CI: restore JUnit output processing in Jenkinsfile

via wrapper which modifies the environment per test

Workaround for https://github.com/google/gtest-parallel/pull/89

Jenkinsfile

@@ -24,7 +24,7 @@ timestamps {
           }
         }
         stage('Integration test') {
-          withEnv(['GTEST_OUTPUT=xml:integration-test.xml']) {
+          withEnv(['GTEST_OUTPUT=xml:integration-XXX-test.xml']) {
             sh 'make install'
             sh 'make inttest'
           }

test/CMakeLists.txt

@@ -102,6 +102,7 @@ add_custom_target(inttest COMMAND
 	# znc-buildmod should use the correct compiler.
 	# https://bugs.gentoo.org/699258 is an example of how it can go wrong.
 	${CMAKE_COMMAND} -E env MAKEFLAGS= CXX=${CMAKE_CXX_COMPILER}
+	"INTTEST_BIN=${CMAKE_CURRENT_BINARY_DIR}/integration/inttest"
 	"${PROJECT_SOURCE_DIR}/third_party/gtest-parallel/gtest-parallel"
-	"${CMAKE_CURRENT_BINARY_DIR}/integration/inttest")
+	"${CMAKE_CURRENT_SOURCE_DIR}/integration/wrapper.py")
 add_dependencies(inttest inttest_bin)

test/integration/wrapper.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2004-2025 ZNC, see the NOTICE file for details.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# The purpose of this file is to fix environment in the parallel execution of
+# the test with filenames of test results - otherwise all of them write to the
+# same file, so it races and produces invalid data
+
+# See also: https://github.com/google/gtest-parallel/pull/89
+
+import os
+import sys
+import re
+import random
+
+flag = re.compile(r'--gtest_filter=(.*)')
+
+test = ''
+for arg in sys.argv:
+    m = flag.search(arg)
+    if m:
+        test = m[1]
+        break
+
+# TODO: perhaps it should be hash of test name instead?
+pid = os.getpid()
+rand = random.randint(0, 1000)
+value = f'{pid}-{rand}'
+for var in ['GTEST_OUTPUT']:
+    if var in os.environ:
+        os.environ[var] = os.environ[var].replace('XXX', value)
+
+binary = os.environ['INTTEST_BIN']
+sys.argv[0] = binary
+
+os.execv(binary, sys.argv)