Allow 0 instances to launch

Author: SimonCropp

src/DiffEngine/Guard.cs

@@ -1,8 +1,8 @@
 static class Guard
 {
-    public static void AgainstNegativeAndZero(int value, string argumentName)
+    public static void AgainstNegative(int value, string argumentName)
     {
-        if (value <= 0)
+        if (value < 0)
         {
             throw new ArgumentOutOfRangeException(argumentName);
         }

src/DiffEngine/MaxInstance.cs

@@ -33,14 +33,14 @@ static int GetMaxInstances() =>
 
     public static void SetForAppDomain(int value)
     {
-        Guard.AgainstNegativeAndZero(value, nameof(value));
+        Guard.AgainstNegative(value, nameof(value));
         appDomainMaxInstancesToLaunch = value;
         ResetCapturedValue();
     }
 
     public static void SetForUser(int value)
     {
-        Guard.AgainstNegativeAndZero(value, nameof(value));
+        Guard.AgainstNegative(value, nameof(value));
         EnvironmentHelper.Set("DiffEngine_MaxInstances", value.ToString());
         ResetCapturedValue();
     }

src/DiffEngineTray/Settings/OptionsForm.Designer.cs

@@ -2,7 +2,7 @@
 <Project>
   <PropertyGroup>
     <NoWarn>CS1591;CS0649;NU1608;NU1109</NoWarn>
-    <Version>16.7.1</Version>
+    <Version>16.7.2</Version>
     <AssemblyVersion>1.0.0</AssemblyVersion>
     <PackageTags>Testing, Snapshot, Diff, Compare</PackageTags>
     <Description>Launches diff tools based on file extensions. Designed to be consumed by snapshot testing libraries.</Description>