Update docx, pptx, and xlsx skills (#1447)

Add support for template formats (.dotx, .potx, .xltx) across validation
and the helper scripts.

Consolidate the shared office helpers into a single module, replacing the
pack/unpack pipeline with explicit zip/unzip steps. Extraction now rejects
symlink and path-traversal archive entries. Move run merging to a
standalone docx script, since it only ever applied to Word documents.

Fix the redlining validator so it compares against the original even when
a document has no tracked changes, which is when an untracked edit would
otherwise go unreported.

Provision a LibreOffice user profile per invocation so conversions work in
sandboxed environments.

Trim the skill docs to the guidance that earns its place.

skills/pptx/scripts/clean.py

@@ -15,13 +15,30 @@ This script removes:
 - Content-Type overrides for deleted files
 """
 
+import posixpath
+import re
 import sys
 from pathlib import Path
 
 import defusedxml.minidom
 
+from office.helpers import SLIDE_REL_TYPE, opc_target, rels_source_part
 
-import re
+
+def _slide_rids(pres_rels_path: Path, unpacked_dir: Path) -> dict[str, str]:
+    source_part = rels_source_part(pres_rels_path, unpacked_dir)
+    rels_dom = defusedxml.minidom.parse(str(pres_rels_path))
+
+    rids: dict[str, str] = {}
+    for rel in rels_dom.getElementsByTagName("Relationship"):
+        if rel.getAttribute("Type") != SLIDE_REL_TYPE:
+            continue
+        part = opc_target(
+            rel.getAttribute("Target"), source_part, rel.getAttribute("TargetMode")
+        )
+        if part is not None:
+            rids[rel.getAttribute("Id")] = part
+    return rids
 
 
 def get_slides_in_sldidlst(unpacked_dir: Path) -> set[str]:
@@ -31,19 +48,20 @@ def get_slides_in_sldidlst(unpacked_dir: Path) -> set[str]:
     if not pres_path.exists() or not pres_rels_path.exists():
         return set()
 
-    rels_dom = defusedxml.minidom.parse(str(pres_rels_path))
-    rid_to_slide = {}
-    for rel in rels_dom.getElementsByTagName("Relationship"):
-        rid = rel.getAttribute("Id")
-        target = rel.getAttribute("Target")
-        rel_type = rel.getAttribute("Type")
-        if "slide" in rel_type and target.startswith("slides/"):
-            rid_to_slide[rid] = target.replace("slides/", "")
+    rid_to_slide = _slide_rids(pres_rels_path, unpacked_dir)
 
     pres_content = pres_path.read_text(encoding="utf-8")
     referenced_rids = set(re.findall(r'<p:sldId[^>]*r:id="([^"]+)"', pres_content))
 
-    return {rid_to_slide[rid] for rid in referenced_rids if rid in rid_to_slide}
+    return {
+        posixpath.basename(rid_to_slide[rid])
+        for rid in referenced_rids
+        if rid in rid_to_slide
+    }
+
+
+class RefusedToClean(Exception):
+    """The package does not look the way a readable package should."""
 
 
 def remove_orphaned_slides(unpacked_dir: Path) -> list[str]:
@@ -55,9 +73,25 @@ def remove_orphaned_slides(unpacked_dir: Path) -> list[str]:
         return []
 
     referenced_slides = get_slides_in_sldidlst(unpacked_dir)
+    on_disk = sorted(slides_dir.glob("slide*.xml"))
+
+    if on_disk and not any(s.name in referenced_slides for s in on_disk):
+        listed = re.findall(
+            r'<p:sldId[^>]*r:id="([^"]+)"',
+            (unpacked_dir / "ppt" / "presentation.xml").read_text(encoding="utf-8")
+            if (unpacked_dir / "ppt" / "presentation.xml").exists()
+            else "",
+        )
+        if listed:
+            raise RefusedToClean(
+                f"<p:sldIdLst> lists {len(listed)} slide(s) and none of the "
+                f"{len(on_disk)} slide(s) on disk match any of them. Refusing to "
+                f"delete them all — this is a parse failure, not an empty deck."
+            )
+
     removed = []
 
-    for slide_file in slides_dir.glob("slide*.xml"):
+    for slide_file in on_disk:
         if slide_file.name not in referenced_slides:
             rel_path = slide_file.relative_to(unpacked_dir)
             slide_file.unlink()
@@ -70,16 +104,21 @@ def remove_orphaned_slides(unpacked_dir: Path) -> list[str]:
 
     if removed and pres_rels_path.exists():
         rels_dom = defusedxml.minidom.parse(str(pres_rels_path))
+        source_part = rels_source_part(pres_rels_path, unpacked_dir)
         changed = False
 
         for rel in list(rels_dom.getElementsByTagName("Relationship")):
-            target = rel.getAttribute("Target")
-            if target.startswith("slides/"):
-                slide_name = target.replace("slides/", "")
-                if slide_name not in referenced_slides:
-                    if rel.parentNode:
-                        rel.parentNode.removeChild(rel)
-                        changed = True
+            if rel.getAttribute("Type") != SLIDE_REL_TYPE:
+                continue
+            part = opc_target(
+                rel.getAttribute("Target"), source_part, rel.getAttribute("TargetMode")
+            )
+            if part is None:
+                continue
+            if posixpath.basename(part) not in referenced_slides:
+                if rel.parentNode:
+                    rel.parentNode.removeChild(rel)
+                    changed = True
 
         if changed:
             with open(pres_rels_path, "wb") as f:
@@ -103,24 +142,18 @@ def remove_trash_directory(unpacked_dir: Path) -> list[str]:
     return removed
 
