From 14a7e601f10defb76dca752f8d02f3a6d5cf2782 Mon Sep 17 00:00:00 2001
From: safronov <Safronov.ag@gmail.com>
Date: Thu, 10 Feb 2022 01:08:20 +0300
Subject: [PATCH] Fix possible race condition

---
 YAFC/YAFC.csproj               |  2 +-
 YAFCmodel/Model/ProjectPage.cs | 22 +++++++++++-----------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/YAFC/YAFC.csproj b/YAFC/YAFC.csproj
index 3465c04f..d84d60a9 100644
--- a/YAFC/YAFC.csproj
+++ b/YAFC/YAFC.csproj
@@ -2,7 +2,7 @@
 
     <PropertyGroup>
         <LangVersion>8</LangVersion>
-        <OutputType>Exe</OutputType>
+        <OutputType>WinExe</OutputType>
         <TargetFramework>netcoreapp3.1</TargetFramework>
 		<RuntimeIdentifiers>win-x64;linux-x64;osx-x64</RuntimeIdentifiers>
 		<PlatformTarget>x64</PlatformTarget>
diff --git a/YAFCmodel/Model/ProjectPage.cs b/YAFCmodel/Model/ProjectPage.cs
index 098bb7bf..c9037a20 100644
--- a/YAFCmodel/Model/ProjectPage.cs
+++ b/YAFCmodel/Model/ProjectPage.cs
@@ -83,31 +83,31 @@ protected internal override void ThisChanged(bool visualOnly)
             // Dont propagate page changes to project
         }
 
-        public Task<string> ExternalSolve()
-        {
-            currentSolvingVersion = actualVersion;
-            return content.Solve(this);
-        }
-
-        private async void RunSolveJob()
+        public async Task<string> ExternalSolve()
         {
+            if (!IsSolutionStale())
+                return modelError;
             currentSolvingVersion = actualVersion;
             try
             {
                 var error = await content.Solve(this);
                 await Ui.EnterMainThread();
-                if (modelError != error)
-                    modelError = error;
-                contentChanged?.Invoke(false);
+                return error;
             }
             finally
             {
                 await Ui.EnterMainThread();
                 lastSolvedVersion = currentSolvingVersion;
                 currentSolvingVersion = 0;
-                CheckSolve();
             }
         }
+
+        private async void RunSolveJob()
+        {
+            modelError = await ExternalSolve();
+            contentChanged?.Invoke(false);
+            CheckSolve();
+        }
     }
 
     public abstract class ProjectPageContents : ModelObject<ModelObject>