From 3933592338934933adfeb35dca8472bd28838ec8 Mon Sep 17 00:00:00 2001
From: Andrey Mishchenko <mishchea@gmail.com>
Date: Tue, 26 Apr 2022 23:58:25 -0400
Subject: fix: has() should preserve v:shell_error #18280

fixes #18278
---
 src/nvim/eval/funcs.c                  | 3 +++
 test/functional/vimscript/has_spec.lua | 7 +++++++
 2 files changed, 10 insertions(+)

diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index 5d192eb4b3..9170dd113a 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -4278,6 +4278,8 @@ static void f_has(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     "nvim",
   };
 
+  // XXX: eval_has_provider() may shell out :(
+  const int save_shell_error = get_vim_var_nr(VV_SHELL_ERROR);
   bool n = false;
   const char *const name = tv_get_string(&argvars[0]);
   for (size_t i = 0; i < ARRAY_SIZE(has_list); i++) {
@@ -4334,6 +4336,7 @@ static void f_has(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     n = true;
   }
 
+  set_vim_var_nr(VV_SHELL_ERROR, save_shell_error);
   rettv->vval.v_number = n;
 }
 
diff --git a/test/functional/vimscript/has_spec.lua b/test/functional/vimscript/has_spec.lua
index c03fd13e0c..4d9b226434 100644
--- a/test/functional/vimscript/has_spec.lua
+++ b/test/functional/vimscript/has_spec.lua
@@ -68,4 +68,11 @@ describe('has()', function()
       eq(0, funcs.has('wsl'))
     end
   end)
+
+  it('does not change v:shell_error', function()
+    local nvim_prog = helpers.nvim_prog
+    funcs.system({nvim_prog, '-es', '+73cquit'})
+    funcs.has('python3') -- use a call whose implementation shells out
+    eq(73, funcs.eval('v:shell_error'))
+  end)
 end)
-- 
cgit