Problem
- `redir_exec` is obsolete, but it keeps getting used in new tests
because people copy existing tests.
- Disadvantages of `redir_exec`:
- Captures extra junk before the actual error/message that we _want_ to test.
- Does not fail on error, unlike e.g. `command()`.
Solution
- Use new functions like `nvim_exec` and `pcall_err`.
Problems:
- In two places in shada_read_when_writing() memory just was not freed. Both
places were verified to cause test failures.
- Numbered marks got assigned incorrect (off-by-one compared to position in the
array) numbers in replace_numbered_mark.
- It was possible to have non-continuously populated array of numbered marks
which messed up code for merging them.
(Note about tests: marks with additional data are always compared different when
merging, that caused some confusion regarding why test did not work the way
I expected.)
It is otherwise impossible to determine which test failed sanitizer/valgrind
check. test/functional/helpers.lua module return was changed so that tests which
do not provide after_each function to get new check will automatically fail.
- Remove unused variables.
- Do not use helpers.nvim_feed in most cases.
- Do not use helpers.nvim and helpers.nvim_eval at all.
- Add helpers.funcs and helpers.\*meths special tables. Indexing such table
creates functions which call helpers.call or helpers.nvim (and similar) with
first argument equal to table index.
This problem made test64 to crash. Description of the bug: when removing entry
from history when removed entry is not the last one it puts one element to
free_entries list, but ignores free entries starting from last_free_element.
Possible solutions:
1. First working: simply populate free_entries list with entries which are still
free, starting from last_free_element.
2. Better (wastes less CPU): after free_entries list size goes to zero (which is
the initial value) continue using last_free_element.
3. Even better (less memory): note that element from the list is *only* removed
before adding another one. So replace free_entries array with one item.
Also renamed last_free_element to last_free_entry: in any case most of the lines
which mention it were altered.
