From a15b318bea0951d1b47758c222c81e69e134a261 Mon Sep 17 00:00:00 2001
From: wayyoungboy <1017761807@qq.com>
Date: Sun, 7 Jun 2026 05:54:31 +0800
Subject: [PATCH] Fix indent filter for empty first line

---
 src/jinja2/filters.py | 3 ++-
 tests/test_filters.py | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/jinja2/filters.py b/src/jinja2/filters.py
index c46e20c10..394fb4ab3 100644
--- a/src/jinja2/filters.py
+++ b/src/jinja2/filters.py
@@ -847,6 +847,7 @@ def do_indent(
         indention = Markup(indention)
         newline = Markup(newline)
 
+    is_empty = not s
     s += newline  # this quirk is necessary for splitlines method
 
     if blank:
@@ -860,7 +861,7 @@ def do_indent(
                 indention + line if line else line for line in lines
             )
 
-    if first:
+    if first and (not is_empty or blank):
         rv = indention + rv
 
     return rv
diff --git a/tests/test_filters.py b/tests/test_filters.py
index 4601469a6..dd37df763 100644
--- a/tests/test_filters.py
+++ b/tests/test_filters.py
@@ -179,6 +179,10 @@ def test_indent(self, env):
         t = env.from_string('{{ "jinja"|indent(blank=true) }}')
         assert t.render() == "jinja"
 
+    def test_indent_empty_string_with_first(self, env):
+        t = env.from_string('{{ ""|indent(first=true) }}')
+        assert t.render() == ""
+
     def test_indent_markup_input(self, env):
         """
         Tests cases where the filter input is a Markup type