tpl.get_undeclared_variables() resets rendered template

[Slarag]

Describe the bug

A call to tpl.get_undeclared_variables() resets document rendering and returns all variables defined in the template. This conflicts with the documentation

To Reproduce

Run the code below on any template with some jinja variables.

import os.path
from docxtpl import DocxTemplate

doctemplate = r'test.docx'

if __name__ == '__main__':
    doc = DocxTemplate(os.path.abspath(doctemplate))
    context = {
        'test': 'HelloWorld'
    }
    doc.render(context)

    # Without the line below, rendering works fine. With this line, the rendering will be reset
    print(doc.get_undeclared_template_variables())

    doc.save("output.docx")

Expected behavior

tpl.get_undeclared_variables() must not reset the rendered template.

Screenshots

If applicable, add screenshots to help explain your problem.

Additional context

To fix this issue, change line 47 of template.py from if not self.docx or self.is_rendered: to if not self.docx or not self.is_rendered:

test.docx

[Slarag]

Issue was introduced with commit 23038b98de1f5d8cc710145ceda596a61816583a

[elapouya]

fixed in v0.16.5