TS-4050 - Trafficserver is crashing when buckets=0 is configured in cache_promote plugin

[meeramn]

Fix trafficserver crash when buckets=0 is configured in cache_promote plugin and Set buckets default value to be 10

[zwoop]

Much better!

I'll have to check / read the code more thoroughly, but are you sure this isn't now leaking the object when the freelist is empty?

     _freelist.splice(_freelist.begin(), _list, map_it->second);
+        // Check if list is not empty
+        if (!_list.empty()) {
+          _freelist.splice(_freelist.begin(), _list, map_it->second);
+        }

[zwoop]

Yeah, so there's no leak here (sorry, my bad), but I feel these checks are unnecessary. I'd rather change this to have a release assert above this, e.g.

--- a/plugins/experimental/cache_promote/cache_promote.cc
+++ b/plugins/experimental/cache_promote/cache_promote.cc
@@ -249,6 +249,7 @@ public:
     map_it = _map.find(&hash);
     if (_map.end() != map_it) {
       // We have an entry in the LRU
+      TSReleaseAssert(_list.size() > 0); // mismatch in the LRUs hash and list
       if (++(map_it->second->second) >= _hits) {
         // Promoted! Cleanup the LRU, and signal success. Save the promoted entry on the freelist.
        TSDebug(PLUGIN_NAME, "saving the LRUEntry to the freelist");

[meeramn]

Thanks Leif for reviewing. Please take a look at changes and approve.