Add support for signed commits (#3055)

src/git-command-manager.ts

@@ -166,6 +166,16 @@ export class GitCommandManager {
     return output.exitCode === 1
   }
 
+  async getChangedFiles(ref: string, options?: string[]): Promise<string[]> {
+    const args = ['diff', '--name-only']
+    if (options) {
+      args.push(...options)
+    }
+    args.push(ref)
+    const output = await this.exec(args)
+    return output.stdout.split("\n").filter((filename) => filename != '')
+  }
+
   async isDirty(untracked: boolean, pathspec?: string[]): Promise<boolean> {
     const pathspecArgs = pathspec ? ['--', ...pathspec] : []
     // Check untracked changes