vim-patch:8.2.3468: problem with :cd when editing file in non-existent directory

Problem:    Problem with :cd when editing file in non-existent directory. (Yee
            Cheng Chin)
Solution:   Prepend the current directory to get the full path. (closes vim/vim#8903)
https://github.com/vim/vim/commit/c6376c798433bcb9ee38a8664299d11454546950

2 files changed, 30 insertions, 5 deletions

diff --git a/src/nvim/path.c b/src/nvim/path.c
index c28d848683..ffe7fb636f 100644
--- a/src/nvim/path.c
+++ b/src/nvim/path.c
@@ -2245,11 +2245,17 @@ int path_full_dir_name(char *directory, char *buffer, size_t len)
   }
 
   if (os_chdir(directory) != SUCCESS) {
-    // Do not return immediately since we may be in the wrong directory.
-    retval = FAIL;
-  }
-
-  if (retval == FAIL || os_dirname((char_u *)buffer, len) == FAIL) {
+    // Path does not exist (yet).  For a full path fail,
+    // will use the path as-is.  For a relative path use
+    // the current directory and append the file name.
+    if (path_is_absolute((const char_u *)directory)) {
+      // Do not return immediately since we may be in the wrong directory.
+      retval = FAIL;
+    } else {
+      xstrlcpy(buffer, old_dir, len);
+      append_path(buffer, directory, len);
+    }
+  } else if (os_dirname((char_u *)buffer, len) == FAIL) {
     // Do not return immediately since we are in the wrong directory.
     retval = FAIL;
   }
diff --git a/src/nvim/testdir/test_cd.vim b/src/nvim/testdir/test_cd.vim
index 0bba321ee2..0502791c88 100644
--- a/src/nvim/testdir/test_cd.vim
+++ b/src/nvim/testdir/test_cd.vim
@@ -215,3 +215,22 @@ func Test_cd_from_non_existing_dir()
   cd -
   call assert_equal(saveddir, getcwd())
 endfunc
+
+func Test_cd_unknown_dir()
+  call mkdir('Xa')
+  cd Xa
+  call writefile(['text'], 'Xb.txt')
+  edit Xa/Xb.txt
+  let first_buf = bufnr()
+  cd ..
+  edit
+  call assert_equal(first_buf, bufnr())
+  edit Xa/Xb.txt
+  call assert_notequal(first_buf, bufnr())
+
+  bwipe!
+  exe "bwipe! " .. first_buf
+  call delete('Xa', 'rf')
+endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab