Force WebDatabase version to max(version, compatible version) before migration.

chrome/browser/webdata/web_database.cc

Index: chrome/browser/webdata/web_database.cc
diff --git a/chrome/browser/webdata/web_database.cc b/chrome/browser/webdata/web_database.cc
index 122f3de405216bc702522562dbbdbe49d130503a..a0d9d44818e304d3e4bdc9fa28122dc2c73df852 100644
--- a/chrome/browser/webdata/web_database.cc
+++ b/chrome/browser/webdata/web_database.cc
@@ -158,8 +158,15 @@ sql::InitStatus WebDatabase::Init(const FilePath& db_name) {
 }
 
 sql::InitStatus WebDatabase::MigrateOldVersionsAsNeeded() {
-  // Migrate if necessary.
+  // Ensure that version is not smaller than the compatible version. This is a

[Peter Kasting, 2012/07/06 17:05:12]

Would this be any clearer?:

  // Some malware tries to force protector to re-sign things by lowering the
  // version number, causing migration to fail.  Ensure the version number is at
  // least as high as the compatible version number.
  int current_version = std::max(meta_table_.GetVersionNumber(),
                                 meta_table_.GetCompatibleVersionNumber());
  if (current_version < meta_table_.GetCompatibleVersionNumber())
    ChangeVersion(&meta_table_, current_version, false);

[Ivan Korotkov, 2012/07/09 10:37:38]

Done.

+  // hack for http://crbug.com/135342.
   int current_version = meta_table_.GetVersionNumber();
+  if (current_version < meta_table_.GetCompatibleVersionNumber()) {
+    current_version = meta_table_.GetCompatibleVersionNumber();
+    ChangeVersion(&meta_table_, current_version, false);
+  }
+
+  // Migrate if necessary.
   switch (current_version) {
     // Versions 1 - 19 are unhandled.  Version numbers greater than
     // kCurrentVersionNumber should have already been weeded out by the caller.