，避免再次扫描标题中的示例标记。
+		for i := m[0]; i < next; i++ {
+			if text[i] != '\n' && text[i] != '\r' {
+				text[i] = ' '
+			}
+		}
+	}
+	var brackets []int
+	for i := 0; i < len(text); i++ {
+		switch text[i] {
+		case '\\':
+			i++
+		case '\n':
+			if next := linkSpace(text, i); next < len(text) && text[next] == '\n' {
+				brackets = nil
+			}
+		case '[':
+			brackets = append(brackets, i)
+		case ']':
+			if len(brackets) == 0 {
+				continue
+			}
+			open := brackets[len(brackets)-1]
+			brackets = brackets[:len(brackets)-1]
+			if i+1 == len(text) || text[i+1] != '(' {
+				continue
+			}
+			start, end, next := linkDestination(text, i+2)
+			if end == start {
+				continue
+			}
+			close := linkSpace(text, next)
+			if close > next && close < len(text) && (text[close] == '"' || text[close] == '\'' || text[close] == '(') {
+				close = linkTitleEnd(text, close)
+				if close < 0 {
+					continue
+				}
+				close = linkSpace(text, close)
+			}
+			if close < len(text) && text[close] == ')' {
+				add(start, end, false)
+				i = close
+				if open == 0 || text[open-1] != '!' {
+					brackets = nil // 链接不能嵌套，图片可以位于链接标签内。
+				}
+			}
 		}
-		pos = max(i+2, end)
 	}
 	for _, m := range importSrc.FindAllSubmatchIndex(text, -1) {
-		spans = append(spans, importLink{m[2], m[3], true})
+		if m[3] > m[2] {
+			add(m[2], m[3], true)
 		}
+	}
+	sort.Slice(spans, func(i, j int) bool { return spans[i].start < spans[j].start })
 	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 })
+	spans := importLinkSpans(content)
 	var out []byte
 	last := 0
 	for _, span := range spans {
-			if span.start < last || failure != nil {
+		if span.start < last {
 			continue
 		}
-			raw := string(text[span.start:span.end])
+		raw := string(content[span.start:span.end])
 		target := raw
 		if span.html {
 			target = html.UnescapeString(target)
@@ -140,8 +261,7 @@ func (v *Vault) importLinks(ctx context.Context, note string, content []byte, to
 			continue
 		}
 		if err != nil {
-				failure = err
-				continue
+			return nil, nil, err
 		}
 		if !info.Mode().IsRegular() {
 			continue
@@ -152,36 +272,30 @@ func (v *Vault) importLinks(ctx context.Context, note string, content []byte, to
 		replacement, found := replacements[rel]
 		if !found {
 			if err := ctx.Err(); err != nil {
-					failure = err
-					continue
+				return nil, nil, err
 			}
 			data, err := os.ReadFile(filepath.Join(v.root, filepath.FromSlash(rel)))
 			if err != nil {
-					failure = err
-					continue
+				return nil, nil, err
 			}
 			// 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
+				return nil, nil, readErr
 			}
 			if readErr == nil && !bytes.Equal(data, existing) {
-					failure = fmt.Errorf("%w：附件名称与内容冲突", ErrInvalidImport)
-					continue
+				return nil, nil, fmt.Errorf("%w：附件名称与内容冲突", ErrInvalidImport)
 			}
 			if os.IsNotExist(readErr) {
 				if int64(len(data)) > maxImportExpanded-*total {
-						failure = ErrTooLarge
-						continue
+					return nil, nil, ErrTooLarge
 				}
 				*total += int64(len(data))
 			}
 			replacement, err = v.SaveAsset(note, path.Base(rel), bytes.NewReader(data), importAssetLimit)
 			if err != nil {
-					failure = err
-					continue
+				return nil, nil, err
 			}
 			replacements[rel] = replacement
 		}
@@ -194,16 +308,14 @@ func (v *Vault) importLinks(ctx context.Context, note string, content []byte, to
 		if span.html {
 			replacement = html.EscapeString(replacement)
 		}
-			out = append(out, text[last:span.start]...)
+		out = append(out, content[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) })
+	updated := append(out, content[last:]...)
 	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
+	return updated, warnings, nil
 }

