patch 8.1.0888: the a: dict is not immutable as documented
Problem: The a: dict is not immutable as documented.
Solution: Make the a:dict immutable, add a test. (Ozaki Kiichi, Yasuhiro
Matsumoto, closes #3929)
diff --git a/src/testdir/test_let.vim b/src/testdir/test_let.vim
index 24c6ef5..550655c 100644
--- a/src/testdir/test_let.vim
+++ b/src/testdir/test_let.vim
@@ -25,3 +25,124 @@
let s = "\na #1\nb #2"
call assert_equal(s, out)
endfunc
+
+func s:set_arg1(a) abort
+ let a:a = 1
+endfunction
+
+func s:set_arg2(a) abort
+ let a:b = 1
+endfunction
+
+func s:set_arg3(a) abort
+ let b = a:
+ let b['a'] = 1
+endfunction
+
+func s:set_arg4(a) abort
+ let b = a:
+ let b['a'] = 1
+endfunction
+
+func s:set_arg5(a) abort
+ let b = a:
+ let b['a'][0] = 1
+endfunction
+
+func s:set_arg6(a) abort
+ let a:a[0] = 1
+endfunction
+
+func s:set_arg7(a) abort
+ call extend(a:, {'a': 1})
+endfunction
+
+func s:set_arg8(a) abort
+ call extend(a:, {'b': 1})
+endfunction
+
+func s:set_arg9(a) abort
+ let a:['b'] = 1
+endfunction
+
+func s:set_arg10(a) abort
+ let b = a:
+ call extend(b, {'a': 1})
+endfunction
+
+func s:set_arg11(a) abort
+ let b = a:
+ call extend(b, {'b': 1})
+endfunction
+
+func s:set_arg12(a) abort
+ let b = a:
+ let b['b'] = 1
+endfunction
+
+func Test_let_arg_fail()
+ call assert_fails('call s:set_arg1(1)', 'E46:')
+ call assert_fails('call s:set_arg2(1)', 'E461:')
+ call assert_fails('call s:set_arg3(1)', 'E46:')
+ call assert_fails('call s:set_arg4(1)', 'E46:')
+ call assert_fails('call s:set_arg5(1)', 'E46:')
+ call s:set_arg6([0])
+ call assert_fails('call s:set_arg7(1)', 'E742:')
+ call assert_fails('call s:set_arg8(1)', 'E742:')
+ call assert_fails('call s:set_arg9(1)', 'E461:')
+ call assert_fails('call s:set_arg10(1)', 'E742:')
+ call assert_fails('call s:set_arg11(1)', 'E742:')
+ call assert_fails('call s:set_arg12(1)', 'E461:')
+endfunction
+
+func s:set_varg1(...) abort
+ let a:000 = []
+endfunction
+
+func s:set_varg2(...) abort
+ let a:000[0] = 1
+endfunction
+
+func s:set_varg3(...) abort
+ let a:000 += [1]
+endfunction
+
+func s:set_varg4(...) abort
+ call add(a:000, 1)
+endfunction
+
+func s:set_varg5(...) abort
+ let a:000[0][0] = 1
+endfunction
+
+func s:set_varg6(...) abort
+ let b = a:000
+ let b[0] = 1
+endfunction
+
+func s:set_varg7(...) abort
+ let b = a:000
+ let b += [1]
+endfunction
+
+func s:set_varg8(...) abort
+ let b = a:000
+ call add(b, 1)
+endfunction
+
+func s:set_varg9(...) abort
+ let b = a:000
+ let b[0][0] = 1
+endfunction
+
+func Test_let_varg_fail()
+ call assert_fails('call s:set_varg1(1)', 'E46:')
+ call assert_fails('call s:set_varg2(1)', 'E742:')
+ call assert_fails('call s:set_varg3(1)', 'E46:')
+ call assert_fails('call s:set_varg4(1)', 'E742:')
+ call s:set_varg5([0])
+ call assert_fails('call s:set_varg6(1)', 'E742:')
+ " call assert_fails('call s:set_varg7(1)', 'E46:')
+ call assert_fails('call s:set_varg8(1)', 'E742:')
+ call s:set_varg9([0])
+endfunction