rust_uprev: remove the `copy patches` step

Patches no longer have rust's version in them, so we can safely skip
this step now.

BUG=b:266817148
TEST=Unittests

Change-Id: Ib54b2607f25eed5808cd6c544acc5ca3ce3a12f4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/4295527
Tested-by: George Burgess <gbiv@chromium.org>
Commit-Queue: George Burgess <gbiv@chromium.org>
Reviewed-by: Bob Haarman <inglorion@chromium.org>
diff --git a/rust_tools/rust_uprev.py b/rust_tools/rust_uprev.py
index 382d991..5bcb527 100755
--- a/rust_tools/rust_uprev.py
+++ b/rust_tools/rust_uprev.py
@@ -332,27 +332,6 @@
     return template_version, ebuild_path, bootstrap_version
 
 
-def copy_patches(
-    directory: Path, template_version: RustVersion, new_version: RustVersion
-) -> None:
-    patch_path = directory / "files"
-    prefix = "%s-%s-" % (directory.name, template_version)
-    new_prefix = "%s-%s-" % (directory.name, new_version)
-    for f in os.listdir(patch_path):
-        if not f.startswith(prefix):
-            continue
-        logging.info("Copy patch %s to new version", f)
-        new_name = f.replace(str(template_version), str(new_version))
-        shutil.copyfile(
-            os.path.join(patch_path, f),
-            os.path.join(patch_path, new_name),
-        )
-
-    subprocess.check_call(
-        ["git", "add", f"{new_prefix}*.patch"], cwd=patch_path
-    )
-
-
 def create_ebuild(
     template_ebuild: str, pkgatom: str, new_version: RustVersion
 ) -> str:
@@ -648,10 +627,6 @@
             EBUILD_PREFIX.joinpath("eclass/cros-rustc.eclass"), template_version
         ),
     )
-    run_step(
-        "copy patches",
-        lambda: copy_patches(RUST_PATH, template_version, rust_version),
-    )
     template_host_ebuild = EBUILD_PREFIX.joinpath(
         f"dev-lang/rust-host/rust-host-{template_version}.ebuild"
     )
diff --git a/rust_tools/rust_uprev_test.py b/rust_tools/rust_uprev_test.py
index 0c4c91e..c8ceeb7 100755
--- a/rust_tools/rust_uprev_test.py
+++ b/rust_tools/rust_uprev_test.py
@@ -471,52 +471,6 @@
         )
 
     @mock.patch.object(shutil, "copyfile")
-    @mock.patch.object(os, "listdir")
-    @mock.patch.object(subprocess, "check_call")
-    def test_copy_patches(self, mock_call, mock_ls, mock_copy):
-        mock_ls.return_value = [
-            f"rust-{self.old_version}-patch-1.patch",
-            f"rust-{self.old_version}-patch-2-old.patch",
-            f"rust-{self.current_version}-patch-1.patch",
-            f"rust-{self.current_version}-patch-2-new.patch",
-        ]
-        rust_uprev.copy_patches(
-            rust_uprev.RUST_PATH, self.current_version, self.new_version
-        )
-        mock_copy.assert_has_calls(
-            [
-                mock.call(
-                    os.path.join(
-                        rust_uprev.RUST_PATH,
-                        "files",
-                        f"rust-{self.current_version}-patch-1.patch",
-                    ),
-                    os.path.join(
-                        rust_uprev.RUST_PATH,
-                        "files",
-                        f"rust-{self.new_version}-patch-1.patch",
-                    ),
-                ),
-                mock.call(
-                    os.path.join(
-                        rust_uprev.RUST_PATH,
-                        "files",
-                        f"rust-{self.current_version}-patch-2-new.patch",
-                    ),
-                    os.path.join(
-                        rust_uprev.RUST_PATH,
-                        "files",
-                        f"rust-{self.new_version}-patch-2-new.patch",
-                    ),
-                ),
-            ]
-        )
-        mock_call.assert_called_once_with(
-            ["git", "add", f"rust-{self.new_version}-*.patch"],
-            cwd=rust_uprev.RUST_PATH.joinpath("files"),
-        )
-
-    @mock.patch.object(shutil, "copyfile")
     @mock.patch.object(subprocess, "check_call")
     def test_create_rust_ebuild(self, mock_call, mock_copy):
         template_ebuild = f"/path/to/rust-{self.current_version}-r2.ebuild"