TST: Ignore Producer key mismatches in PGF metadata.

QuLogic · QuLogic · commit ea09d95626d2 · 2021-05-04T19:37:10.000-04:00
Some LaTeX engines ignore the setting of this key in hyperref, but
otherwise obey the request metadata. This is likely still okay, but
leave a note in the docs as well.
diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
@@ -948,6 +948,9 @@ def __init__(self, filename, *, keep_empty=True, metadata=None):
             'Creator', 'Producer', 'CreationDate', 'ModDate', and
             'Trapped'. Values have been predefined for 'Creator', 'Producer'
             and 'CreationDate'. They can be removed by setting them to `None`.
+
+            Note that some versions of LaTeX engines may ignore the 'Producer'
+            key and set it to themselves.
         """
         self._output_name = filename
         self._n_figures = 0
diff --git a/lib/matplotlib/tests/test_backend_pgf.py b/lib/matplotlib/tests/test_backend_pgf.py
@@ -257,13 +257,17 @@ def test_pdf_pages_metadata_check(monkeypatch, system):
     if '/PTEX.Fullbanner' in info:
         del info['/PTEX.Fullbanner']
 
+    # Some LaTeX engines ignore this setting, and state themselves as producer.
+    producer = info.pop('/Producer')
+    assert producer == f'Matplotlib pgf backend v{mpl.__version__}' or (
+            system == 'lualatex' and 'LuaTeX' in producer)
+
     assert info == {
         '/Author': 'me',
         '/CreationDate': 'D:19700101000000Z',
         '/Creator': f'Matplotlib v{mpl.__version__}, https://matplotlib.org',
         '/Keywords': 'test,pdf,multipage',
         '/ModDate': 'D:19680801000000Z',
-        '/Producer': f'Matplotlib pgf backend v{mpl.__version__}',
         '/Subject': 'Test page',
         '/Title': 'Multipage PDF with pgf',
         '/Trapped': '/True',
