testlib: Silence all Qt logging in selftests

Otherwise random debug messages from Qt might mess up the expected vs
actual results.

Task-number: QTQAINFRA-1631
Change-Id: I855d31274f8261f8b125df23409353f7101be0e4
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
(cherry picked from commit 3ae03c3585df7247f5699eeaa70e1bedf47f6d5b)

2 files changed, 11 insertions, 1 deletions

diff --git a/tests/auto/testlib/selftests/generate_expected_output.py b/tests/auto/testlib/selftests/generate_expected_output.py
index 202c4cc426..1ee767cc97 100755
--- a/tests/auto/testlib/selftests/generate_expected_output.py
+++ b/tests/auto/testlib/selftests/generate_expected_output.py
@@ -186,7 +186,13 @@ def generateTestData(testname, clean,
 
 def main(name, *args):
     """Minimal argument parsing and driver for the real work"""
-    os.environ['LC_ALL'] = 'C'
+    os.environ.update(
+        LC_ALL = 'C', # Use standard locale
+        # Avoid interference from any qtlogging.ini files, e.g. in
+        # /etc/xdg/QtProject/, (must match tst_selftests.cpp's
+        # processEnvironment()'s value):
+        QT_LOGGING_RULES = '*.debug=true;qt.*=false')
+
     herePath = os.getcwd()
     cleaner = Cleaner(herePath, name)
 
diff --git a/tests/auto/testlib/selftests/tst_selftests.cpp b/tests/auto/testlib/selftests/tst_selftests.cpp
index e7123fc059..8164c53b67 100644
--- a/tests/auto/testlib/selftests/tst_selftests.cpp
+++ b/tests/auto/testlib/selftests/tst_selftests.cpp
@@ -567,6 +567,10 @@ static QProcessEnvironment processEnvironment()
             if (useVariable)
                 result.insert(key, systemEnvironment.value(key));
         }
+        // Avoid interference from any qtlogging.ini files, e.g. in /etc/xdg/QtProject/:
+        result.insert(QStringLiteral("QT_LOGGING_RULES"),
+                      // Must match generate_expected_output.py's main()'s value:
+                      QStringLiteral("*.debug=true;qt.*=false"));
     }
     return result;
 }