[FIX] core: PyPDF2 suppresses warnings

By default, PdfFileReader will monkeypatch the `warnings` module even
if it has no reason whatsoever to do so and suppress the
`captureWarnings` behavior.

This means as soon as we've loaded a PDF file, `warnings.warn` don't
trigger `logging` warnings anymore, and become invisible.

This can lead to non-deterministic behaviors depending as warnings may
or may not be suppressed depending when they occur relative to loading
a PDF e.g. load a module which runs a test which loads a PDF before a
module triggering a warning and the warning won't be visible, other
way around it will.

Except ofc while we have an override to PdfFileReader it's not
used *everywhere*, so need to monkeypatch the init.

closes odoo/odoo#60002

Signed-off-by: Xavier Morel (xmo) <xmo@odoo.com>

odoo/tools/pdf.py

@@ -67,6 +67,12 @@ def rotate_pdf(pdf):
         writer.write(_buffer)
         return _buffer.getvalue()
 
+# by default PdfFileReader will overwrite warnings.showwarning which is what
+# logging.captureWarnings does, meaning it essentially reverts captureWarnings
+# every time it's called which is undesirable
+old_init = PdfFileReader.__init__
+PdfFileReader.__init__ = lambda self, stream, strict=True, warndest=None, overwriteWarnings=True: \
+    old_init(self, stream=stream, strict=strict, warndest=None, overwriteWarnings=False)
 
 class OdooPdfFileReader(PdfFileReader):
     # OVERRIDE of PdfFileReader to add the management of multiple embedded files.