feat(编辑能力): 修复字体外置残留与版本清理

ofdgo_editor_font_cleanup.go

@@ -0,0 +1,103 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"maps"
+	"slices"
+)
+
+// compactVersionFonts 清理仅由版本清单保留的无引用字体，同步清单且不修改编辑器快照
+// 入参: ctx 取消上下文, parts 输出修改, removed 待删除条目
+// 返回: error 读取、结构或取消错误
+func (e *Editor) compactVersionFonts(ctx context.Context, parts map[string][]byte, removed map[string]bool) error {
+	reader := e.source.reader
+	versioned := false
+	for _, body := range reader.OFD.DocBody {
+		versioned = versioned || body.versioned
+	}
+	if !versioned {
+		return nil
+	}
+	protected, err := reader.hasOutputSignatures()
+	if err != nil || protected {
+		return err
+	}
+	view := &Reader{Zip: reader.Zip, files: maps.Clone(reader.files)}
+	if view.files == nil {
+		view.files = make(map[string][]byte)
+	}
+	maps.Copy(view.files, parts)
+	if err := view.initRoot(); err != nil {
+		return err
+	}
+	candidates, seen := make(map[string]bool), make(map[string]bool)
+	for index := range view.DocumentCount() {
+		view.documentIndex = index
+		versions, err := view.DocumentVersions()
+		if err != nil {
+			return err
+		}
+		for _, version := range versions {
+			for _, file := range version.Files {
+				if err := ctx.Err(); err != nil {
+					return err
+				}
+				name := file.Location
+				if seen[name] || removed[name] {
+					continue
+				}
+				seen[name] = true
+				input, err := view.openFile(name)
+				if err != nil {
+					return err
+				}
+				var header [4]byte
+				n, err := io.ReadFull(input, header[:])
+				input.Close()
+				if err != nil && err != io.EOF && err != io.ErrUnexpectedEOF {
+					return err
+				}
+				if n == len(header) {
+					switch string(header[:]) {
+					case "\x00\x01\x00\x00", "OTTO", "ttcf":
+						candidates[name] = true
+					}
+				}
+			}
+		}
+	}
+	if len(candidates) == 0 {
+		return nil
+	}
+	if err := pruneExternalFontFiles(ctx, view, slices.Collect(maps.Keys(candidates))...); err != nil {
+		return err
+	}
+	for name, data := range view.files {
+		if original, ok := reader.files[name]; !ok || !bytes.Equal(original, data) {
+			parts[name] = data
+		}
+	}
+	for name := range candidates {
+		if !view.fileNames[name] {
+			removed[name] = true
+			delete(parts, name)
+		}
+	}
+	return nil
+}