From a0cddaea8020b1ca891217df3f918a1a05560e97 Mon Sep 17 00:00:00 2001
From: leo <longshuang@msn.cn>
Date: Mon, 17 Mar 2025 19:53:47 +0800
Subject: [PATCH] feature: support `--ff-only` option for `git merge` command

Signed-off-by: leo <longshuang@msn.cn>
---
 src/Models/MergeMode.cs      |  1 +
 src/ViewModels/Histories.cs  |  6 +++---
 src/ViewModels/Merge.cs      | 12 +++++++-----
 src/ViewModels/Repository.cs |  6 +++---
 4 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/Models/MergeMode.cs b/src/Models/MergeMode.cs
index e4389b32..5dc70030 100644
--- a/src/Models/MergeMode.cs
+++ b/src/Models/MergeMode.cs
@@ -5,6 +5,7 @@
         public static readonly MergeMode[] Supported =
         [
             new MergeMode("Default", "Fast-forward if possible", ""),
+            new MergeMode("Fast-forward", "Refuse to merge when fast-forward is not possible", "--ff-only"),
             new MergeMode("No Fast-forward", "Always create a merge commit", "--no-ff"),
             new MergeMode("Squash", "Squash merge", "--squash"),
             new MergeMode("Don't commit", "Merge without commit", "--no-ff --no-commit"),
diff --git a/src/ViewModels/Histories.cs b/src/ViewModels/Histories.cs
index 0e67915c..01114dd3 100644
--- a/src/ViewModels/Histories.cs
+++ b/src/ViewModels/Histories.cs
@@ -871,7 +871,7 @@ namespace SourceGit.ViewModels
                         return;
 
                     if (_repo.CanCreatePopup())
-                        _repo.ShowAndStartPopup(new Merge(_repo, b, current.Name));
+                        _repo.ShowAndStartPopup(new Merge(_repo, b, current.Name, true));
 
                     e.Handled = true;
                 };
@@ -972,7 +972,7 @@ namespace SourceGit.ViewModels
                 merge.Click += (_, e) =>
                 {
                     if (_repo.CanCreatePopup())
-                        _repo.ShowPopup(new Merge(_repo, branch, current.Name));
+                        _repo.ShowPopup(new Merge(_repo, branch, current.Name, false));
                     e.Handled = true;
                 };
                 submenu.Items.Add(merge);
@@ -1060,7 +1060,7 @@ namespace SourceGit.ViewModels
             merge.Click += (_, e) =>
             {
                 if (_repo.CanCreatePopup())
-                    _repo.ShowPopup(new Merge(_repo, branch, current.Name));
+                    _repo.ShowPopup(new Merge(_repo, branch, current.Name, false));
                 e.Handled = true;
             };
 
diff --git a/src/ViewModels/Merge.cs b/src/ViewModels/Merge.cs
index bde9b66d..be938867 100644
--- a/src/ViewModels/Merge.cs
+++ b/src/ViewModels/Merge.cs
@@ -21,14 +21,14 @@ namespace SourceGit.ViewModels
             set;
         }
 
-        public Merge(Repository repo, Models.Branch source, string into)
+        public Merge(Repository repo, Models.Branch source, string into, bool forceFastForward)
         {
             _repo = repo;
             _sourceName = source.FriendlyName;
 
             Source = source;
             Into = into;
-            Mode = AutoSelectMergeMode();
+            Mode = forceFastForward ? Models.MergeMode.Supported[1] : AutoSelectMergeMode();
             View = new Views.Merge() { DataContext = this };
         }
 
@@ -72,12 +72,14 @@ namespace SourceGit.ViewModels
             var config = new Commands.Config(_repo.FullPath).Get($"branch.{Into}.mergeoptions");
             if (string.IsNullOrEmpty(config))
                 return Models.MergeMode.Supported[0];
-            if (config.Equals("--no-ff", StringComparison.Ordinal))
+            if (config.Equals("--ff-only", StringComparison.Ordinal))
                 return Models.MergeMode.Supported[1];
-            if (config.Equals("--squash", StringComparison.Ordinal))
+            if (config.Equals("--no-ff", StringComparison.Ordinal))
                 return Models.MergeMode.Supported[2];
-            if (config.Equals("--no-commit", StringComparison.Ordinal) || config.Equals("--no-ff --no-commit", StringComparison.Ordinal))
+            if (config.Equals("--squash", StringComparison.Ordinal))
                 return Models.MergeMode.Supported[3];
+            if (config.Equals("--no-commit", StringComparison.Ordinal) || config.Equals("--no-ff --no-commit", StringComparison.Ordinal))
+                return Models.MergeMode.Supported[4];
 
             return Models.MergeMode.Supported[0];
         }
diff --git a/src/ViewModels/Repository.cs b/src/ViewModels/Repository.cs
index f1c43e7c..bf283532 100644
--- a/src/ViewModels/Repository.cs
+++ b/src/ViewModels/Repository.cs
@@ -1516,7 +1516,7 @@ namespace SourceGit.ViewModels
                                 return;
 
                             if (CanCreatePopup())
-                                ShowAndStartPopup(new Merge(this, b, branch.Name));
+                                ShowAndStartPopup(new Merge(this, b, branch.Name, true));
 
                             e.Handled = true;
                         };
@@ -1595,7 +1595,7 @@ namespace SourceGit.ViewModels
                     merge.Click += (_, e) =>
                     {
                         if (CanCreatePopup())
-                            ShowPopup(new Merge(this, branch, _currentBranch.Name));
+                            ShowPopup(new Merge(this, branch, _currentBranch.Name, false));
                         e.Handled = true;
                     };
 
@@ -1876,7 +1876,7 @@ namespace SourceGit.ViewModels
                 merge.Click += (_, e) =>
                 {
                     if (CanCreatePopup())
-                        ShowPopup(new Merge(this, branch, _currentBranch.Name));
+                        ShowPopup(new Merge(this, branch, _currentBranch.Name, false));
                     e.Handled = true;
                 };