ROB: Accept '/annn' charset as ASCII code (#1316)

Closes #1312

Author: pubpub-zz

PyPDF2/_codecs/adobe_glyphs.py

@@ -13425,3 +13425,13 @@
     "/zukatakana": "\u30BA",
     "/zwarakay": "\u0659",
 }
+
+
+def _complete() -> None:
+    global adobe_glyphs
+    for i in range(256):
+        adobe_glyphs[f"/a{i}"] = chr(i)
+    adobe_glyphs["/.notdef"] = "□"
+
+
+_complete()

tests/test_cmap.py

@@ -46,3 +46,11 @@ def test_get_font_width_from_default():  # L40
     reader = PdfReader(BytesIO(get_pdf_from_url(url, name=name)))
     for page in reader.pages:
         page.extract_text()
+
+
+def test_ascii_charset():
+    # iss #1312
+    url = "https://github.com/py-pdf/PyPDF2/files/9472500/main.pdf"
+    name = "ascii charset.pdf"
+    reader = PdfReader(BytesIO(get_pdf_from_url(url, name=name)))
+    assert "/a" not in reader.pages[0].extract_text()