Adjust Git Status Parsing to Better Handle Null Chars (#2132)

### Description

Fixes an issue with git status parsing where the substring indexing was
off-by-one when creating the file string due to an index being
incremented before creating a substring.

Fixes this by incrementing the current string index *after* returning
the correct substring.

The related issue is marked as a Tahoe bug, the Tahoe bug is that Tahoe
now shows the null character as a %00 at the end of the label, where
previous macOS versions did not. This change is retroactive however as
it is a bug fix.

### Related Issues

* closes #2119 

### Checklist

- [x] I read and understood the [contributing
guide](https://github.com/CodeEditApp/CodeEdit/blob/main/CONTRIBUTING.md)
as well as the [code of
conduct](https://github.com/CodeEditApp/CodeEdit/blob/main/CODE_OF_CONDUCT.md)
- [x] The issues this PR addresses are related to each other
- [x] My changes generate no new warnings
- [x] My code builds and runs on my machine
- [x] My changes are all related to the related issue above
- [x] I documented my code

### Screenshots

N/A

Author: thecoolwinter

CodeEdit/Features/SourceControl/Client/GitClient+Status.swift

@@ -36,11 +36,25 @@ extension GitClient {
     /// - Throws: Can throw ``GitClient/GitClientError`` errors if it finds unexpected output.
     func getStatus() async throws -> Status {
         let output = try await run("status -z --porcelain=2 -u")
+        return try parseStatusString(output)
+    }
+
+    /// Parses a status string from ``getStatus()`` and returns a ``Status`` object if possible.
+    /// - Parameter output: The git output from running `status`. Expects a porcelain v2 string.
+    /// - Returns: A status object if parseable.
+    func parseStatusString(_ output: borrowing String) throws -> Status {
+        let endsInNull = output.last == Character(UnicodeScalar(0))
+        let endIndex: String.Index
+        if endsInNull && output.count > 1 {
+            endIndex = output.index(before: output.endIndex)
+        } else {
+            endIndex = output.endIndex
+        }
 
         var status = Status(changedFiles: [], unmergedChanges: [], untrackedFiles: [])
 
         var index = output.startIndex
-        while index < output.endIndex {
+        while index < endIndex {
             let typeIndex = index
 
             // Move ahead no matter what.
@@ -100,7 +114,11 @@ extension GitClient {
             }
             index = newIndex
         }
-        index = output.index(after: index)
+        defer {
+            if index < output.index(before: output.endIndex) {
+                index = output.index(after: index)
+            }
+        }
         return output[startIndex..<index]
     }
 
@@ -147,7 +165,8 @@ extension GitClient {
             try moveToNextSpace(from: &index, output: output)
         }
         try moveOneChar(from: &index, output: output)
-        let filename = String(try substringToNextNull(from: &index, output: output))
+        let substring = try substringToNextNull(from: &index, output: output)
+        let filename = String(substring)
         return GitChangedFile(
             status: status,
             stagedStatus: stagedStatus,

CodeEditTests/Features/SourceControl/GitClientTests.swift

@@ -0,0 +1,27 @@
+//
+//  GitClientTests.swift
+//  CodeEditTests
+//
+//  Created by Khan Winter on 9/11/25.
+//
+
+import Testing
+@testable import CodeEdit
+
+@Suite
+struct GitClientTests {
+    @Test
+    func statusParseNullAtEnd() throws {
+        try withTempDir { dirURL in
+            // swiftlint:disable:next line_length
+            let string = "1 .M N... 100644 100644 100644 eaef31cfa2a22418c00d7477da0b7151d122681e eaef31cfa2a22418c00d7477da0b7151d122681e CodeEdit/Features/SourceControl/Client/GitClient+Status.swift\01 AM N... 000000 100644 100644 0000000000000000000000000000000000000000 e0f5ce250b32cf6610a284b7a33ac114079f5159 CodeEditTests/Features/SourceControl/GitClientTests.swift\0"
+            let client = GitClient(directoryURL: dirURL, shellClient: .live())
+            let status = try client.parseStatusString(string)
+
+            #expect(status.changedFiles.count == 2)
+            // No null string at the end
+            #expect(status.changedFiles[0].fileURL.lastPathComponent == "GitClient+Status.swift")
+            #expect(status.changedFiles[1].fileURL.lastPathComponent == "GitClientTests.swift")
+        }
+    }
+}