fix: prevent staging conflicted files (#1555)

It was possible to stage a file with conflicts (double tap, space,
enter, or a stage button).  As a result it would no longer be shown as
conflicted, and the user could no longer solve the conflict in any way
(use theirs, use mine, or execute merge tool), not even after unstaging
again.

Now conflicted files are ignored when staging.

Author: sina-hide

src/ViewModels/WorkingCopy.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using System.Threading.Tasks;
 
 using Avalonia.Controls;
@@ -1870,7 +1871,11 @@ private void UpdateInProgressState()
 
         private async void StageChanges(List<Models.Change> changes, Models.Change next)
         {
-            var count = changes.Count;
+            var nonConflictChanges = HasUnsolvedConflicts
+                ? changes.Where(c => !c.IsConflicted).ToList()
+                : changes;
+
+            var count = nonConflictChanges.Count;
             if (count == 0)
                 return;
 
@@ -1890,7 +1895,7 @@ private async void StageChanges(List<Models.Change> changes, Models.Change next)
                 var pathSpecFile = Path.GetTempFileName();
                 await using (var writer = new StreamWriter(pathSpecFile))
                 {
-                    foreach (var c in changes)
+                    foreach (var c in nonConflictChanges)
                         await writer.WriteLineAsync(c.Path);
                 }
 

src/Views/ChangeCollectionView.axaml.cs

@@ -186,7 +186,10 @@ public Models.Change GetNextChangeWithoutSelection()
 
             var set = new HashSet<string>();
             foreach (var c in selected)
-                set.Add(c.Path);
+            {
+                if (!c.IsConflicted)
+                    set.Add(c.Path);
+            }
 
             if (Content is ViewModels.ChangeCollectionAsTree tree)
             {