Check for non ASCII characters in CI

Recently it was found that some files contain non ASCII charaters. The added
CI tests checks for files which contain non ASCII characters. Test fails if
non ASCII characters are found in a commit.

.gitlab-ci.yml

@@ -181,6 +181,24 @@ FileEndCheck:
     - git fetch upstream
     - scripts/check-file-ending.sh upstream
 
+NonASCIICharacterCheck:
+  stage: checkFormat
+  image: alpine
+  tags:
+    - docker
+  only:
+    refs:
+      - merge_requests
+    variables:
+      - $CI_MERGE_REQUEST_PROJECT_PATH == "computing/cbmroot" && $CI_MERGE_REQUEST_TARGET_BRANCH_NAME == "master"
+      - $CI_MERGE_REQUEST_PROJECT_PATH == "computing/cbmroot" && $CI_MERGE_REQUEST_TARGET_BRANCH_NAME =~ /^DC_.*$/
+  script:
+    # Get the upstream repository manually. I did not find any other way to have it for
+    # comparison
+    - apk update && apk add git bash file pcre-tools
+    - scripts/connect_upstream_repo.sh $CI_MERGE_REQUEST_PROJECT_URL
+    - git fetch upstream
+    - scripts/check-non-ascii-characters.sh upstream
 
 FileLicenceCheck:
   stage: checkFormat

scripts/check-non-ascii-characters.sh

+#!/bin/bash
+# Copyright (C) 2025 GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt
+# SPDX-License-Identifier: GPL-3.0-only
+# First commited by Florian Uhlig
+
+
+if [[ $# -eq 1 ]]; then
+  UPSTREAM=$1
+else
+  if [ -z $UPSTREAM ]; then
+    UPSTREAM=$(git remote -v | grep git.cbm.gsi.de[:/]computing/cbmroot | cut -f1 | uniq)
+    if [ -z $UPSTREAM ]; then
+      echo "Error: Name of upstream repository not provided and not found by automatic means"
+      echo 'Please provide if by checking your remotes with "git remote -v" and exporting UPSTREAM'
+      echo "or passing as an argument"
+      exit -1
+    fi
+  fi
+fi
+echo "Upstream name is :" $UPSTREAM
+
+BASE_COMMIT=$UPSTREAM/master
+CHANGED_FILES=$(git diff --name-only $BASE_COMMIT)
+for file in $CHANGED_FILES; do
+  result=$(file $file | grep UTF-8)
+  if [[ "$result" != "" ]]; then
+    echo " "
+    echo "File $file contains non ASCII characters"
+    pcregrep --color='auto' -n "[\x80-\xFF]" $file
+    echo " "
+    okay=false
+  fi
+done
+
+if [[ "$okay" = "false" ]]; then
+  echo ""
+  echo "There are files which contain non ASCII characters"
+  echo "Test failed"
+  exit 1
+else
+  exit 0
+fi
+