setpos(): Set lowercase mark in other buffers (#5753)

Also make setpos("'A", [999, 1, 1, 0]) fail, i.e. return -1 (assuming there is no buffer 999).

Fixes #5713

Background:

`:help setpos()` mentions an argument `"bufnum"` that determines the buffer a mark should be put in.
This argument is respected for uppercase marks, but not for lowercase marks.
This is reasonable (though I personally would like `setpos()` to be able to set marks in other buffers), but the help doesn't mention this anywhere.

It's also strange that attempting to change buffers with `setpos('.', [bufnr('#'), 1, 1, 0])` alerts the user that having a different buffer is an error, while attempting to set a mark with `setpos("'d", [bufnr('#'), 1, 1, 0])` doesn't tell the user that the `"bufnum"` argument is an error.

1 files changed, 64 insertions, 0 deletions

diff --git a/test/functional/eval/setpos_spec.lua b/test/functional/eval/setpos_spec.lua
new file mode 100644
index 0000000000..2e27cd8ac0
--- /dev/null
+++ b/test/functional/eval/setpos_spec.lua
@@ -0,0 +1,64 @@
+local helpers = require('test.functional.helpers')(after_each)
+local setpos = helpers.funcs.setpos
+local getpos = helpers.funcs.getpos
+local insert = helpers.insert
+local clear = helpers.clear
+local execute = helpers.execute
+local eval = helpers.eval
+local eq = helpers.eq
+local exc_exec = helpers.exc_exec
+
+
+describe('setpos() function', function()
+  before_each(function()
+    clear()
+    insert([[
+    First line of text
+    Second line of text
+    Third line of text]])
+    execute('new')
+    insert([[
+    Line of text 1
+    Line of text 2
+    Line of text 3]])
+  end)
+  it('can set the current cursor position', function()
+    setpos(".", {0, 2, 1, 0})
+    eq(getpos("."), {0, 2, 1, 0})
+    setpos(".", {2, 1, 1, 0})
+    eq(getpos("."), {0, 1, 1, 0})
+    -- Ensure get an error attempting to set position to another buffer
+    local ret = exc_exec('call setpos(".", [1, 1, 1, 0])')
+    eq('Vim(call):E474: Invalid argument', ret)
+  end)
+  it('can set lowercase marks in the current buffer', function()
+    setpos("'d", {0, 2, 1, 0})
+    eq(getpos("'d"), {0, 2, 1, 0})
+    execute('undo', 'call setpos("\'d", [2, 3, 1, 0])')
+    eq(getpos("'d"), {0, 3, 1, 0})
+  end)
+  it('can set lowercase marks in other buffers', function()
+    local retval = setpos("'d", {1, 2, 1, 0})
+    eq(0, retval)
+    setpos("'d", {1, 2, 1, 0})
+    eq(getpos("'d"), {0, 0, 0, 0})
+    execute('wincmd w')
+    eq(eval('bufnr("%")'), 1)
+    eq(getpos("'d"), {0, 2, 1, 0})
+  end)
+  it("fails when setting a mark in a buffer that doesn't exist", function()
+    local retval = setpos("'d", {3, 2, 1, 0})
+    eq(-1, retval)
+    eq(getpos("'d"), {0, 0, 0, 0})
+    retval = setpos("'D", {3, 2, 1, 0})
+    eq(-1, retval)
+    eq(getpos("'D"), {0, 0, 0, 0})
+  end)
+  it('can set uppercase marks', function()
+    setpos("'D", {2, 2, 3, 0})
+    eq(getpos("'D"), {2, 2, 3, 0})
+    -- Can set a mark in another buffer
+    setpos("'D", {1, 2, 2, 0})
+    eq(getpos("'D"), {1, 2, 2, 0})
+  end)
+end)