ROB: warn-only in readStringFromStream (#837)

An unexpected escape string was raising a PdfReadError before.
Now, only a warning is issued.

Closes #360
Closes #794 : Passing the strict parameter looks like a good idea,
              but there is also the pdf parameter. Sadly, it is
              None for that issue.

PyPDF2/generic.py

@@ -422,9 +422,9 @@ def readStringFromStream(stream):
                     # line break was escaped:
                     tok = b_("")
                 else:
-                    raise PdfReadError(
-                        r"Unexpected escaped string: {}".format(tok.decode("utf8"))
-                    )
+                    msg = r"Unexpected escaped string: {}".format(tok.decode("utf8"))
+                    # if.strict: PdfReadError(msg)
+                    logger.warning(msg)
         txt += tok
     return createStringObject(txt)
 

Tests/test_generic.py

@@ -113,7 +113,8 @@ def test_readStringFromStream_not_in_escapedict_no_digit():
     stream = BytesIO(b"x\\y")
     with pytest.raises(PdfReadError) as exc:
         readStringFromStream(stream)
-    assert exc.value.args[0] == "Unexpected escaped string: y"
+    assert exc.value.args[0] == "Stream has ended unexpectedly"
+    # "Unexpected escaped string: y"
 
 
 def test_readStringFromStream_multichar_eol():
@@ -216,6 +217,11 @@ def test_DictionaryObject_key_is_no_pdfobject():
     assert exc.value.args[0] == "key must be PdfObject"
 
 
+def test_DictionaryObject_xmp_meta():
+    do = DictionaryObject({NameObject("/S"): NameObject("/GoTo")})
+    assert do.xmpMetadata is None
+
+
 def test_DictionaryObject_value_is_no_pdfobject():
     do = DictionaryObject({NameObject("/S"): NameObject("/GoTo")})
     with pytest.raises(ValueError) as exc:
@@ -237,6 +243,11 @@ def test_DictionaryObject_setdefault_value_is_no_pdfobject():
     assert exc.value.args[0] == "value must be PdfObject"
 
 
+def test_DictionaryObject_setdefault_value():
+    do = DictionaryObject({NameObject("/S"): NameObject("/GoTo")})
+    do.setdefault(NameObject("/S"), NameObject("/GoTo"))
+
+
 def test_DictionaryObject_read_from_stream():
     stream = BytesIO(b"<< /S /GoTo >>")
     pdf = None