fix(vcs): preserve batched patch boundaries (#25787)

packages/opencode/src/project/vcs.ts

@@ -85,7 +85,9 @@ const fileFromPatchChunk = (chunk: string) => {
 }
 
 const splitGitPatch = (patch: Git.Patch) => {
-  const starts = [...patch.text.matchAll(/^diff --git /gm)].map((match) => match.index)
+  const starts = [...patch.text.matchAll(/(?:^|\n)diff --git /g)].map((match) =>
+    match[0].startsWith("\n") ? match.index + 1 : match.index,
+  )
   const chunks = starts.map((start, index) => patch.text.slice(start, starts[index + 1] ?? patch.text.length))
   if (!patch.truncated) return chunks
   return chunks.slice(0, -1)

packages/opencode/test/project/vcs.test.ts

@@ -1,5 +1,6 @@
 import { $ } from "bun"
 import { afterEach, describe, expect, test } from "bun:test"
+import { parsePatch } from "diff"
 import { Effect } from "effect"
 import fs from "fs/promises"
 import path from "path"
@@ -288,6 +289,32 @@ describe("Vcs diff", () => {
     })
   })
 
+  test(
+    "diff('git') keeps carriage returns inside patch hunks",
+    async () => {
+      await using tmp = await tmpdir({ git: true })
+      await fs.writeFile(path.join(tmp.path, "file.txt"), "keep\nsame\rdiff --git inside\ndelete\n", "utf-8")
+      await $`git add .`.cwd(tmp.path).quiet()
+      await $`git commit --no-gpg-sign -m "add file"`.cwd(tmp.path).quiet()
+      await fs.writeFile(path.join(tmp.path, "file.txt"), "keep\nadd\nsame\rdiff --git inside\n", "utf-8")
+
+      await withVcsOnly(tmp.path, async () => {
+        const diff = await AppRuntime.runPromise(
+          Effect.gen(function* () {
+            const vcs = yield* Vcs.Service
+            return yield* vcs.diff("git")
+          }),
+        )
+        const file = diff.find((item) => item.file === "file.txt")
+
+        expect(file?.patch).toContain(" same\rdiff --git inside")
+        expect(file?.patch).toContain("-delete")
+        expect(() => parsePatch(file?.patch ?? "")).not.toThrow()
+      })
+    },
+    20_000,
+  )
+
   test("diff('branch') returns changes against default branch", async () => {
     await using tmp = await tmpdir({ git: true })
     await $`git branch -M main`.cwd(tmp.path).quiet()

packages/ui/src/components/session-diff.test.ts

@@ -34,4 +34,20 @@ describe("session diff", () => {
     expect(text(view, "deletions")).toBe("one\n")
     expect(text(view, "additions")).toBe("two\n")
   })
+
+  test("ignores malformed persisted patches", () => {
+    const diff = {
+      file: "a.ts",
+      patch:
+        "diff --git a/a.ts b/a.ts\nindex ff4ceb2..65a1de0 100644\n--- a/a.ts\n+++ b/a.ts\n@@ -1,3 +1,3 @@\n keep\n+add\n same\r",
+      additions: 1,
+      deletions: 1,
+      status: "modified" as const,
+    }
+    const view = normalize(diff)
+
+    expect(view.patch).toBe(diff.patch)
+    expect(text(view, "deletions")).toBe("")
+    expect(text(view, "additions")).toBe("")
+  })
 })

packages/ui/src/components/session-diff.ts

@@ -27,8 +27,8 @@ const cache = new Map<string, FileDiffMetadata>()
 
 function patch(diff: ReviewDiff) {
   if (typeof diff.patch === "string") {
+    try {
       const [patch] = parsePatch(diff.patch)
-
       const beforeLines = []
       const afterLines = []
 
@@ -47,6 +47,9 @@ function patch(diff: ReviewDiff) {
       }
 
       return { before: beforeLines.join("\n"), after: afterLines.join("\n"), patch: diff.patch }
+    } catch {
+      return { before: "", after: "", patch: diff.patch }
+    }
   }
   return {
     before: "before" in diff && typeof diff.before === "string" ? diff.before : "",