From c045c6f6bf2db9f5b8bf2b2e5388a5229d4762a7 Mon Sep 17 00:00:00 2001
From: pubpub-zz <4083478+pubpub-zz@users.noreply.github.com>
Date: Sun, 26 May 2024 10:51:21 +0200
Subject: [PATCH] ROB: cope with missing Standard 14 fonts in fields

closes #2670
---
 pypdf/_writer.py     |  5 +++--
 tests/test_writer.py | 16 ++++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/pypdf/_writer.py b/pypdf/_writer.py
index b8e6c1f20..6b6d55a6e 100644
--- a/pypdf/_writer.py
+++ b/pypdf/_writer.py
@@ -53,7 +53,7 @@
     cast,
 )
 
-from ._cmap import build_char_map_from_dict
+from ._cmap import _default_fonts_space_width, build_char_map_from_dict
 from ._doc_common import PdfDocCommon
 from ._encryption import EncryptAlgorithm, Encryption
 from ._page import PageObject
@@ -835,7 +835,8 @@ def _update_field_annotation(
             ).get_object(),
         )
         dr = dr.get("/Font", DictionaryObject()).get_object()
-        if font_name not in dr:
+        # _default_fonts_space_width keys is the list of Standard fonts
+        if font_name not in dr and font_name not in _default_fonts_space_width:
             # ...or AcroForm dictionary
             dr = cast(
                 Dict[Any, Any],
diff --git a/tests/test_writer.py b/tests/test_writer.py
index 7a1bad60f..b026770be 100644
--- a/tests/test_writer.py
+++ b/tests/test_writer.py
@@ -2253,3 +2253,19 @@ def test_selfont():
     assert (
         b"Text_2" in writer.pages[0]["/Annots"][2].get_object()["/AP"]["/N"].get_data()
     )
+
+
+@pytest.mark.enable_socket()
+def test_no_ressource_for_14_std_fonts(caplog):
+    """Cf #2670"""
+    url = "https://github.com/py-pdf/pypdf/files/15405390/f1040.pdf"
+    name = "iss2670.pdf"
+    writer = PdfWriter(BytesIO(get_data_from_url(url, name=name)))
+    p = writer.pages[0]
+    for a in p["/Annots"]:
+        a = a.get_object()
+        if a["/FT"] == "/Tx":
+            writer.update_page_form_field_values(
+                p, {a["/T"]: "Brooks"}, auto_regenerate=False
+            )
+    assert "Font dictionary for /Helvetica not found." in caplog.text