From ce39e2e22bbdc4f403fbc77b95cecca0250974f9 Mon Sep 17 00:00:00 2001
From: Saki Takamachi <saki@php.net>
Date: Mon, 21 Apr 2025 09:16:40 +0900
Subject: [PATCH 1/2] Added a test

---
 ext/standard/tests/file/gh18348.phpt | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 ext/standard/tests/file/gh18348.phpt

diff --git a/ext/standard/tests/file/gh18348.phpt b/ext/standard/tests/file/gh18348.phpt
new file mode 100644
index 0000000000000..2a75b265372b5
--- /dev/null
+++ b/ext/standard/tests/file/gh18348.phpt
@@ -0,0 +1,18 @@
+--TEST--
+GH-18348 (fputcsv incorrectly escapes when quote char is both enclosure and escape char)
+--FILE--
+<?php
+
+$fp = fopen ('php://temp', 'r+');
+
+fputcsv($fp, ['J"a"n'], ',', '"', 'a');
+fputcsv($fp, ['He said "Hello"'], ',', '"', '"');
+fputcsv($fp, ['Line1\\Line2'], ',', '"', '\\');
+
+rewind($fp);
+echo stream_get_contents($fp);
+?>
+--EXPECT--
+"J""a""n"
+"He said ""Hello"""
+"Line1\Line2"

From 5b65e2c313744f03c92ed6ca05444e9e6a0087cf Mon Sep 17 00:00:00 2001
From: Saki Takamachi <saki@php.net>
Date: Mon, 21 Apr 2025 09:20:18 +0900
Subject: [PATCH 2/2] Removed the conditional branch for escape_char.

---
 ext/standard/file.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/ext/standard/file.c b/ext/standard/file.c
index 5936766dac863..c42b92e0ebe1a 100644
--- a/ext/standard/file.c
+++ b/ext/standard/file.c
@@ -1788,16 +1788,11 @@ PHPAPI ssize_t php_fputcsv(php_stream *stream, zval *fields, char delimiter, cha
 		) {
 			char *ch = ZSTR_VAL(field_str);
 			char *end = ch + ZSTR_LEN(field_str);
-			int escaped = 0;
 
 			smart_str_appendc(&csvline, enclosure);
 			while (ch < end) {
-				if (escape_char != PHP_CSV_NO_ESCAPE && *ch == escape_char) {
-					escaped = 1;
-				} else if (!escaped && *ch == enclosure) {
+				if (*ch == enclosure) {
 					smart_str_appendc(&csvline, enclosure);
-				} else {
-					escaped = 0;
 				}
 				smart_str_appendc(&csvline, *ch);
 				ch++;