fix: use \ as path delim on Windows when executing custom actions (#1077)

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/ViewModels/ExecuteCustomAction.cs

@@ -1,4 +1,5 @@
-using System.Threading.Tasks;
+using System;
+using System.Threading.Tasks;
 
 namespace SourceGit.ViewModels
 {
@@ -13,23 +14,23 @@ public Models.CustomAction CustomAction
         public ExecuteCustomAction(Repository repo, Models.CustomAction action)
         {
             _repo = repo;
-            _args = action.Arguments.Replace("${REPO}", _repo.FullPath);
+            _args = action.Arguments.Replace("${REPO}", GetWorkdir());
             CustomAction = action;
             View = new Views.ExecuteCustomAction() { DataContext = this };
         }
 
         public ExecuteCustomAction(Repository repo, Models.CustomAction action, Models.Branch branch)
         {
             _repo = repo;
-            _args = action.Arguments.Replace("${REPO}", _repo.FullPath).Replace("${BRANCH}", branch.FriendlyName);
+            _args = action.Arguments.Replace("${REPO}", GetWorkdir()).Replace("${BRANCH}", branch.FriendlyName);
             CustomAction = action;
             View = new Views.ExecuteCustomAction() { DataContext = this };
         }
 
         public ExecuteCustomAction(Repository repo, Models.CustomAction action, Models.Commit commit)
         {
             _repo = repo;
-            _args = action.Arguments.Replace("${REPO}", _repo.FullPath).Replace("${SHA}", commit.SHA);
+            _args = action.Arguments.Replace("${REPO}", GetWorkdir()).Replace("${SHA}", commit.SHA);
             CustomAction = action;
             View = new Views.ExecuteCustomAction() { DataContext = this };
         }
@@ -51,6 +52,11 @@ public override Task<bool> Sure()
             });
         }
 
+        private string GetWorkdir()
+        {
+            return OperatingSystem.IsWindows() ? _repo.FullPath.Replace("/", "\\") : _repo.FullPath;
+        }
+
         private readonly Repository _repo = null;
         private string _args = string.Empty;
     }