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BUG: Cope with indirect objects in filters and remove deprecated code (…
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…#2177)

closes #2158
closes #2159
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@pubpub-zz
pubpub-zz authored Sep 10, 2023
1 parent f68138c commit 0ca4d37
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Showing 2 changed files with 46 additions and 54 deletions.
91 changes: 42 additions & 49 deletions pypdf/filters.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -43,6 +43,7 @@
from ._utils import (
b_,
deprecate_with_replacement,
deprecation_no_replacement,
logger_warning,
ord_,
)
Expand All @@ -53,7 +54,7 @@
from .constants import ImageAttributes as IA
from .constants import LzwFilterParameters as LZW
from .constants import StreamAttributes as SA
from .errors import PdfReadError, PdfStreamError
from .errors import DeprecationError, PdfReadError, PdfStreamError
from .generic import (
ArrayObject,
DictionaryObject,
Expand Down Expand Up @@ -93,7 +94,7 @@ class FlateDecode:
@staticmethod
def decode(
data: bytes,
decode_parms: Union[None, ArrayObject, DictionaryObject] = None,
decode_parms: Optional[DictionaryObject] = None,
**kwargs: Any,
) -> bytes:
"""
Expand All @@ -113,42 +114,37 @@ def decode(
if "decodeParms" in kwargs: # deprecated
deprecate_with_replacement("decodeParms", "parameters", "4.0.0")
decode_parms = kwargs["decodeParms"]
if isinstance(decode_parms, ArrayObject): # type: ignore
raise DeprecationError("decode_parms as ArrayObject is depreciated")

str_data = decompress(data)
predictor = 1

if decode_parms:
try:
if isinstance(decode_parms, ArrayObject):
for decode_parm in decode_parms:
if "/Predictor" in decode_parm:
predictor = decode_parm["/Predictor"]
else:
predictor = decode_parms.get("/Predictor", 1)
predictor = decode_parms.get("/Predictor", 1)
except (AttributeError, TypeError): # Type Error is NullObject
pass # Usually an array with a null object was read
# predictor 1 == no predictor
if predictor != 1:
# The /Columns param. has 1 as the default value; see ISO 32000,
# §7.4.4.3 LZWDecode and FlateDecode Parameters, Table 8
DEFAULT_BITS_PER_COMPONENT = 8
if isinstance(decode_parms, ArrayObject):
try:
columns = cast(int, decode_parms[LZW.COLUMNS].get_object()) # type: ignore
except (TypeError, KeyError):
columns = 1
bits_per_component = DEFAULT_BITS_PER_COMPONENT
for decode_parm in decode_parms:
if "/Columns" in decode_parm:
columns = decode_parm["/Columns"]
if LZW.BITS_PER_COMPONENT in decode_parm:
bits_per_component = decode_parm[LZW.BITS_PER_COMPONENT]
else:
columns = (
1 if decode_parms is None else decode_parms.get(LZW.COLUMNS, 1)
)
colors = 1 if decode_parms is None else decode_parms.get(LZW.COLORS, 1)
bits_per_component = (
decode_parms.get(LZW.BITS_PER_COMPONENT, DEFAULT_BITS_PER_COMPONENT)
if decode_parms
else DEFAULT_BITS_PER_COMPONENT
try:
colors = cast(int, decode_parms[LZW.COLORS].get_object()) # type: ignore
except (TypeError, KeyError):
colors = 1
try:
bits_per_component = cast(
int,
decode_parms[LZW.BITS_PER_COMPONENT].get_object(), # type: ignore
)
except (TypeError, KeyError):
bits_per_component = DEFAULT_BITS_PER_COMPONENT

# PNG predictor can vary by row and so is the lead byte on each row
rowlength = (
Expand Down Expand Up @@ -259,7 +255,7 @@ class ASCIIHexDecode:
@staticmethod
def decode(
data: Union[str, bytes],
decode_parms: Union[None, ArrayObject, DictionaryObject] = None,
decode_parms: Optional[DictionaryObject] = None,
**kwargs: Any,
) -> bytes:
"""
Expand All @@ -278,9 +274,8 @@ def decode(
Raises:
PdfStreamError:
"""
if "decodeParms" in kwargs: # deprecated
deprecate_with_replacement("decodeParms", "parameters", "4.0.0")
decode_parms = kwargs["decodeParms"] # noqa: F841
# decode_parms is unused here

