manual merged (blame me!)

Build-tools/Do-compile:
  Auto merged
Docs/Makefile.am:
  Auto merged
innobase/btr/btr0cur.c:
  Auto merged
innobase/include/lock0lock.h:
  Auto merged
innobase/include/row0mysql.h:
  Auto merged
innobase/include/srv0srv.h:
  Auto merged
innobase/include/sync0arr.h:
  Auto merged
innobase/include/trx0trx.h:
  Auto merged
innobase/lock/lock0lock.c:
  Auto merged
innobase/srv/srv0srv.c:
  Auto merged
innobase/srv/srv0start.c:
  Auto merged
innobase/sync/sync0arr.c:
  Auto merged
innobase/trx/trx0trx.c:
  Auto merged
sql/ha_innodb.cc:
  Auto merged
sql/sql_insert.cc:
  Auto merged
mysql-test/r/innodb.result:
  to be fixed after the merge

1 files changed, 9 insertions, 2 deletions

diff --git a/innobase/btr/btr0cur.c b/innobase/btr/btr0cur.c
index 2e9194ff30f..be201da4510 100644
--- a/innobase/btr/btr0cur.c
+++ b/innobase/btr/btr0cur.c
@@ -2717,8 +2717,11 @@ btr_estimate_number_of_different_key_vals(
 			rec = page_rec_get_next(rec);
 		}
 		
+
 		if (n_cols == dict_index_get_n_unique_in_tree(index)) {
-			/* We add one because we know that the first record
+
+			/* If there is more than one leaf page in the tree,
+			we add one because we know that the first record
 			on the page certainly had a different prefix than the
 			last record on the previous index page in the
 			alphabetical order. Before this fix, if there was
@@ -2726,7 +2729,11 @@ btr_estimate_number_of_different_key_vals(
 			algorithm grossly underestimated the number of rows
 			in the table. */
 
-			n_diff[n_cols]++;
+			if (btr_page_get_prev(page, &mtr) != FIL_NULL
+			    || btr_page_get_next(page, &mtr) != FIL_NULL) {
+
+				n_diff[n_cols]++;
+			}
 		}
 
 		total_external_size +=