[Bug]: halt-height is not deterministic

[yihuang]

Summary of Bug

Currently halt-height will send a signal to current process, the signal is handled asynchronously, which means there could be more blocks being committed before the signal handler is trigger and stop the consensus state machine, especially in catching up phase where blocks are executed very fast.

Sometimes I use halt-height feature to restore node state to a specific height, I first restore state with a snapshot before that height, then start it with --halt-height <target height>, but with current behavior, it's not guaranteed to stop at the exact height.

Version

Steps to Reproduce

Suggestion

• Add a check in BaseApp.BeginBlocker, do a panic if the height is to be halted, this will ensure the future blocks won't be executed succesfully.

 func (app *BaseApp) BeginBlocker(ctx sdk.Context, req abci.RequestBeginBlock) abci.ResponseBeginBlock {
+       var halt bool
+       switch {
+       case app.haltHeight > 0 && uint64(req.Header.Height) > app.haltHeight:
+               halt = true
+
+       case app.haltTime > 0 && req.Header.Time.Unix() > int64(app.haltTime):
+               halt = true
+       }
+
+       if halt {
+               app.Logger().Info("halting node per configuration", "height", app.haltHeight, "time", app.haltTime)
+               if err := app.Close(); err != nil {
+                       app.Logger().Info("close application failed", "error", err)
+               }
+               panic("halt application")
+       }