enhance: file rename detection and path resolution in file history

src/Commands/CompareRevisions.cs

@@ -8,7 +8,7 @@ namespace SourceGit.Commands
     {
         [GeneratedRegex(@"^([MADC])\s+(.+)$")]
         private static partial Regex REG_FORMAT();
-        [GeneratedRegex(@"^R[0-9]{0,4}\s+(.+)$")]
+        [GeneratedRegex(@"^R[0-9]{0,4}\s+(.+)\s+(.+)$")]
         private static partial Regex REG_RENAME_FORMAT();
 
         public CompareRevisions(string repo, string start, string end)
@@ -51,7 +51,11 @@ namespace SourceGit.Commands
                 match = REG_RENAME_FORMAT().Match(line);
                 if (match.Success)
                 {
-                    var renamed = new Models.Change() { Path = match.Groups[1].Value };
+                    var renamed = new Models.Change()
+                    {
+                        OriginalPath = match.Groups[1].Value,
+                        Path = match.Groups[2].Value
+                    };
                     renamed.Set(Models.ChangeState.Renamed);
                     _changes.Add(renamed);
                 }

src/Commands/QueryCommits.cs

@@ -43,7 +43,7 @@ namespace SourceGit.Commands
             }
             else if (method == Models.CommitSearchMethod.ByFile)
             {
-                search += $"-- \"{filter}\"";
+                search += $"--follow -- \"{filter}\"";
             }
             else
             {

src/Commands/QueryFilePathInRevision.cs

@@ -0,0 +1,124 @@
+using System;
+using System.Collections.Generic;
+using System.Text.RegularExpressions;
+
+namespace SourceGit.Commands
+{
+    public partial class QueryFilePathInRevision : Command
+    {
+        [GeneratedRegex(@"^R[0-9]{0,4}\s+(.+)\s+(.+)$")]
+        private static partial Regex REG_RENAME_FORMAT();
+
+        public QueryFilePathInRevision(string repo, string revision, string currentPath)
+        {
+            WorkingDirectory = repo;
+            Context = repo;
+            _revision = revision;
+            _currentPath = currentPath;
+        }
+
+        public string Result()
+        {
+            if (CheckPathExistsInRevision(_currentPath))
+                return _currentPath;
+
+            string mappedPath = FindRenameHistory();
+            return mappedPath ?? _currentPath;
+        }
+
+        private bool CheckPathExistsInRevision(string path)
+        {
+            Args = $"ls-tree -r {_revision} -- \"{path}\"";
+            var rs = ReadToEnd();
+            return rs.IsSuccess && !string.IsNullOrEmpty(rs.StdOut);
+        }
+
+        private string FindRenameHistory()
+        {
+            var fileHistory = BuildFileHistory();
+            if (fileHistory == null || fileHistory.Count == 0)
+                return null;
+
+            foreach (var entry in fileHistory)
+            {
+                if (!IsTargetRevisionBefore(entry.CommitSHA))
+                    continue;
+
+                if (CheckPathExistsInRevision(entry.OldPath))
+                    return entry.OldPath;
+            }
+
+            if (fileHistory.Count > 0)
+            {
+                var oldestPath = fileHistory[^1].OldPath;
+                if (CheckPathExistsInRevision(oldestPath))
+                    return oldestPath;
+            }
+
+            return null;
+        }
+
+        private bool IsTargetRevisionBefore(string commitSHA)
+        {
+            Args = $"merge-base --is-ancestor {_revision} {commitSHA}";
+            var rs = ReadToEnd();
+            return rs.IsSuccess;
+        }
+
+        private List<RenameHistoryEntry> BuildFileHistory()
+        {
+            Args = $"log --follow --name-status --pretty=format:\"commit %H\" -M -- \"{_currentPath}\"";
+            var rs = ReadToEnd();
+            if (!rs.IsSuccess)
+                return null;
+
+            var result = new List<RenameHistoryEntry>();
+            var lines = rs.StdOut.Split(new[] { '\n', '\r' }, StringSplitOptions.RemoveEmptyEntries);
+
+            string currentCommit = null;
+            string currentPath = _currentPath;
+
+            foreach (var t in lines)
+            {
+                var line = t.Trim();
+
+                if (line.StartsWith("commit ", StringComparison.Ordinal))
+                {
+                    currentCommit = line.Substring("commit ".Length);
+                    continue;
+                }
+
+                var match = REG_RENAME_FORMAT().Match(line);
+                if (match.Success && currentCommit != null)
+                {
+                    var oldPath = match.Groups[1].Value;
+                    var newPath = match.Groups[2].Value;
+
+                    if (newPath == currentPath)
+                    {
+                        result.Add(new RenameHistoryEntry
+                        {
+                            CommitSHA = currentCommit,
+                            OldPath = oldPath,
+                            NewPath = newPath
+                        });
+
+                        currentPath = oldPath;
+                    }
+                }
+            }
+
+            return result;
+        }
+
+        private class RenameHistoryEntry
+        {
+            public string CommitSHA { get; set; }
+            public string OldPath { get; set; }
+            public string NewPath { get; set; }
+        }
+
+        private readonly string _revision;
+        private readonly string _currentPath;
+    }
+}