vendor: import KillerPDF 1.7.5 source (GPL-3.0) as the base for MMD PDF

2026-08-27 06:58:22 +02:00
commit 532485a830
577 changed files with 149058 additions and 0 deletions
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+using PdfSharpCore.Pdf;
+
+namespace KillerPDF.Services
+{
+    // ============================================================
+    // Outline/bookmark document helpers - pure functions over the
+    // PdfSharpCore outline tree, no window state. Split out of
+    // SidebarOutline.cs (KillerUI refactor); the TreeView panel and
+    // bookmark editing UI stay in the shell.
+    // ============================================================
+    internal static class PdfOutlines
+    {
+        /// <summary>
+        /// #133: PdfSharpCore's lexer decodes UTF-16 bookmark titles by their BOM, but strings it
+        /// decrypts AFTER parsing (owner-password protected files) never get that BOM re-check, so
+        /// the title arrives as raw bytes widened to chars: a U+00FE U+00FF prefix (the BOM bytes)
+        /// followed by one char per byte (mojibake).
+        /// Detect the widened BOM, re-pack the chars into bytes, and decode as UTF-16. Titles that
+        /// parsed correctly don't start with those two chars and pass through untouched.
+        /// </summary>
+        internal static string FixRawUnicodeTitle(string s)
+        {
+            if (s.Length < 2) return s;
+            bool be = s[0] == '\u00FE' && s[1] == '\u00FF';   // UTF-16BE BOM as raw chars
+            bool le = s[0] == '\u00FF' && s[1] == '\u00FE';   // UTF-16LE (Adobe tolerance)
+            if (!be && !le) return s;
+            foreach (char c in s)
+                if (c > '\u00FF') return s;   // not byte-widened data - a real (odd) title, leave it
+            var sb = new System.Text.StringBuilder((s.Length - 2) / 2);
+            for (int i = 2; i + 1 < s.Length; i += 2)   // a trailing odd byte is dropped rather than corrupting the pairs
+                sb.Append(be ? (char)((s[i] << 8) | s[i + 1])
+                             : (char)((s[i + 1] << 8) | s[i]));
+            return sb.ToString();
+        }
+
+        internal static int CountOutlines(PdfSharpCore.Pdf.PdfOutlineCollection col)
+        {
+            int n = 0;
+            foreach (PdfSharpCore.Pdf.PdfOutline o in col) n += 1 + CountOutlines(o.Outlines);
+            return n;
+        }
+
+        // Bottom-up: Collection.Remove() drops the removed object from the document's reference
+        // table, so deleting the whole branch leaf-first leaves no orphaned outline objects (with
+        // dangling /Parent refs) behind in the saved file.
+        internal static void RemoveOutlineRecursive(PdfSharpCore.Pdf.PdfOutlineCollection parent,
+                                                    PdfSharpCore.Pdf.PdfOutline outline)
+        {
+            while (outline.Outlines.Count > 0)
+                RemoveOutlineRecursive(outline.Outlines, outline.Outlines[outline.Outlines.Count - 1]);
+            parent.Remove(outline);
+        }
+
+        // PdfSharpCore's PrepareForSave rewrites outline linkage keys (/First /Last /Next /Prev
+        // /Parent /Count) from the in-memory collections but never REMOVES entries that no longer
+        // apply: an item that became last keeps its old /Next, a parent whose children were all
+        // deleted keeps /First /Last, and an emptied root would dangle (ScrubEmptyOutlines only
+        // drops the catalog entry when /First is gone). After any bookmark edit, strip the linkage
+        // keys everywhere - the writer rebuilds all of them from the collections on save.
+        internal static void ScrubStaleOutlineLinkKeys(PdfDocument? doc)
+        {
+            if (doc is null) return;
+            try
+            {
+                var item = doc.Internals.Catalog.Elements["/Outlines"];
+                if (item is null) return;
+                if (PdfScrub.DerefItemStatic(item) is PdfDictionary root)
+                {
+                    root.Elements.Remove("/First");
+                    root.Elements.Remove("/Last");
+                    root.Elements.Remove("/Count");
+                }
+                ScrubOutlineLinkKeys(doc.Outlines);
+            }
+            catch { /* malformed outline tree - the save-time scrubs are the backstop */ }
+        }
+
+        private static void ScrubOutlineLinkKeys(PdfSharpCore.Pdf.PdfOutlineCollection col)
+        {
+            foreach (PdfSharpCore.Pdf.PdfOutline o in col)
+            {
+                o.Elements.Remove("/First");
+                o.Elements.Remove("/Last");
+                o.Elements.Remove("/Next");
+                o.Elements.Remove("/Prev");
+                o.Elements.Remove("/Parent");
+                o.Elements.Remove("/Count");
+                ScrubOutlineLinkKeys(o.Outlines);
+            }
+        }
+    }
+}