[tarantool-patches] [PATCH] Proper error handling for fio.mktree

[Maria]

Method fio.mktree used to create given path
unconditionally - without checking whether
it was a directory or something else. This
way led to inappropriate error messages or
even inconsistent behavior. Now we check the
type of a given path.

Closes #4439

Issue:
https://github.com/tarantool/tarantool/issues/4439
Branch:
https://github.com/tarantool/tarantool/tree/eljashm/gh-4439-error-handling-fio.mktree
---
 src/lua/fio.lua       | 8 +++++++-
 test/app/fio.test.lua | 6 ++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/lua/fio.lua b/src/lua/fio.lua
index 321ae8b2d..a3a8ddc10 100644
--- a/src/lua/fio.lua
+++ b/src/lua/fio.lua
@@ -4,6 +4,7 @@ local fio = require('fio')
 local ffi = require('ffi')
 local buffer = require('buffer')
 local fiber = require('fiber')
+local errno = require('errno')
 
 ffi.cdef[[
     int umask(int mask);
@@ -360,14 +361,19 @@ fio.mktree = function(path, mode)
     local current_dir = "/"
     for i, dir in ipairs(dirs) do
         current_dir = fio.pathjoin(current_dir, dir)
-        if not fio.stat(current_dir) then
+        local stat = fio.stat(current_dir)
+        if stat == nil then
             local st, err = fio.mkdir(current_dir, mode)
             if err ~= nil  then
                 return false, string.format("Error creating directory %s: %s",
                     current_dir, tostring(err))
             end
+        elseif not stat:is_dir() then
+            return false, string.format("Error creating directory %s: %s",
+                current_dir, errno.strerror(errno.EEXIST))
         end
     end
+
     return true
 end
 
diff --git a/test/app/fio.test.lua b/test/app/fio.test.lua
index be735e4f3..56c957d8a 100644
--- a/test/app/fio.test.lua
+++ b/test/app/fio.test.lua
@@ -468,3 +468,9 @@ fio.rmtree(1)
 fio.copytree(nil, nil)
 fio.copytree(nil, nil)
 test_run:cmd("clear filter")
+
+--
+-- gh-4439: mktree error handling fix - creation of existing file/directory
+--
+fio.mktree('/dev/null')
+fio.mktree('/dev/null/dir')
-- 
2.20.1 (Apple Git-117)