mysqldump: memory leak and needless allocation in compression dictionaries

190102 17:50:33 [ 86%] innodb.xtradb_compressed_columns_mysqldump w2 [ fail ]
        Test ended at 2019-01-02 17:50:33

CURRENT_TEST: innodb.xtradb_compressed_columns_mysqldump

=================================================================
==8734==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 105 byte(s) in 3 object(s) allocated from:
    #0 0x7f9c0c0f3c50 in malloc (/usr/lib64/libasan.so.4+0xd9c50)
    #1 0x4b31f7 in my_raw_malloc mysys/my_malloc.cc:199
    #2 0x4b332f in my_malloc(unsigned int, unsigned long, int) mysys/my_malloc.cc:81
    #3 0x4b3952 in my_strdup(unsigned int, char const*, int) mysys/my_malloc.cc:295
    #4 0x479f3e in print_optional_create_compression_dictionary client/mysqldump.cc:2999
    #5 0x47ce5b in get_table_structure client/mysqldump.cc:3401
    #6 0x47e658 in dump_table client/mysqldump.cc:4188
    #7 0x482d96 in dump_all_tables_in_db client/mysqldump.cc:5111
    #8 0x48412d in dump_databases client/mysqldump.cc:4951
    #9 0x459220 in main client/mysqldump.cc:6523
    #10 0x7f9c09957d1f in __libc_start_main (/lib64/libc.so.6+0x1ed1f)

    processed_compression_dictionaries->emplace(
        my_strdup(PSI_NOT_INSTRUMENTED, dictionary_name, MYF(0)));