From 82cdca07232178734b094a9a50d637fbe5aadfae Mon Sep 17 00:00:00 2001
From: rdl <rdl@provexi.fr>
Date: Thu, 26 Oct 2023 09:15:51 +0200
Subject: [PATCH] Add suggestion from pubpub-zz

---
 pypdf/_writer.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pypdf/_writer.py b/pypdf/_writer.py
index 64cd9eb89..8f4767415 100644
--- a/pypdf/_writer.py
+++ b/pypdf/_writer.py
@@ -920,8 +920,8 @@ def _update_text_field(self, field: DictionaryObject) -> None:
         else:  # /Tx
             txt = field.get("/V", "")
             sel = []
-        # Escape parentheses (Ref. 7.3.4.2 Literal Strings)
-        txt = txt.replace('(', r'\(').replace(')', r'\)')
+        # Escape parentheses (pdf 1.7 reference, table 3.2  Literal Strings)
+        txt = txt.replace("\\", "\\\\").replace("(", r"\(").replace(")", r"\)")
         # Generate appearance stream
         ap_stream = f"q\n/Tx BMC \nq\n1 1 {rct.width - 1} {rct.height - 1} re\nW\nBT\n{da}\n".encode()
         for line_number, line in enumerate(txt.replace("\n", "\r").split("\r")):