[sql] Prevent recovery against a closed database.

sql/connection.cc

Index: sql/connection.cc
diff --git a/sql/connection.cc b/sql/connection.cc
index 003005a8e6294247df3d5bbea887a54ccd365cd7..9f7eb2bcdcdb29fd981ea45127993dda0de88d18 100644
--- a/sql/connection.cc
+++ b/sql/connection.cc
@@ -260,7 +260,15 @@ void Connection::ReportDiagnosticInfo(int extended_error, Statement* stmt) {
   std::string debug_info;
   const int error = (extended_error & 0xFF);
   if (error == SQLITE_CORRUPT) {
+    // CollectCorruptionInfo() is implemented in terms of sql::Connection,
+    // prevent reentrant calls to the error callback.
+    // TODO(shess): Rewrite IntegrityCheckHelper() in terms of raw SQLite.
+    ErrorCallback original_callback = std::move(error_callback_);
+    reset_error_callback();
+
     debug_info = CollectCorruptionInfo();
+
+    error_callback_ = std::move(original_callback);
   } else {
     debug_info = CollectErrorInfo(extended_error, stmt);
   }