Problem:    Some code not covered by tests.
Solution:   Add a few more tests. (Dominique Pellé, closes #8757)

Problem:    Substitute() accepts a number but not a float expression.
Solution:   Also accept a float. (closes #8331)

Problem:    Some comments are not correct or clear.
Solution:   Adjust the comments.  Add test for cursor position.

Problem:    Failure to compile a pattern not tested much.
Solution:   Add tests where a pattern fails to compile. (Yegappan Lakshmanan,
            closes #7004)

Problem:    Crash when using submatch(0, 1) in substitute().
Solution:   Increment reference count. (closes #6887)

Problem:    Tests do not check the error number properly.0
Solution:   Add a colon after the error number. (closes #6869)

Problem:    assert_fails() checks the last error message.
Solution:   Check the first error, it is more relevant.  Fix all the tests
            that rely on the old behavior.

Problem:    Regexp and other code not tested.
Solution:   Add more tests. (Yegappan Lakshmanan, closes #5904)

Problem:    Channel and sandbox code not sufficiently tested.
Solution:   Add more tests. (Yegappan Lakshmanan, closes #5855)

Problem:    Various functions not properly tested.
Solution:   Add more tests, especially for failures. (Yegappan Lakshmanan,
            closes #5843)

Problem:    Insufficient code coverage for ex_docmd.c functions.
Solution:   Add more tests. (Yegappan Lakshmanan, closes #5618)

Problem:    Missing search/substitute pattern hardly tested.
Solution:   Add test_clear_search_pat() and tests. (Yegappan Lakshmanan,
            closes #5579)

Problem:    Some Ex commands not sufficiently tested.
Solution:   Add more tests. (Yegappan Lakshmanan, closes #5565)

Problem:    Various commands not completely tested.
Solution:   Add more test cases. (Yegappan Lakshmanan, closes #5551)

Problem:    Crash when passing many arguments through a partial. (Andy
            Massimino)
Solution:   Check the number of arguments. (closes #5186)

Problem:    Crash when passing partial to substitute().
Solution:   Take extra arguments into account. (closes #5186)

Problem:    Ml_get error if pattern matches beyond last line.
Solution:   Adjust position if needed. (Christian Brabandt, closes #5139)

Problem:    More functions can be used as methods.
Solution:   Make various functions usable as a method.

Problem:    Mouse double click test is a bit flaky.
Solution:   Add to list of flaky tests.  Update a couple of comments.

Problem:    Buffer left 'nomodifiable' after :substitute. (Ingo Karkat)
Solution:   Save the value of 'modifiable' earlier' (Christian Brabandt,
            closes #4403)

Problem:    Stuck in sandbox with ":s/../\=Function/gn".
Solution:   Don't skip over code to restore sandbox. (Christian Brabandt)

Problem:    Old style tests.
Solution:   Move tests from test14 to new style test files. (Yegappan
            Lakshmanan, closes #4308)

Problem:    When substitute string throws error, substitute happens anyway.
Solution:   Skip substitution when aborting. (closes #4161)

Problem:    Substitute command inssuficiently tested.
Solution:   Add more test coverage. (Dominique Pelle)

Problem:    The 'l' flag in :subsitute is sticky.
Solution:   Reset the flag. (Dominique Pelle, closes #3925)

Problem:    Test files still use function!.
Solution:   Remove the exclamation mark.  Fix overwriting a function.

Problem:    Still too many old style tests.
Solution:   Convert a few more tests to new style. (Yegappan Lakshmanan,
            closes #2256)

Problem:    Test 80 is old style.
Solution:   Turn it into a new style test. (Yegappan Lakshmanan)

Problem:    Invalid memory access when using :sc in Ex mode. (Dominique Pelle)
Solution:   Avoid the column being negative.  Also fix a hang in Ex mode.

Problem:    Flags of :substitute not sufficiently tested.
Solution:   Test up to two letter flag combinations. (James McCoy, closes
            #1479)

Problem:    Several tests are old style.
Solution:   Turn them into new style tests. (Yegappan Lakshmanan)