lock files to prevent accidents.

preview will only run if the turn worked out.
cannot accidentally run in the game directory.

process/cron/run-eressea

@@ -13,7 +13,12 @@ if [ -d $REPORTS ]; then
 fi
 mkdir $REPORTS
 $BIN/backup-eressea $GAME
+if [ -d test ]; then
+  touch test/execute.lock
+fi
+rm -f execute.lock
 $BIN/run-turn $GAME
+touch execute.lock
 if [ ! -s $ERESSEA/game-$GAME/orders.$TURN ]; then
   echo "server did not create orders for turn $TURN in game $GAME"
   exit 2
@@ -31,3 +36,4 @@ $BIN/compress.sh $GAME $TURN
 $BIN/sendreports.sh $GAME
 $BIN/backup-eressea $GAME
 [ $GAME -lt 4 ] && $BIN/send-summary $GAME
+rm -f test/execute.lock

scripts/run-turn.lua

@@ -182,6 +182,16 @@ function run_turn(rules)
   return result
 end
 
+function file_exists(name)
+    local f=io.open(name,"r")
+    if f~=nil then io.close(f) return true else return false end
+end
+
+if file_exists('execute.lock') then
+    eressea.log.error("Lockfile exists, aborting.")
+    assert(false)
+end
+
 local path = 'scripts'
 if config.install then
     path = config.install .. '/' .. path