internal/vault/import_test.go

@@ -89,6 +89,33 @@ func TestImportZipAssetsAndMove(t *testing.T) {
 	}
 }
 
+func TestImportPreservesContainersAndOnlyRewritesActualLinks(t *testing.T) {
+	v := newVault(t)
+	content := "> ![图片][pic]\r\n>\r\n> [pic]: assets/image.png \"[示例](private.png)\"\r\n\n![跨行](\nassets/image.png\n)\n\n普通文字 ](private.png)\n\n[^1]: missing.png\n\n`![代码](assets/image.png)`\n"
+	source := importZip(t,
+		zipEntry{name: "文章.md", content: content},
+		zipEntry{name: "assets/image.png", content: "image"},
+		zipEntry{name: "private.png", content: "private"},
+	)
+	result, err := v.Import(context.Background(), "", "导入", []ImportFile{source})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if result.Notes != 1 || result.Assets != 3 || len(result.Warnings) != 0 {
+		t.Fatalf("仅真实图片应生成附件副本，脚注正文不应产生缺失警告：%+v", result)
+	}
+	body, _, err := v.Read("导入/文章.md")
+	if err != nil {
+		t.Fatal(err)
+	}
+	link := EscapeLinkPath("文章.assets") + "/" + assetName([]byte("image"), "x.png")
+	want := strings.Replace(content, "[pic]: assets/image.png", "[pic]: "+link, 1)
+	want = strings.Replace(want, "![跨行](\nassets/image.png", "![跨行](\n"+link, 1)
+	if string(body) != want {
+		t.Fatalf("应只改写真实链接并保留原文格式：\n%s\n期望：\n%s", body, want)
+	}
+}
+
 func TestImportRejectsInvalidWithoutPublishing(t *testing.T) {
 	for _, tc := range []struct {
 		name    string

internal/vault/links.go

@@ -16,21 +16,25 @@ 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 {
+	return transformMarkdownLines(content, refDef, func(line, _ []byte, _ int) []byte {
 		line = refDef.ReplaceAll(line, repl)
-		return transformOutsideCode(line, func(text []byte) []byte { return inline.ReplaceAll(text, repl) })
+		return transformOutsideCode(line, func(text []byte, _ int) []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 {
+func transformMarkdownLines(content []byte, refDef *regexp.Regexp, transform func(line, body []byte, offset int) []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
 	paragraph := false
+	lineOffset := 0
 	for i, line := range lines {
+		offset := lineOffset
+		lineOffset += len(line)
 		// 分类时展开制表符，替换仍作用于原始字节，不重新序列化 Markdown。
 		body := bytes.TrimRight(expandLinkTabs(line), "\r\n")
+		width := len(body)
 		matched := 0
 		for _, container := range containers {
 			indent := len(body) - len(bytes.TrimLeft(body, " "))
@@ -119,7 +123,17 @@ func transformMarkdownLines(content []byte, refDef *regexp.Regexp, transform fun
 			continue
 		}
 		paragraph = !paragraphBoundary.Match(trimmed) && !refDef.Match(trimmed)
-		lines[i] = transform(line)
+		// 将剥离容器时的展开列数映射回原始字节，保留制表符和正文位置。
+		start, column := 0, 0
+		for column < width-len(body) {
+			if line[start] == '\t' {
+				column += 4 - column%4
+			} else {
+				column++
+			}
+			start++
+		}
+		lines[i] = transform(line, line[start:], offset)
 	}
 	return bytes.Join(lines, nil)
 }
@@ -169,8 +183,9 @@ func fenceOpen(line []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 {
+func transformOutsideCode(line []byte, transform func(text []byte, offset int) []byte) []byte {
 	var out []byte
+	offset := 0
 	for len(line) > 0 {
 		start := bytes.IndexByte(line, '`')
 		if start < 0 {
@@ -185,9 +200,10 @@ func transformOutsideCode(line []byte, transform func([]byte) []byte) []byte {
 			break
 		}
 		codeEnd := start + n + end + n
-		out = append(out, transform(line[:start])...)
+		out = append(out, transform(line[:start], offset)...)
 		out = append(out, line[start:codeEnd]...)
 		line = line[codeEnd:]
+		offset += codeEnd
 	}
-	return append(out, transform(line)...)
+	return append(out, transform(line, offset)...)
 }