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..191a464e1a11af2e393d211b269652b2a53077c3 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() {
+  // 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())

[dhollowa, 2012/07/09 20:26:06]

Shouldn't this be:
  if (meta_table_.GetVersionNumber() < meta_table_.GetCompatibleVersionNumber())
...

[Ivan Korotkov, 2012/07/09 20:51:04]

Ouch, you must be right. The test passed because there was a migration to verson
46 which still incremented the version field.

[Peter Kasting, 2012/07/09 21:22:01]

I'm sorry for suggesting this incorrect code to Ivan in the first place!

Ivan, you have LGTM in advance from me to fix/land/merge this.  (Feel free to
TBR.)

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