ENH: Make PdfReader.get_object accept integer arguments (#1459)

Also fix various type annotations

PyPDF2/_reader.py

@@ -863,14 +863,18 @@ def getDestinationPageNumber(
     def _build_destination(
         self,
         title: str,
-        array: List[Union[NumberObject, IndirectObject, NullObject, DictionaryObject]],
+        array: Optional[
+            List[
+                Union[NumberObject, IndirectObject, None, NullObject, DictionaryObject]
+            ]
+        ],
     ) -> Destination:
         page, typ = None, None
         # handle outline items with missing or invalid destination
         if (
-            isinstance(array, (type(None), NullObject))
+            isinstance(array, (NullObject, str))
             or (isinstance(array, ArrayObject) and len(array) == 0)
-            or (isinstance(array, str))
+            or array is None
         ):
 
             page = NullObject()
@@ -898,7 +902,7 @@ def _build_outline_item(self, node: DictionaryObject) -> Optional[Destination]:
         # title required for valid outline
         # PDF Reference 1.7: TABLE 8.4 Entries in an outline item dictionary
         try:
-            title = node["/Title"]
+            title = cast("str", node["/Title"])
         except KeyError:
             if self.strict:
                 raise PdfReadError(f"Outline Entry Missing /Title attribute: {node!r}")
@@ -918,23 +922,29 @@ def _build_outline_item(self, node: DictionaryObject) -> Optional[Destination]:
                 dest = dest["/D"]
 
         if isinstance(dest, ArrayObject):
-            outline_item = self._build_destination(title, dest)  # type: ignore
+            outline_item = self._build_destination(title, dest)
         elif isinstance(dest, str):
             # named destination, addresses NameObject Issue #193
+            # TODO : keep named destination instead of replacing it ?
             try:
                 outline_item = self._build_destination(
                     title, self._namedDests[dest].dest_array
                 )
             except KeyError:
                 # named destination not found in Name Dict
                 outline_item = self._build_destination(title, None)
-        elif isinstance(dest, type(None)):
+        elif dest is None:
             # outline item not required to have destination or action
             # PDFv1.7 Table 153
-            outline_item = self._build_destination(title, dest)  # type: ignore
+            outline_item = self._build_destination(title, dest)
         else:
             if self.strict:
                 raise PdfReadError(f"Unexpected destination {dest!r}")
+            else:
+                logger_warning(
+                    f"Removed unexpected destination {dest!r} from destination",
+                    __name__,
+                )
             outline_item = self._build_destination(title, None)  # type: ignore
 
         # if outline item created, add color, format, and child count if present
@@ -950,7 +960,6 @@ def _build_outline_item(self, node: DictionaryObject) -> Optional[Destination]:
                 # absolute value = num. visible children
                 # positive = open/unfolded, negative = closed/folded
                 outline_item[NameObject("/Count")] = node["/Count"]
-
         return outline_item
 
     @property
@@ -1154,7 +1163,18 @@ def _get_object_from_stream(
             raise PdfReadError("This is a fatal error in strict mode.")
         return NullObject()
 
-    def get_object(self, indirect_reference: IndirectObject) -> Optional[PdfObject]:
+    def _get_indirect_object(self, num: int, gen: int) -> Optional[PdfObject]:
+        """
+        used to ease development
+        equivalent to generic.IndirectObject(num,gen,self).get_object()
+        """
+        return IndirectObject(num, gen, self).get_object()
+
+    def get_object(
+        self, indirect_reference: Union[int, IndirectObject]
+    ) -> Optional[PdfObject]:
+        if isinstance(indirect_reference, int):
+            indirect_reference = IndirectObject(indirect_reference, 0, self)
         retval = self.cache_get_indirect_object(
             indirect_reference.generation, indirect_reference.idnum
         )
@@ -1928,13 +1948,6 @@ def xfa(self) -> Optional[Dict[str, Any]]:
                         retval[tag] = es
         return retval
 
-    def _get_indirect_object(self, num: int, gen: int) -> Optional[PdfObject]:
-        """
-        used to ease development
-        equivalent to generic.IndirectObject(num,gen,self).get_object()
-        """
-        return IndirectObject(num, gen, self).get_object()
-
 
 class PdfFileReader(PdfReader):  # pragma: no cover
     def __init__(self, *args: Any, **kwargs: Any) -> None:

tests/test_reader.py

@@ -17,7 +17,13 @@
     PdfReadWarning,
     WrongPasswordError,
 )
-from PyPDF2.generic import Destination
+from PyPDF2.generic import (
+    Destination,
+    DictionaryObject,
+    NameObject,
+    NumberObject,
+    TextStringObject,
+)
 
 from . import get_pdf_from_url, normalize_warnings
 
@@ -755,6 +761,12 @@ def test_iss925():
                 annot.get_object()
 
 
+def test_get_object():
+    reader = PdfReader(RESOURCE_ROOT / "hello-world.pdf")
+    assert reader.get_object(22)["/Type"] == "/Catalog"
+    assert reader._get_indirect_object(22, 0)["/Type"] == "/Catalog"
+
+
 @pytest.mark.xfail(reason="#591")
 def test_extract_text_hello_world():
     reader = PdfReader(RESOURCE_ROOT / "hello-world.pdf")
@@ -1179,3 +1191,30 @@ def test_zeroing_xref():
     name = "UTA_OSHA.pdf"
     reader = PdfReader(BytesIO(get_pdf_from_url(url, name=name)))
     len(reader.pages)
+
+
+def test_build_outline_item(caplog):
+    url = "https://github.com/py-pdf/PyPDF2/files/9464742/shiv_resume.pdf"
+    name = "shiv_resume.pdf"
+    reader = PdfReader(BytesIO(get_pdf_from_url(url, name=name)))
+    outline = reader._build_outline_item(
+        DictionaryObject(
+            {
+                NameObject("/Title"): TextStringObject("Toto"),
+                NameObject("/Dest"): NumberObject(2),
+            }
+        )
+    )
+    assert "Removed unexpected destination 2 from destination" in caplog.text
+    assert outline["/Title"] == "Toto"
+    reader.strict = True
+    with pytest.raises(PdfReadError) as exc:
+        reader._build_outline_item(
+            DictionaryObject(
+                {
+                    NameObject("/Title"): TextStringObject("Toto"),
+                    NameObject("/Dest"): NumberObject(2),
+                }
+            )
+        )
+    assert "Unexpected destination 2" in exc.value.args[0]

tests/test_writer.py

@@ -343,6 +343,7 @@ def test_write_metadata():
     reader = PdfReader(pdf_path)
     writer = PdfWriter()
 
+    writer.add_page(reader.pages[0])
     for page in reader.pages:
         writer.add_page(page)