auto-detect locale from old cluster during upgrade

bin/postgresql-setup.in

@@ -213,6 +213,87 @@ old_data_in_use()
 }
 
 
+# Detect locale settings from old cluster datadir
+# Sets: old_cluster_lc_collate, old_cluster_lc_ctype, old_cluster_locale
+detect_old_cluster_locale()
+{
+    local old_datadir="$1"
+    local old_bindir="$2"
+    local old_port="$3"
+
+    old_cluster_lc_collate=""
+    old_cluster_lc_ctype=""
+    old_cluster_locale=""
+
+    if old_data_in_use; then
+      return 1
+    fi
+
+    # If server is not running, try to start it temporarily
+    debug "old cluster server is not running, attempting temporary start to query locale"
+
+    # Create a temporary socket directory
+    local temp_sockdir=$(mktemp -d 2>/dev/null)
+    if [ $? -ne 0 ] || [ -z "$temp_sockdir" ]; then
+        debug "failed to create temporary socket directory"
+        return 1
+    fi
+
+    local temp_log="$old_datadir/temp_locale_query.log"
+
+    # Try to start server with minimal configuration
+    # Use a different port to avoid conflicts
+    local temp_port=$((old_port + 10000))
+
+    # Start server in background with minimal settings
+    # Use -m fast to speed up startup
+    if "$old_bindir/pg_ctl" -D "$old_datadir" -o "-p $temp_port -c listen_addresses='' -c unix_socket_directories='$temp_sockdir' -c max_connections=5 -c shared_buffers=128kB" start -w -l "$temp_log" -m fast >/dev/null 2>&1; then
+        debug "temporarily started old cluster server on port $temp_port"
+        # Give it a moment to be ready
+        sleep 2
+    else
+        debug "failed to start old cluster server temporarily (see $temp_log for details)"
+        rm -rf "$temp_sockdir"
+        rm -f "$temp_log"
+        return 1
+    fi
+
+
+    # Query locale from template1 database
+    local query="SELECT datcollate, datctype FROM pg_catalog.pg_database WHERE datname = 'template1'"
+    local result
+    local query_port="$temp_port"
+
+    # Perform query
+    local psql_exit_code=0
+    result=$(psql -t -A -h "$temp_sockdir" -p "$query_port" -d template1 -c "$query" 2>/dev/null)
+    psql_exit_code=$?
+
+    # Stop temporary server
+    "$old_bindir/pg_ctl" -D "$old_datadir" stop >/dev/null 2>&1
+    rm -rf "$temp_sockdir"
+    rm -f "$temp_log"
+
+    # Parse result
+    if [ $psql_exit_code -eq 0 ] && [ -n "$result" ]; then
+        # Parse result: datcollate|datctype
+        old_cluster_lc_collate=$(echo "$result" | cut -d'|' -f1 | tr -d ' ')
+        old_cluster_lc_ctype=$(echo "$result" | cut -d'|' -f2 | tr -d ' ')
+        old_cluster_locale="$old_cluster_lc_collate"
+
+        if [ -n "$old_cluster_lc_collate" ] && [ -n "$old_cluster_lc_ctype" ]; then
+            debug "detected locale from old cluster: collate=$old_cluster_lc_collate, ctype=$old_cluster_lc_ctype"
+            return 0
+        fi
+    fi
+
+    # If we couldn't detect it, return failure
+    warn $"Could not automatically detect locale settings from old cluster."
+    warn_q $"You may need to set PGSETUP_INITDB_OPTIONS manually with --lc-collate, --lc-ctype, and --locale options."
+    return 1
+}
+
+
 upgrade()
 {
     local inplace=false
@@ -275,6 +356,39 @@ upgrade()
 
     info $"Upgrading database."
 
+    # Automatically detect locale settings from old cluster if not already set
+    # This addresses Bug 1152556: detect --locale from old datadir automatically
+    local locale_already_set=false
+    if [ -n "$PGSETUP_INITDB_OPTIONS" ]; then
+        if echo "$PGSETUP_INITDB_OPTIONS" | grep -qE -- "--lc-collate|--lc-ctype|--locale"; then
+            locale_already_set=true
+        fi
+    fi
+
+    if [ "$locale_already_set" != "true" ]; then
+        debug "attempting to auto-detect locale from old cluster"
+        if detect_old_cluster_locale "$pgdataold" "$upgradefrom_engine" "$PGPORT"; then
+            # Build initdb options with detected locale
+            local detected_opts="--lc-collate=$old_cluster_lc_collate --lc-ctype=$old_cluster_lc_ctype"
+            if [ -n "$old_cluster_locale" ]; then
+                detected_opts="$detected_opts --locale=$old_cluster_locale"
+            fi
+
+            # Append to existing PGSETUP_INITDB_OPTIONS if set, otherwise set it
+            if [ -n "$PGSETUP_INITDB_OPTIONS" ]; then
+                export PGSETUP_INITDB_OPTIONS="$PGSETUP_INITDB_OPTIONS $detected_opts"
+            else
+                export PGSETUP_INITDB_OPTIONS="$detected_opts"
+            fi
+
+            info $"Auto-detected locale settings from old cluster: $detected_opts"
+        else
+            debug "locale auto-detection failed, proceeding with system default locale"
+        fi
+    else
+        debug "locale options already set in PGSETUP_INITDB_OPTIONS, skipping auto-detection"
+    fi
+
     scls_upgrade_hacks=
     test -n "$upgradefrom_scls" && {
         debug "scls [$upgradefrom_scls] will be enabled"

