Bug#19978: INSERT .. ON DUPLICATE erroneously reports some records were

updated.

INSERT ... ON DUPLICATE KEY UPDATE reports that a record was updated when
the duplicate key occurs even if the record wasn't actually changed
because the update values are the same as those in the record.

Now the compare_record() function is used to check whether the record was
changed and the update of a record reported only if the record differs
from the original one.


sql/sql_update.cc:
  Bug#19978: INSERT .. ON DUPLICATE erroneously reports some records were
  updated.
  The compare_record() function was changed to non-static one.
sql/sql_insert.cc:
  Bug#19978: INSERT .. ON DUPLICATE erroneously reports some records were
  updated.
  Now the compare_record() function is used to check whether the record was
  changed and the update of a record reported only if the record differs
  from the original one.
sql/mysql_priv.h:
  Bug#19978: INSERT .. ON DUPLICATE erroneously reports some records were
  updated.
  Added the prototype of the compare_record() function.
mysql-test/t/insert_select.test:
  Added a test case for bug#19978: INSERT .. ON DUPLICATE erroneously reports
  some records were updated.
mysql-test/r/insert_select.result:
  Added a test case for bug#19978: INSERT .. ON DUPLICATE erroneously reports
  some records were updated.

1 files changed, 1 insertions, 1 deletions

diff --git a/sql/sql_update.cc b/sql/sql_update.cc
index b85c617b12d..04d341b5f67 100644
--- a/sql/sql_update.cc
+++ b/sql/sql_update.cc
@@ -26,7 +26,7 @@
 
 /* Return 0 if row hasn't changed */
 
-static bool compare_record(TABLE *table, query_id_t query_id)
+bool compare_record(TABLE *table, query_id_t query_id)
 {
   if (table->s->blob_fields + table->s->varchar_fields == 0)
     return cmp_record(table,record[1]);