fix: prefer real undo filenames over /dev/null (#23006)

packages/opencode/src/cli/cmd/tui/util/revert-diff.ts

@@ -0,0 +1,24 @@
+import { parsePatch } from "diff"
+
+export function getRevertDiffFiles(diffText: string) {
+  if (!diffText) return []
+
+  try {
+    return parsePatch(diffText).map((patch) => {
+      const filename = [patch.newFileName, patch.oldFileName].find((item) => item && item !== "/dev/null") ?? "unknown"
+      return {
+        filename: filename.replace(/^[ab]\//, ""),
+        additions: patch.hunks.reduce(
+          (sum, hunk) => sum + hunk.lines.filter((line) => line.startsWith("+")).length,
+          0,
+        ),
+        deletions: patch.hunks.reduce(
+          (sum, hunk) => sum + hunk.lines.filter((line) => line.startsWith("-")).length,
+          0,
+        ),
+      }
+    })
+  } catch {
+    return []
+  }
+}