Add bounds check for negative ctrlsrc->z.

chrome/installer/setup/archive_patch_helper_unittest.cc

Index: chrome/installer/setup/archive_patch_helper_unittest.cc
diff --git a/chrome/installer/setup/archive_patch_helper_unittest.cc b/chrome/installer/setup/archive_patch_helper_unittest.cc
index f42ed5baffa6a9d214ec9f50732ec33f76d4496b..8e6c996be48981b4a5f95443582a2d9d85a09fba 100644
--- a/chrome/installer/setup/archive_patch_helper_unittest.cc
+++ b/chrome/installer/setup/archive_patch_helper_unittest.cc
@@ -59,3 +59,29 @@ TEST_F(ArchivePatchHelperTest, Patching) {
   base::FilePath base = data_dir_.AppendASCII("archive2.7z");
   EXPECT_TRUE(base::ContentsEqual(dest, base));
 }
+
+TEST_F(ArchivePatchHelperTest, InvalidDiff_MisalignedCblen) {
+  base::FilePath src = data_dir_.AppendASCII("bin.old");
+  base::FilePath patch = data_dir_.AppendASCII("misaligned_cblen.diff");
+  base::FilePath dest = test_dir_.path().AppendASCII("bin.new");
+  installer::ArchivePatchHelper archive_helper(test_dir_.path(),
+                                               base::FilePath(),
+                                               src,
+                                               dest);
+  archive_helper.set_last_uncompressed_file(patch);
+  // Should fail, but not crash.
+  EXPECT_FALSE(archive_helper.BinaryPatch());
+}
+
+TEST_F(ArchivePatchHelperTest, InvalidDiff_NegativeSeek) {
+  base::FilePath src = data_dir_.AppendASCII("bin.old");
+  base::FilePath patch = data_dir_.AppendASCII("negative_seek.diff");
+  base::FilePath dest = test_dir_.path().AppendASCII("bin.new");
+  installer::ArchivePatchHelper archive_helper(test_dir_.path(),
+                                               base::FilePath(),
+                                               src,
+                                               dest);
+  archive_helper.set_last_uncompressed_file(patch);
+  // Should fail, but not crash.
+  EXPECT_FALSE(archive_helper.BinaryPatch());
+}