fix(runtime): make a copy of runtime_search_path when iterating

This is to prevent concurrent modification, just like save_rtp
in the vim 8 implementation

2 files changed, 18 insertions, 0 deletions

diff --git a/test/functional/core/startup_spec.lua b/test/functional/core/startup_spec.lua
index 41c80ab95c..c0d9bf4539 100644
--- a/test/functional/core/startup_spec.lua
+++ b/test/functional/core/startup_spec.lua
@@ -358,6 +358,12 @@ describe('startup', function()
     pack_clear [[ lua _G.test_loadorder = {} vim.cmd "packadd! superspecial\nruntime! filen.lua" ]]
     eq({'ordinary', 'SuperSpecial', 'FANCY', 'FANCY after', 'SuperSpecial after', 'ordinary after'}, exec_lua [[ return _G.test_loadorder ]])
   end)
+
+  it("handles the correct order with a package that changes packpath", function()
+    pack_clear [[ lua _G.test_loadorder = {} vim.cmd "packadd! funky\nruntime! filen.lua" ]]
+    eq({'ordinary', 'funky!', 'FANCY', 'FANCY after', 'ordinary after'}, exec_lua [[ return _G.test_loadorder ]])
+    eq({'ordinary', 'funky!', 'ordinary after'}, exec_lua [[ return _G.nested_order ]])
+  end)
 end)
 
 describe('sysinit', function()
diff --git a/test/functional/fixtures/pack/foo/opt/funky/filen.lua b/test/functional/fixtures/pack/foo/opt/funky/filen.lua
new file mode 100644
index 0000000000..a33b83c2a7
--- /dev/null
+++ b/test/functional/fixtures/pack/foo/opt/funky/filen.lua
@@ -0,0 +1,12 @@
+table.insert(_G.test_loadorder, "funky!")
+
+if not _G.nesty then
+  _G.nesty = true
+  local save_order = _G.test_loadorder
+  _G.test_loadorder = {}
+  _G.vim.o.pp = "" -- funky!
+  vim.cmd [[runtime! filen.lua ]]
+  _G.nested_order = _G.test_loadorder
+  _G.test_loadorder = save_order
+  _G.nesty = nil
+end