fix: pipefail for dnf exit codes in update script

Author: draphy

update.sh

@@ -463,9 +463,13 @@ do_version_upgrade() {
     download_output=$(mktemp)
     chmod 600 "$download_output"  # Restrict permissions on temp file
 
-    # Use PIPESTATUS to capture dnf exit code, not tee's
-    sudo dnf system-upgrade download --releasever="$target_version" -y 2>&1 | tee "$download_output"
-    if [ "${PIPESTATUS[0]}" -ne 0 ]; then
+    # Use subshell with pipefail to capture dnf exit code correctly
+    local dnf_exit=0
+    (
+        set -o pipefail
+        sudo dnf system-upgrade download --releasever="$target_version" -y 2>&1 | tee "$download_output"
+    ) || dnf_exit=$?
+    if [ "$dnf_exit" -ne 0 ]; then
         # Check if version doesn't exist (catch 404 errors, missing repos, etc.)
         if grep -qiE "unable to find.*releasever|no such.*version|not found|status code: 404|Failed to download metadata|Cannot prepare internal mirrorlist" "$download_output" 2>/dev/null; then
             print_error "Fedora $target_version is not available yet."
@@ -495,9 +499,13 @@ do_version_upgrade() {
 
         if [[ "$retry" =~ ^[Yy](es)?$ ]]; then
             print_warning "Using --allowerasing - review removed packages carefully!"
-            # Use PIPESTATUS to capture dnf exit code, not tee's
-            sudo dnf system-upgrade download --releasever="$target_version" --allowerasing -y 2>&1 | tee "$download_output"
-            if [ "${PIPESTATUS[0]}" -ne 0 ]; then
+            # Use subshell with pipefail to capture dnf exit code correctly
+            local dnf_exit=0
+            (
+                set -o pipefail
+                sudo dnf system-upgrade download --releasever="$target_version" --allowerasing -y 2>&1 | tee "$download_output"
+            ) || dnf_exit=$?
+            if [ "$dnf_exit" -ne 0 ]; then
                 if grep -qiE "unable to find.*releasever|no such.*version|not found|status code: 404|Failed to download metadata|Cannot prepare internal mirrorlist" "$download_output" 2>/dev/null; then
                     print_error "Fedora $target_version is not available."
                     rm -f "$download_output"