From 02a5e036fcf6e570a8146d06294cc8cd411f71d3 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 8 Jan 2020 13:03:55 +0300
Subject: [PATCH] vm: deduplicate checkMultisigPar

Make its logic more clear.
---
 pkg/vm/vm.go | 60 +++++++++++++++++++++++++---------------------------
 1 file changed, 29 insertions(+), 31 deletions(-)

diff --git a/pkg/vm/vm.go b/pkg/vm/vm.go
index 9fffc4e15..88bb74b0a 100644
--- a/pkg/vm/vm.go
+++ b/pkg/vm/vm.go
@@ -1467,46 +1467,44 @@ func checkMultisigPar(v *VM, pkeys [][]byte, sigs [][]byte) bool {
 
 loop:
 	for r := range results {
+		goingForward := true
+
 		taskCount--
-		if r.signum == s1 {
-			if k1+1 == k2 {
-				sigok = r.ok && s1+1 == s2
-				if taskCount != 0 && sigok {
-					continue
-				}
-				break loop
-			} else if r.ok {
-				if s1+1 == s2 {
-					if taskCount != 0 && sigok {
-						continue
-					}
-					break loop
-				}
-				s1++
+		if r.signum == s2 {
+			goingForward = false
+		}
+		if k1+1 == k2 {
+			sigok = r.ok && s1+1 == s2
+			if taskCount != 0 && sigok {
+				continue
 			}
-			k1++
-			taskCount++
-			tasks <- task{pub: v.bytesToPublicKey(pkeys[k1]), signum: s1}
-		} else {
-			if k1+1 == k2 {
-				sigok = r.ok && s1+1 == s2
+			break loop
+		} else if r.ok {
+			if s1+1 == s2 {
 				if taskCount != 0 && sigok {
 					continue
 				}
 				break loop
-			} else if r.ok {
-				if s1+1 == s2 {
-					if taskCount != 0 && sigok {
-						continue
-					}
-					break loop
-				}
+			}
+			if goingForward {
+				s1++
+			} else {
 				s2--
 			}
-			k2--
-			taskCount++
-			tasks <- task{pub: v.bytesToPublicKey(pkeys[k2]), signum: s2}
 		}
+
+		var nextSig, nextKey int
+		if goingForward {
+			k1++
+			nextSig = s1
+			nextKey = k1
+		} else {
+			k2--
+			nextSig = s2
+			nextKey = k2
+		}
+		taskCount++
+		tasks <- task{pub: v.bytesToPublicKey(pkeys[nextKey]), signum: nextSig}
 	}
 
 	close(tasks)