refs #6300, fix on main

git-svn-id: file:///svn/toku/tokudb@54569 c7de825b-a66e-492c-adef-691d508d4ae1

ft/ft-flusher.cc

@@ -1220,7 +1220,8 @@ maybe_merge_pinned_leaf_nodes(
 {
     unsigned int sizea = toku_serialize_ftnode_size(a);
     unsigned int sizeb = toku_serialize_ftnode_size(b);
-    if ((sizea + sizeb)*4 > (nodesize*3)) {
+    uint32_t num_leafentries = get_leaf_num_entries(a) + get_leaf_num_entries(b);
+    if (num_leafentries > 1 && (sizea + sizeb)*4 > (nodesize*3)) {
         // the combined size is more than 3/4 of a node, so don't merge them.
         *did_merge = false;
         if (sizea*4 > nodesize && sizeb*4 > nodesize) {

ft/ft-internal.h

@@ -155,6 +155,7 @@ bool toku_ft_nonleaf_is_gorged(FTNODE node, uint32_t nodesize);
 
 enum reactivity get_nonleaf_reactivity (FTNODE node);
 enum reactivity get_node_reactivity (FTNODE node, uint32_t nodesize);
+uint32_t get_leaf_num_entries(FTNODE node);
 
 
 // data of an available partition of a leaf ftnode

ft/ft-ops.cc

@@ -315,7 +315,7 @@ toku_assert_entire_node_in_memory(FTNODE UU() node) {
     paranoid_invariant(is_entire_node_in_memory(node));
 }
 
-static uint32_t
+uint32_t
 get_leaf_num_entries(FTNODE node) {
     uint32_t result = 0;
     int i;