[Bug]: Extra newline at end of output with Jinja template

What happened?

Even with trim_blocks=True and lstrip_blocks=True, a template like this will result in not one, but two newlines at the end of the generated output:

{% for line in lines %}
{{ line }}
{% endfor %}

With lines = ['a', 'b', 'c'], this will generate:

a\n
b\n
c\n
\n

I'd expect the output to end with a single newline instead of two.

If there is content after {% endfor %}, no additional newline will be generated, so this template:

{% for line in lines %}
{{ line }}
{% endfor %}
x

will generate this output, which is what I'd expect:

a\n
b\n
c\n
x\n

Type of salt install

Official rpm

Major version

3007.x

What supported OS are you seeing the problem on? Can select multiple. (If bug appears on an unsupported OS, please open a GitHub Discussion instead)

rhel-10

salt --versions-report output

Salt Version:
          Salt: 3008.2
 
Python Version:
        Python: 3.14.6 (main, Jun 11 2026, 02:19:05) [GCC 11.2.0]
 
Dependency Versions:
          cffi: 2.0.0
      cherrypy: 18.10.0
  cryptography: 48.0.0
      dateutil: 2.9.0.post0
     docker-py: Not Installed
         gitdb: 4.0.12
     gitpython: 3.1.50
        Jinja2: 3.1.6
       libgit2: Not Installed
  looseversion: 1.3.0
      M2Crypto: Not Installed
          Mako: Not Installed
       msgpack: 1.1.2
  msgpack-pure: Not Installed
  mysql-python: Not Installed
     packaging: 24.0
     pycparser: 3.00
      pycrypto: Not Installed
  pycryptodome: 3.23.0
        pygit2: Not Installed
  python-gnupg: 0.5.6
        PyYAML: 6.0.3
         PyZMQ: 27.1.0
        relenv: 0.22.14
         smmap: 5.0.2
       timelib: 0.3.0
       Tornado: 6.5.7
           ZMQ: 4.3.5
 
Salt Package Information:
  Package Type: onedir
 
System Versions:
          dist: rhel 10.2 Coughlan
        locale: utf-8
       machine: x86_64
       release: 6.12.0-211.30.1.el10_2.x86_64
        system: Linux
       version: Red Hat Enterprise Linux 10.2 Coughlan

Start by reproducing the reported Jinja template with trim_blocks=True and lstrip_blocks=True in Salt's rendering path. Trace how the template output is assembled, add a regression test for a single trailing newline, and verify that content after the loop remains unchanged.