patch 7.4.1847

Problem:    Getting an item from a NULL dict crashes.  Setting a register to a
            NULL list crashes. (Nikolai Pavlov, issue vim#768)  Comparing a NULL
            dict with a NULL dict fails.
Solution:   Properly check for NULL.

patch 7.4.1846

Problem:    Ubsan detects a multiplication overflow.
Solution:   Don't use orig_mouse_time when it's zero. (Dominique Pelle)

patch 7.4.1845

Problem:    Mentioning NetBeans when reading from channel. (Ramel Eshed)
Solution:   Make the text more generic.

patch 7.4.1844

Problem:    Using old function name in comment.  More functions should start
            with test_.
Solution:   Rename function in comment. (Higashi Higashi) Rename
            disable_char_avail_for_testing() to test_disable_char_avail().
            And alloc_fail() to test_alloc_fail().

patch 7.4.1843

Problem:    Tests involving Python are flaky.
Solution:   Set the pt_auto field.  Add tests. (Nikolai Pavlov)

patch 7.4.1842

Problem:    get() works for Partial but not for Funcref.
Solution:   Accept Funcref.  Also return the function itself. (Nikolai Pavlov)

patch 7.4.1841

Problem:    The code to reallocate the buffer used for quickfix is repeated.
Solution:   Move the code to a function. (Yegappan Lakshmanan, closes vim#831)

patch 7.4.1840

Problem:    When using packages an "after" directory cannot be used.
Solution:   Add the "after" directory of the package to 'runtimepath' if it
            exists.

patch 7.4.1839

Problem:    Cannot get the items stored in a partial.
Solution:   Support using get() on a partial.

patch 7.4.1838

Problem:    Functions specifically for testing do not sort together.
Solution:   Rename garbagecollect_for_testing() to test_garbagecollect_now().
            Add test_null_list(), test_null_dict(), etc.