merge revision(s) 496591de96b261b8789332c7f8b2bfbd17658955: [Backport #18578]

	st.c: Do not clear entries_bound when calling Hash#shift for empty
	 hash

	tab->entries_bound is used to check if the bins are full in
	rebuild_table_if_necessary.

	Hash#shift against an empty hash assigned 0 to tab->entries_bound, but
	didn't clear the bins. Thus, the table is not rebuilt even when the bins
	are full. Attempting to add a new element into full-bin hash gets stuck.

	This change stops clearing tab->entries_bound in Hash#shift.
	[Bug #18578]
	---
	 st.c                   |  1 -
	 test/ruby/test_hash.rb | 13 +++++++++++++
	 2 files changed, 13 insertions(+), 1 deletion(-)

1 files changed, 0 insertions, 1 deletions

diff --git a/st.c b/st.c
index dd7870562e..9131dc13c2 100644
--- a/st.c
+++ b/st.c
@@ -1356,7 +1356,6 @@ st_shift(st_table *tab, st_data_t *key, st_data_t *value)
 	    return 1;
 	}
     }
-    tab->entries_start = tab->entries_bound = 0;
     if (value != 0) *value = 0;
     return 0;
 }