From e4e99d198b5461ed43c97934832a035672956686 Mon Sep 17 00:00:00 2001
From: CYJ1226 <68060964+CYJ1226@users.noreply.github.com>
Date: Mon, 27 Jul 2026 12:21:26 +0900
Subject: [PATCH] fix: preserve spaces during recursive text splitting (#39498)

---
 api/core/rag/splitter/fixed_text_splitter.py      |  4 ++--
 .../core/rag/splitter/test_text_splitter.py       | 15 +++++++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/api/core/rag/splitter/fixed_text_splitter.py b/api/core/rag/splitter/fixed_text_splitter.py
index 98ba4d7fcc7..687f544e874 100644
--- a/api/core/rag/splitter/fixed_text_splitter.py
+++ b/api/core/rag/splitter/fixed_text_splitter.py
@@ -91,8 +91,8 @@ class FixedRecursiveCharacterTextSplitter(EnhanceRecursiveCharacterTextSplitter)
                 splits = re.split(r" +", text)
             else:
                 splits = text.split(separator)
-                if self._keep_separator:
-                    splits = [s + separator for s in splits[:-1]] + splits[-1:]
+            if self._keep_separator:
+                splits = [s + separator for s in splits[:-1]] + splits[-1:]
         else:
             splits = list(text)
         if separator == "\n":
diff --git a/api/tests/unit_tests/core/rag/splitter/test_text_splitter.py b/api/tests/unit_tests/core/rag/splitter/test_text_splitter.py
index 12117241b5d..7a0726d3a9c 100644
--- a/api/tests/unit_tests/core/rag/splitter/test_text_splitter.py
+++ b/api/tests/unit_tests/core/rag/splitter/test_text_splitter.py
@@ -952,6 +952,21 @@ class TestFixedRecursiveCharacterTextSplitter:
         assert "word1" in combined
         assert "word2" in combined
 
+    def test_preserves_spaces_when_recursively_splitting_long_paragraph(self):
+        """Ensure recursive space splitting preserves word boundaries."""
+        text = "여름철에는 항상 기상상황에 주목하며 주변 사람들과 함께 정보를 공유합니다."
+        splitter = FixedRecursiveCharacterTextSplitter(
+            fixed_separator="\n\n",
+            chunk_size=20,
+            chunk_overlap=0,
+            keep_separator=True,
+        )
+
+        result = splitter.split_text(text)
+
+        assert len(result) > 1
+        assert " ".join(result) == text
+
     def test_character_level_splitting(self):
         """Test character-level splitting when no separator works."""
         text = "verylongwordwithoutspaces"