Truncate large data URL before storing them in history DB

BUG=851650

Change-Id: I56d69fa06ec030abad513ab61820dfb983f0473e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2530196
Commit-Queue: Min Qin <qinmin@chromium.org>
Reviewed-by: Xing Liu <xingliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826956}

chrome/browser/download/download_history.cc

@@ -57,6 +57,24 @@
 
 namespace {
 
+// Max data url size to be stored in history DB.
+const size_t kMaxDataURLSize = 1024u;
+
+// If there is a data URL at the end of the url chain, truncate it if it is too
+// long.
+void TruncatedDataUrlAtTheEndIfNeeded(std::vector<GURL>* url_chain) {
+  if (url_chain->empty())
+    return;
+  GURL* url = &url_chain->back();
+  if (url->SchemeIs(url::kDataScheme)) {
+    const std::string& data_url = url->spec();
+    if (data_url.size() > kMaxDataURLSize) {
+      GURL truncated_url(data_url.substr(0, kMaxDataURLSize));
+      url->Swap(&truncated_url);
+    }
+  }
+}
+
 // Per-DownloadItem data. This information does not belong inside DownloadItem,
 // and keeping maps in DownloadHistory from DownloadItem to this information is
 // error-prone and complicated. Unfortunately, DownloadHistory::removing_*_ and
@@ -157,6 +175,7 @@ history::DownloadRow GetDownloadRow(download::DownloadItem* item) {
   download.by_ext_id = by_ext_id;
   download.by_ext_name = by_ext_name;
   download.download_slice_info = history::GetHistoryDownloadSliceInfos(*item);
+  TruncatedDataUrlAtTheEndIfNeeded(&download.url_chain);
   return download;
 }
 
@@ -299,8 +318,10 @@ void DownloadHistory::LoadHistoryDownloads(
         history::ToContentDownloadState(row.state);
     download::DownloadInterruptReason history_reason =
         history::ToContentDownloadInterruptReason(row.interrupt_reason);
+    std::vector<GURL> url_chain = row.url_chain;
+    TruncatedDataUrlAtTheEndIfNeeded(&url_chain);
     download::DownloadItem* item = notifier_.GetManager()->CreateDownloadItem(
-        row.guid, loading_id_, row.current_path, row.target_path, row.url_chain,
+        row.guid, loading_id_, row.current_path, row.target_path, url_chain,
         row.referrer_url, row.site_url, row.tab_url, row.tab_referrer_url,
         base::nullopt, row.mime_type, row.original_mime_type, row.start_time,
         row.end_time, row.etag, row.last_modified, row.received_bytes,

chrome/browser/download/download_history_unittest.cc

@@ -838,4 +838,31 @@ TEST_F(DownloadHistoryTest, RemoveClearedItemFromHistory) {
   ExpectDownloadsRemoved(ids);
 }
 
+// Test that large data URL will be truncated before being inserted into
+// history.
+TEST_F(DownloadHistoryTest, CreateLargeDataURLCompletedItem) {
+  // Create a fresh item not from download DB
+  CreateDownloadHistory({});
+
+  history::DownloadRow row;
+  std::string data_url = "data:text/html,";
+  data_url.append(std::string(2048, 'a'));
+  InitBasicItem(FILE_PATH_LITERAL("/foo/bar.pdf"), data_url.c_str(),
+                "http://example.com/referrer.html",
+                download::DownloadItem::IN_PROGRESS, &row);
+
+  // Incomplete download will not be inserted into history.
+  CallOnDownloadCreated(0);
+  ExpectNoDownloadCreated();
+
+  // Completed download should be inserted.
+  EXPECT_CALL(item(0), IsDone()).WillRepeatedly(Return(true));
+  EXPECT_CALL(item(0), GetState())
+      .WillRepeatedly(Return(download::DownloadItem::COMPLETE));
+  row.state = history::DownloadState::COMPLETE;
+  data_url.resize(1024);
+  row.url_chain.back() = GURL(data_url);
+  item(0).NotifyObserversDownloadUpdated();
+  ExpectDownloadCreated(row);
+}
 }  // anonymous namespace