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From: "Miss Islington (bot)"
 <31488909+miss-islington@users.noreply.github.com>
Date: Wed, 29 Jan 2025 12:32:54 +0100
Subject: [PATCH] [3.12] gh-129409: Fix Integer overflow -  SEGV while writing
 data more than 2GB in CSV file (GH-129413) (#129437)
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gh-129409: Fix Integer overflow -  SEGV while writing data more than 2GB in CSV file (GH-129413)
(cherry picked from commit 97b0ef05d987ebef354512b516a246feb411e815)

Co-authored-by: Srinivas Reddy Thatiparthy (తాటిపర్తి శ్రీనివాస్  రెడ్డి) <thatiparthysreenivas@gmail.com>
---
 .../next/Library/2025-01-29-14-30-54.gh-issue-129409.JZbOE6.rst | 2 ++
 Modules/_csv.c                                                  | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)
 create mode 100644 Misc/NEWS.d/next/Library/2025-01-29-14-30-54.gh-issue-129409.JZbOE6.rst

diff --git a/Misc/NEWS.d/next/Library/2025-01-29-14-30-54.gh-issue-129409.JZbOE6.rst b/Misc/NEWS.d/next/Library/2025-01-29-14-30-54.gh-issue-129409.JZbOE6.rst
new file mode 100644
index 00000000000000..7e00b44c0ef471
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-01-29-14-30-54.gh-issue-129409.JZbOE6.rst
@@ -0,0 +1,2 @@
+Fix an integer overflow in the :mod:`csv` module when writing a data field
+larger than 2GB.
diff --git a/Modules/_csv.c b/Modules/_csv.c
index 9a7b7d27c2ed39..df7207d0894af8 100644
--- a/Modules/_csv.c
+++ b/Modules/_csv.c
@@ -1074,7 +1074,7 @@ join_append_data(WriterObj *self, int field_kind, const void *field_data,
                  int copy_phase)
 {
     DialectObj *dialect = self->dialect;
-    int i;
+    Py_ssize_t i;
     Py_ssize_t rec_len;
 
 #define INCLEN \