if isinstance(data, str):
data = data.encode()
retval = b""
Expand Down Expand Up @@ -321,7 +316,7 @@ class RunLengthDecode:
@staticmethod
def decode(
data: bytes,
decode_parms: Union[None, ArrayObject, DictionaryObject] = None,
decode_parms: Optional[DictionaryObject] = None,
**kwargs: Any,
) -> bytes:
"""
Expand All @@ -337,9 +332,8 @@ def decode(
Raises:
PdfStreamError:
"""
if "decodeParms" in kwargs: # deprecated
deprecate_with_replacement("decodeParms", "parameters", "4.0.0")
decode_parms = kwargs["decodeParms"] # noqa: F841
# decode_parms is unused here

lst = []
index = 0
while True:
Expand Down Expand Up @@ -453,7 +447,7 @@ def decode(self) -> str:
@staticmethod
def decode(
data: bytes,
decode_parms: Union[None, ArrayObject, DictionaryObject] = None,
decode_parms: Optional[DictionaryObject] = None,
**kwargs: Any,
) -> str:
"""
Expand All @@ -466,9 +460,8 @@ def decode(
Returns:
decoded data.
"""
if "decodeParms" in kwargs: # deprecated
deprecate_with_replacement("decodeParms", "parameters", "4.0.0")
decode_parms = kwargs["decodeParms"] # noqa: F841
# decode_parms is unused here

return LZWDecode.Decoder(data).decode()


Expand All @@ -478,12 +471,11 @@ class ASCII85Decode:
@staticmethod
def decode(
data: Union[str, bytes],
decode_parms: Union[None, ArrayObject, DictionaryObject] = None,
decode_parms: Optional[DictionaryObject] = None,
**kwargs: Any,
) -> bytes:
if "decodeParms" in kwargs: # deprecated
deprecate_with_replacement("decodeParms", "parameters", "4.0.0")
decode_parms = kwargs["decodeParms"] # noqa: F841
# decode_parms is unused here

if isinstance(data, str):
data = data.encode("ascii")
group_index = b = 0
Expand Down Expand Up @@ -511,25 +503,21 @@ class DCTDecode:
@staticmethod
def decode(
data: bytes,
decode_parms: Union[None, ArrayObject, DictionaryObject] = None,
decode_parms: Optional[DictionaryObject] = None,
**kwargs: Any,
) -> bytes:
if "decodeParms" in kwargs: # deprecated
deprecate_with_replacement("decodeParms", "parameters", "4.0.0")
decode_parms = kwargs["decodeParms"] # noqa: F841
# decode_parms is unused here
return data


class JPXDecode:
@staticmethod
def decode(
data: bytes,
decode_parms: Union[None, ArrayObject, DictionaryObject] = None,
decode_parms: Optional[DictionaryObject] = None,
**kwargs: Any,
) -> bytes:
if "decodeParms" in kwargs: # deprecated
deprecate_with_replacement("decodeParms", "parameters", "4.0.0")
decode_parms = kwargs["decodeParms"] # noqa: F841
# decode_parms is unused here
return data


Expand Down Expand Up @@ -591,13 +579,18 @@ def _get_parameters(
@staticmethod
def decode(
data: bytes,
decode_parms: Union[None, ArrayObject, DictionaryObject] = None,
decode_parms: Optional[DictionaryObject] = None,
height: int = 0,
**kwargs: Any,
) -> bytes:
# decode_parms is unused here
if "decodeParms" in kwargs: # deprecated
deprecate_with_replacement("decodeParms", "parameters", "4.0.0")
decode_parms = kwargs["decodeParms"]
if isinstance(decode_parms, ArrayObject): # deprecated
deprecation_no_replacement(
"decode_parms being an ArrayObject", removed_in="3.15.5"
)
parms = CCITTFaxDecode._get_parameters(decode_parms, height)

img_size = len(data)
Expand Down
9 changes: 4 additions & 5 deletions tests/test_filters.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@
from PIL import Image

from pypdf import PdfReader
from pypdf.errors import PdfReadError, PdfStreamError
from pypdf.errors import DeprecationError, PdfReadError, PdfStreamError
from pypdf.filters import (
ASCII85Decode,
ASCIIHexDecode,
Expand Down Expand Up @@ -69,16 +69,15 @@ def test_flatedecode_unsupported_predictor():
codec.decode(codec.encode(s), DictionaryObject({"/Predictor": predictor}))


@pytest.mark.parametrize(
"params", [ArrayObject([]), ArrayObject([{"/Predictor": 1}]), "a"]
)
@pytest.mark.parametrize("params", [ArrayObject([]), ArrayObject([{"/Predictor": 1}])])
def test_flate_decode_decompress_with_array_params(params):
"""FlateDecode decode() method works correctly with array parameters."""
codec = FlateDecode()
s = ""
s = s.encode()
encoded = codec.encode(s)
assert codec.decode(encoded, params) == s
with pytest.raises(DeprecationError):
assert codec.decode(encoded, params) == s


@pytest.mark.parametrize(
Expand Down

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