 
-def get_slide_referenced_files(unpacked_dir: Path) -> set:
+def _referenced_by(rels_files, unpacked_dir: Path) -> set:
     referenced = set()
-    slides_rels_dir = unpacked_dir / "ppt" / "slides" / "_rels"
 
-    if not slides_rels_dir.exists():
-        return referenced
-
-    for rels_file in slides_rels_dir.glob("*.rels"):
+    for rels_file in rels_files:
+        source_part = rels_source_part(rels_file, unpacked_dir)
         dom = defusedxml.minidom.parse(str(rels_file))
         for rel in dom.getElementsByTagName("Relationship"):
-            target = rel.getAttribute("Target")
-            if not target:
-                continue
-            target_path = (rels_file.parent.parent / target).resolve()
-            try:
-                referenced.add(target_path.relative_to(unpacked_dir.resolve()))
-            except ValueError:
-                pass
+            part = opc_target(
+                rel.getAttribute("Target"), source_part, rel.getAttribute("TargetMode")
+            )
+            if part is not None:
+                referenced.add(Path(part))
 
     return referenced
 
@@ -128,7 +161,6 @@ def get_slide_referenced_files(unpacked_dir: Path) -> set:
 def remove_orphaned_rels_files(unpacked_dir: Path) -> list[str]:
     resource_dirs = ["charts", "diagrams", "drawings"]
     removed = []
-    slide_referenced = get_slide_referenced_files(unpacked_dir)
 
     for dir_name in resource_dirs:
         rels_dir = unpacked_dir / "ppt" / dir_name / "_rels"
@@ -137,35 +169,15 @@ def remove_orphaned_rels_files(unpacked_dir: Path) -> list[str]:
 
         for rels_file in rels_dir.glob("*.rels"):
             resource_file = rels_dir.parent / rels_file.name.replace(".rels", "")
-            try:
-                resource_rel_path = resource_file.resolve().relative_to(unpacked_dir.resolve())
-            except ValueError:
-                continue
-
-            if not resource_file.exists() or resource_rel_path not in slide_referenced:
+            if not resource_file.exists():
                 rels_file.unlink()
-                rel_path = rels_file.relative_to(unpacked_dir)
-                removed.append(str(rel_path))
+                removed.append(str(rels_file.relative_to(unpacked_dir)))
 
     return removed
 
 
 def get_referenced_files(unpacked_dir: Path) -> set:
-    referenced = set()
-
-    for rels_file in unpacked_dir.rglob("*.rels"):
-        dom = defusedxml.minidom.parse(str(rels_file))
-        for rel in dom.getElementsByTagName("Relationship"):
-            target = rel.getAttribute("Target")
-            if not target:
-                continue
-            target_path = (rels_file.parent.parent / target).resolve()
-            try:
-                referenced.add(target_path.relative_to(unpacked_dir.resolve()))
-            except ValueError:
-                pass
-
-    return referenced
+    return _referenced_by(sorted(unpacked_dir.rglob("*.rels")), unpacked_dir)
 
 
 def remove_orphaned_files(unpacked_dir: Path, referenced: set) -> list[str]:
@@ -241,6 +253,12 @@ def update_content_types(unpacked_dir: Path, removed_files: list[str]) -> None:
 def clean_unused_files(unpacked_dir: Path) -> list[str]:
     all_removed = []
 
+    if list(unpacked_dir.rglob("*.rels")) and not get_referenced_files(unpacked_dir):
+        raise RefusedToClean(
+            "no relationship in this package names a part we can resolve. "
+            "Refusing to treat every file as unreferenced."
+        )
+
     slides_removed = remove_orphaned_slides(unpacked_dir)
     all_removed.extend(slides_removed)
 
@@ -276,7 +294,12 @@ if __name__ == "__main__":
         print(f"Error: {unpacked_dir} not found", file=sys.stderr)
         sys.exit(1)
 
-    removed = clean_unused_files(unpacked_dir)
+    try:
+        removed = clean_unused_files(unpacked_dir)
+    except (RefusedToClean, ValueError) as e:
+        print(f"Error: {e}", file=sys.stderr)
+        print("Nothing was deleted.", file=sys.stderr)
+        sys.exit(1)
 
     if removed:
         print(f"Removed {len(removed)} unreferenced files:")