mbsync/mutt: Guard against empty mailbox file

bin/mbsync2mutt_mailboxes:
Change script to only copy the temporary mailboxes.rc file in place if
at least one account entry is found (prevents override of existing data
with an empty file, if mbsync returns nothing due to locked secret).

1 files changed, 6 insertions, 1 deletions

diff --git a/bin/mbsync2mutt_mailboxes b/bin/mbsync2mutt_mailboxes
index c98e219..ccf9505 100755
--- a/bin/mbsync2mutt_mailboxes
+++ b/bin/mbsync2mutt_mailboxes
@@ -27,11 +27,16 @@ get_mailboxes_by_account() {
 }
 
 output_mailboxes_to_file() {
+  local tmpfile counter
   tmpfile="$(mktemp)"
+  counter=0
   for account in "${!mailboxes[@]}"; do
     echo -e "mailboxes ${mailboxes[$account]}\n" >> "$tmpfile"
+    counter=$(( "$counter" + 1 ))
   done
-  mv "$tmpfile" "$output_file"
+  if (( "$counter" > 0 )); then
+    mv "$tmpfile" "$output_file"
+  fi
 }
 
 if [ $# -ne 1 ]; then