diff --git a/mysql-test/r/archive.result b/mysql-test/r/archive.result
index aacaff30898..3ffefd2aedb 100644
--- a/mysql-test/r/archive.result
+++ b/mysql-test/r/archive.result
@@ -12823,3 +12823,22 @@ a	b	c	d	e	f
 -1	b	c	d	e	1
 DROP TABLE t1;
 SET sort_buffer_size=DEFAULT;
+#
+# BUG#11758979 - 51252: ARCHIVE TABLES STILL FAIL UNDER STRESS
+#                TESTS: CRASH, CORRUPTION, 4G MEMOR
+# (to be executed with valgrind)
+CREATE TABLE t1(a BLOB, b VARCHAR(200)) ENGINE=ARCHIVE;
+INSERT INTO t1 VALUES(NULL, '');
+FLUSH TABLE t1;
+# we need this select to workaround BUG#11764364
+SELECT * FROM t1;
+a	b
+NULL	
+CHECKSUM TABLE t1 EXTENDED;
+Table	Checksum
+test.t1	286155052
+FLUSH TABLE t1;
+OPTIMIZE TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	optimize	status	OK
+DROP TABLE t1;
diff --git a/mysql-test/t/archive.test b/mysql-test/t/archive.test
index 4686b3ca1dc..3c18152ccc6 100644
--- a/mysql-test/t/archive.test
+++ b/mysql-test/t/archive.test
@@ -1745,3 +1745,18 @@ INSERT INTO t1 SELECT t1.* FROM t1,t1 t2,t1 t3,t1 t4,t1 t5,t1 t6;
 SELECT * FROM t1 ORDER BY f LIMIT 1;
 DROP TABLE t1;
 SET sort_buffer_size=DEFAULT;
+
+
+--echo #
+--echo # BUG#11758979 - 51252: ARCHIVE TABLES STILL FAIL UNDER STRESS
+--echo #                TESTS: CRASH, CORRUPTION, 4G MEMOR
+--echo # (to be executed with valgrind)
+CREATE TABLE t1(a BLOB, b VARCHAR(200)) ENGINE=ARCHIVE;
+INSERT INTO t1 VALUES(NULL, '');
+FLUSH TABLE t1;
+--echo # we need this select to workaround BUG#11764364
+SELECT * FROM t1;
+CHECKSUM TABLE t1 EXTENDED;
+FLUSH TABLE t1;
+OPTIMIZE TABLE t1;
+DROP TABLE t1;
diff --git a/storage/archive/ha_archive.cc b/storage/archive/ha_archive.cc
index 345c1b6835f..b6947688768 100644
--- a/storage/archive/ha_archive.cc
+++ b/storage/archive/ha_archive.cc
@@ -819,6 +819,7 @@ uint32 ha_archive::max_row_length(const uchar *buf)
        ptr != end ;
        ptr++)
   {
+    if (!table->field[*ptr]->is_null())
       length += 2 + ((Field_blob*)table->field[*ptr])->get_length();
   }
 
@@ -1178,6 +1179,17 @@ int ha_archive::unpack_row(azio_stream *file_to_read, uchar *record)
 
   /* Copy null bits */
   const uchar *ptr= record_buffer->buffer;
+  /*
+    Field::unpack() is not called when field is NULL. For VARCHAR
+    Field::unpack() only unpacks as much bytes as occupied by field
+    value. In these cases respective memory area on record buffer is
+    not initialized.
+
+    These uninitialized areas may be accessed by CHECKSUM TABLE or
+    by optimizer using temporary table (BUG#12997905). We may remove
+    this memset() when they're fixed.
+  */
+  memset(record, 0, table->s->reclength);
   memcpy(record, ptr, table->s->null_bytes);
   ptr+= table->s->null_bytes;
   for (Field **field=table->field ; *field ; field++)