Bug 1730389 - fix Crash in [@ InvalidArrayIndex_CRASH | nsMsgFilterAfterTheFact::ApplyFilter]. r=benc

Differential Revision: https://phabricator.services.mozilla.com/D127357

--HG--
extra : rebase_source : c9d0839d1c71e81639eb3b330c4efbbd05748b84
extra : amend_source : 539f5fbada39efe1be07814f2c4fb44db52d8796

mailnews/search/src/nsMsgFilterService.cpp

@@ -988,7 +988,7 @@ nsresult nsMsgFilterAfterTheFact::ApplyFilter() {
         MOZ_LOG(FILTERLOGMODULE, LogLevel::Error,
                 ("(Post) Action execution failed with error: %" PRIx32,
                  static_cast<uint32_t>(mFinalResult)));
-        if (loggingEnabled) {
+        if (loggingEnabled && m_searchHitHdrs.Length() > 0) {
           (void)curFilter->LogRuleHitFail(filterAction, m_searchHitHdrs[0],
                                           mFinalResult,
                                           "filterActionFailed"_ns);