[FIX] base: decode wkhtmltopdf errors

In some cases, wkhtmltopdf might exit with an error (e.g.: a memory
limit). In such cases, we want to show to the user the error returned by
wkhtmltopdf. Previously, this message was only displayed in binary
format (displayed as "Message: b'My error\n'") which is not user-friendly.
We want this message to be decoded so that it is a bare string
(displayed as "Message: My error").

closes odoo#114586

X-original-commit: 40212c1
Signed-off-by: Vincent Schippefilt (vsc) <vsc@odoo.com>
Signed-off-by: Desausoi Laurent (lade) <lade@odoo.com>

Author: lade-odoo

odoo/addons/base/models/ir_actions_report.py

@@ -5,7 +5,7 @@
 from odoo import api, fields, models, tools, SUPERUSER_ID, _
 from odoo.exceptions import UserError, AccessError
 from odoo.tools.safe_eval import safe_eval, time
-from odoo.tools.misc import find_in_path
+from odoo.tools.misc import find_in_path, ustr
 from odoo.tools import check_barcode_encoding, config, is_html_empty, parse_version
 from odoo.http import request
 from odoo.osv.expression import NEGATIVE_TERM_OPERATORS, FALSE_DOMAIN
@@ -453,6 +453,7 @@ def _run_wkhtmltopdf(
             wkhtmltopdf = [_get_wkhtmltopdf_bin()] + command_args + files_command_args + paths + [pdf_report_path]
             process = subprocess.Popen(wkhtmltopdf, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
             out, err = process.communicate()
+            err = ustr(err)
 
             if process.returncode not in [0, 1]:
                 if process.returncode == -11: