Add election rule context when executing successful vote

x/gov/context.go

@@ -0,0 +1,56 @@
+package gov
+
+import (
+	"context"
+
+	"github.com/iov-one/weave"
+	"github.com/iov-one/weave/x"
+)
+
+type contextKey int // local to the gov module
+
+const (
+	contextKeyGov contextKey = iota
+)
+
+// withElectionSuccess is a private method, as only this module
+// can add a gov signer
+func withElectionSuccess(ctx weave.Context, ruleID []byte) weave.Context {
+	val, _ := ctx.Value(contextKeyGov).([]weave.Condition)
+	if val == nil {
+		return context.WithValue(ctx, contextKeyGov, []weave.Condition{ElectionCondition(ruleID)})
+	}
+
+	return context.WithValue(ctx, contextKeyGov, append(val, ElectionCondition(ruleID)))
+}
+
+// ElectionCondition returns condition for an election rule ID
+func ElectionCondition(ruleID []byte) weave.Condition {
+	return weave.NewCondition("gov", "rule", ruleID)
+}
+
+// Authenticate gets/sets permissions on the given context key
+type Authenticate struct {
+}
+
+var _ x.Authenticator = Authenticate{}
+
+// GetConditions returns permissions previously set on this context
+func (a Authenticate) GetConditions(ctx weave.Context) []weave.Condition {
+	// (val, ok) form to return nil instead of panic if unset
+	val, _ := ctx.Value(contextKeyGov).([]weave.Condition)
+	if val == nil {
+		return nil
+	}
+	return val
+}
+
+// HasAddress returns true iff this address is in GetConditions
+func (a Authenticate) HasAddress(ctx weave.Context, addr weave.Address) bool {
+	for _, s := range a.GetConditions(ctx) {
+		if addr.Equals(s.Address()) {
+			return true
+		}
+	}
+	return false
+}

x/gov/handler.go

@@ -206,9 +206,10 @@ func (h TallyHandler) Deliver(ctx weave.Context, db weave.KVStore, tx weave.Tx)
 		return nil, errors.Wrap(err, "options invalid")
 	}
 
-	// TODO: what do we use for ctx here???
-	// we need to add the election rules somehow
-	return h.executor(ctx, db, opts)
+	// we add the vote ctx here, to authenticate results in the executor
+	// ensure that the gov.Authenticator is used in those Handlers
+	voteCtx := withElectionSuccess(ctx, common.ElectionRuleRef.ID)
+	return h.executor(voteCtx, db, opts)
 }
 
 func (h TallyHandler) validate(ctx weave.Context, db weave.KVStore, tx weave.Tx) (*TallyMsg, *Proposal, error) {