tmt/tests/virtual/sanity/locale-change/locale.sh

@@ -0,0 +1,100 @@
+#!/bin/bash
+# vim: dict+=/usr/share/beakerlib/dictionary.vim cpt=.,w,b,u,t,i,k
+
+. /usr/share/beakerlib/beakerlib.sh || exit 1
+
+rlJournalStart
+  rlPhaseStartSetup
+    rlRun "git clone \"$REPO_URL\" repo"
+    rlRun "pushd repo"
+    rlRun "git fetch origin \"$PR_HEAD\""
+    rlRun "git checkout FETCH_HEAD"
+    rlRun "cat /etc/fedora-release"
+    rlRun "dnf -y install postgresql16-server"
+
+    rlRun "autoreconf -vfi" 0 "Building and installing postgresql-setup"
+    rlRun "./configure --prefix=/usr"
+    rlRun "make"
+    rlRun "./bin/postgresql-setup --init" 0 "Initializing database dir"
+    rlRun "systemctl start postgresql" 0 "Starting service"
+    rlRun "systemctl is-active postgresql" 0 "Verifying service running"
+  rlPhaseEnd
+
+  rlPhaseStartTest
+    rlRun "su - postgres -c \"
+    createdb testdb;
+    psql -U postgres -d testdb -c \\\"create table users (id serial primary key, name text)\\\";
+    psql -U postgres -d testdb -c \\\"insert into users (name) values ('Alice'), ('Bob'), ('Celine')\\\"
+    \""
+    rlRun "su - postgres -c '
+    psql -U postgres -d testdb -c \"select * from users\"
+    ' > expected.txt"
+
+    echo "Expected:"
+    cat expected.txt
+
+    # change locale (https://wiki.archlinux.org/title/Locale#Make_locale_changes_immediate)
+    rlRun "localectl set-locale LANG=en_GB.UTF-8" 0 "Changing locale"
+    rlRun "unset LANG"
+    rlRun "source /etc/profile.d/lang.sh"
+    rlRun "locale"
+
+    rlRun "dnf -y remove postgresql16*" 0 "Removing postgresql 16"
+    rlRun "dnf -y install postgresql17-upgrade" 0 "Installing postgresql 17"
+    rlRun "./bin/postgresql-setup --upgrade" 0 "Running upgrade"
+
+    rlRun "systemctl start postgresql" 0 "Starting service again"
+    rlRun "systemctl is-active postgresql" 0 "Verifying service running"
+
+    rlRun "su - postgres -c '
+    psql -U postgres -d testdb -c \"select * from users\"
+    ' > actual17.txt"
+
+    echo "Actual:"
+    cat actual17.txt
+
+    rlAssertNotDiffer expected.txt actual17.txt
+
+    rlRun "localectl set-locale LC_COLLATE=en_US.UTF-8" 0 "Changing LC_COLLATE"
+    rlRun "localectl set-locale LC_CTYPE=en_AU.UTF-8" 0 "Changing LC_CTYPE"
+    rlRun "unset LANG"
+    rlRun "source /etc/profile.d/lang.sh"
+    rlRun "locale"
+
+    rlRun "dnf -y remove postgresql17*" 0 "Removing postgresql 17"
+    rlRun "dnf -y install postgresql18-upgrade" 0 "Installing postgresql 18"
+    # TODO: remove if functionality added to the script
+    rlRun "/usr/lib64/pgsql/postgresql-17/bin/pg_checksums -e /var/lib/pgsql/data" 0 "Enabling data checksums for pg18"
+
+    rlRun "su - postgres -c '/usr/lib64/pgsql/postgresql-17/bin/pg_ctl -D /var/lib/pgsql/data -l /var/lib/pgsql/logfile start'" 0 "Starting postgres pre-upgrade"
+    rlRun "su - postgres -c '/usr/lib64/pgsql/postgresql-17/bin/pg_ctl -D /var/lib/pgsql/data status'" 0 "Verifying postgres is running"
+
+    rlRun "./bin/postgresql-setup --upgrade --debug" 1 "Trying to run upgrade"
+    rlRun "su - postgres -c '/usr/lib64/pgsql/postgresql-17/bin/pg_ctl -D /var/lib/pgsql/data stop'" 0 "Stopping old postgres"
+    rlRun "./bin/postgresql-setup --upgrade --debug" 0 "Upgrading"
+
+    rlRun "systemctl start postgresql" 0 "Starting service again"
+    rlRun "systemctl is-active postgresql" 0 "Verifying service running"
+
+    rlRun "su - postgres -c '
+    psql -U postgres -d testdb -c \"select * from users\"
+    ' > actual18.txt"
+
+    echo "Actual:"
+    cat actual18.txt
+
+    rlAssertNotDiffer actual17.txt actual18.txt
+  rlPhaseEnd
+
+  rlPhaseStartCleanup
+    rlRun "popd"
+    rlRun "rm -rf repo"
+    rlRun "echo 'LANG=en_US.UTF-8' > /etc/locale.conf" 0 "Resetting locale"
+    rlRun "unset LANG"
+    rlRun "source /etc/profile.d/lang.sh"
+    rlRun "systemctl stop postgresql" 0 "Stopping postgresql service"
+    rlRun "rm -rf /var/lib/pgsql" 0 "Removing database folder"
+    rlRun "dnf -y remove postgresql*" 0 "Uninstalling postgresql"
+  rlPhaseEnd
+rlJournalPrintText
+rlJournalEnd

tmt/tests/virtual/sanity/locale-change/main.fmf

@@ -0,0 +1,19 @@
+summary: Check if upgrading a database works when using a different locale
+name: locale-change
+require:
+  - make
+  - m4
+  - docbook-utils
+  - help2man
+  - elinks
+  - coreutils
+  - autoconf
+  - automake
+  - autoconf-archive
+  - git
+framework: beakerlib
+contact: pkhartsk@redhat.com
+tag:
+  - fedora-upgrade
+test: ./locale.sh
+