vim-patch:8.0.1708: mkdir with 'p' flag fails on existing directory

Problem:    Mkdir with 'p' flag fails on existing directory, which is
            different from the mkdir shell command.
Solution:   Don't fail if the directory already exists. (James McCoy,
            closes vim/vim#2775)
https://github.com/vim/vim/commit/78a16b0f2a142aae1fdc96c50ab0f25194d0e755

2 files changed, 43 insertions, 23 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index b7ae0d4dc1..d5131e976a 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -12880,33 +12880,36 @@ static void f_mkdir(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   char buf[NUMBUFLEN];
   const char *const dir = tv_get_string_buf(&argvars[0], buf);
   if (*dir == NUL) {
-    rettv->vval.v_number = FAIL;
-  } else {
-    if (*path_tail((char_u *)dir) == NUL) {
-      // Remove trailing slashes.
-      *path_tail_with_sep((char_u *)dir) = NUL;
-    }
+    return;
+  }
 
-    if (argvars[1].v_type != VAR_UNKNOWN) {
-      if (argvars[2].v_type != VAR_UNKNOWN) {
-        prot = tv_get_number_chk(&argvars[2], NULL);
-      }
-      if (prot != -1 && strcmp(tv_get_string(&argvars[1]), "p") == 0) {
-        char *failed_dir;
-        int ret = os_mkdir_recurse(dir, prot, &failed_dir);
-        if (ret != 0) {
-          EMSG3(_(e_mkdir), failed_dir, os_strerror(ret));
-          xfree(failed_dir);
-          rettv->vval.v_number = FAIL;
-          return;
-        } else {
-          rettv->vval.v_number = OK;
-          return;
-        }
+  if (*path_tail((char_u *)dir) == NUL) {
+    // Remove trailing slashes.
+    *path_tail_with_sep((char_u *)dir) = NUL;
+  }
+
+  if (argvars[1].v_type != VAR_UNKNOWN) {
+    if (argvars[2].v_type != VAR_UNKNOWN) {
+      prot = tv_get_number_chk(&argvars[2], NULL);
+      if (prot == -1) {
+        return;
+      }
+    }
+    if (strcmp(tv_get_string(&argvars[1]), "p") == 0) {
+      char *failed_dir;
+      int ret = os_mkdir_recurse(dir, prot, &failed_dir);
+      if (ret != 0) {
+        EMSG3(_(e_mkdir), failed_dir, os_strerror(ret));
+        xfree(failed_dir);
+        rettv->vval.v_number = FAIL;
+        return;
+      } else {
+        rettv->vval.v_number = OK;
+        return;
       }
     }
-    rettv->vval.v_number = prot == -1 ? FAIL : vim_mkdir_emsg(dir, prot);
   }
+  rettv->vval.v_number = vim_mkdir_emsg(dir, prot);
 }
 
 /// "mode()" function
diff --git a/src/nvim/testdir/test_eval_stuff.vim b/src/nvim/testdir/test_eval_stuff.vim
index 111c85bb95..a99b7e9c0b 100644
--- a/src/nvim/testdir/test_eval_stuff.vim
+++ b/src/nvim/testdir/test_eval_stuff.vim
@@ -21,3 +21,20 @@ func Test_E963()
   call assert_fails("let v:oldfiles=''", 'E963:')
   call assert_equal(v_o, v:oldfiles)
 endfunc
+
+func Test_mkdir_p()
+  call mkdir('Xmkdir/nested', 'p')
+  call assert_true(isdirectory('Xmkdir/nested'))
+  try
+    " Trying to make existing directories doesn't error
+    call mkdir('Xmkdir', 'p')
+    call mkdir('Xmkdir/nested', 'p')
+  catch /E739:/
+    call assert_report('mkdir(..., "p") failed for an existing directory')
+  endtry
+  " 'p' doesn't suppress real errors
+  call writefile([], 'Xfile')
+  call assert_fails('call mkdir("Xfile", "p")', 'E739')
+  call delete('Xfile')
+  call delete('Xmkdir', 'rf')
+endfunc