Bug 870460 - Part 2: Close syncconn for edge cases. r=nwgh

--HG--
extra : source : 50368fa3e040a806a0b86c0c6471055f4cb41ae1

extensions/cookie/test/unit/test_cookies_async_failure.js

@@ -458,8 +458,9 @@ function* run_test_5(generator)
   do_check_eq(do_count_cookies(), 0);
 
   // Close the profile. We do not need to wait for completion, because the
-  // database has already been closed.
-  do_close_profile();
+  // database has already been closed. Ensure the cookie file is unlocked.
+  do_close_profile(sub_generator);
+  yield;
 
   // Clean up.
   do_get_cookie_file(profile).remove(false);

netwerk/cookie/nsCookieService.cpp

@@ -55,6 +55,7 @@
 #include "mozilla/storage.h"
 #include "mozilla/AutoRestore.h"
 #include "mozilla/FileUtils.h"
+#include "mozilla/ScopeExit.h"
 #include "mozilla/Telemetry.h"
 #include "nsIConsoleService.h"
 #include "nsVariant.h"
@@ -891,6 +892,10 @@ nsCookieService::TryInitDB(bool aRecreateDB)
     NS_ENSURE_SUCCESS(rv, RESULT_RETRY);
   }
 
+  auto guard = MakeScopeExit([&] {
+    mDefaultDBState->syncConn = nullptr;
+  });
+
   bool tableExists = false;
   mDefaultDBState->syncConn->TableExists(NS_LITERAL_CSTRING("moz_cookies"),
     &tableExists);
@@ -1744,7 +1749,6 @@ nsCookieService::CleanupDefaultDBConnection()
   // asynchronous operations yet, this will synchronously close it; otherwise,
   // it's expected that the caller has performed an AsyncClose prior.
   mDefaultDBState->dbConn = nullptr;
-  mDefaultDBState->syncConn = nullptr;
 
   // Manually null out our listeners. This is necessary because they hold a
   // strong ref to the DBState itself. They'll stay alive until whatever
@@ -2832,8 +2836,6 @@ nsCookieService::Read()
     tuple->cookie = GetCookieFromRow(stmt, attrs);
   }
 
-  mDefaultDBState->syncConn = nullptr;
-
   COOKIE_LOGSTRING(LogLevel::Debug, ("Read(): %zu cookies read", mReadArray.Length()));
 
   return RESULT_OK;