vim-patch:8.2.4860: MS-Windows: always uses current directory for executables

Problem:    MS-Windows: always uses current directory for executables.
Solution:   Check the NoDefaultCurrentDirectoryInExePath environment variable.
            (Yasuhiro Matsumoto, closes vim/vim#10341)

https://github.com/vim/vim/commit/05cf63e9bdca1ac070df3e7d9c6dfc45e68ac916

Omit doc change: override in later doc update.

Co-authored-by: Yasuhiro Matsumoto <mattn.jp@gmail.com>

2 files changed, 29 insertions, 5 deletions

diff --git a/src/nvim/os/fs.c b/src/nvim/os/fs.c
index b681b2f832..d0da37b8e7 100644
--- a/src/nvim/os/fs.c
+++ b/src/nvim/os/fs.c
@@ -17,7 +17,6 @@
 #endif
 
 #include "auto/config.h"
-#include "nvim/errors.h"
 #include "nvim/os/fs.h"
 #include "nvim/os/os_defs.h"
 
@@ -36,6 +35,7 @@
 
 #include "nvim/api/private/helpers.h"
 #include "nvim/ascii_defs.h"
+#include "nvim/errors.h"
 #include "nvim/gettext_defs.h"
 #include "nvim/globals.h"
 #include "nvim/log.h"
@@ -356,10 +356,16 @@ static bool is_executable_in_path(const char *name, char **abspath)
   }
 
 #ifdef MSWIN
-  // Prepend ".;" to $PATH.
-  size_t pathlen = strlen(path_env);
-  char *path = memcpy(xmallocz(pathlen + 2), "." ENV_SEPSTR, 2);
-  memcpy(path + 2, path_env, pathlen);
+  char *path = NULL;
+  if (!os_env_exists("NoDefaultCurrentDirectoryInExePath")) {
+    // Prepend ".;" to $PATH.
+    size_t pathlen = strlen(path_env);
+    path = xmallocz(pathlen + 2);
+    memcpy(path, "." ENV_SEPSTR, 2);
+    memcpy(path + 2, path_env, pathlen);
+  } else {
+    path = xstrdup(path_env);
+  }
 #else
   char *path = xstrdup(path_env);
 #endif
diff --git a/test/old/testdir/test_functions.vim b/test/old/testdir/test_functions.vim
index 29bec72f2b..df4c6b1556 100644
--- a/test/old/testdir/test_functions.vim
+++ b/test/old/testdir/test_functions.vim
@@ -3578,6 +3578,24 @@ func Test_isabsolutepath()
   endif
 endfunc
 
+" Test for exepath()
+func Test_exepath()
+  if has('win32')
+    call assert_notequal(exepath('cmd'), '')
+
+    let oldNoDefaultCurrentDirectoryInExePath = $NoDefaultCurrentDirectoryInExePath
+    call writefile(['@echo off', 'echo Evil'], 'vim-test-evil.bat')
+    let $NoDefaultCurrentDirectoryInExePath = ''
+    call assert_notequal(exepath("vim-test-evil.bat"), '')
+    let $NoDefaultCurrentDirectoryInExePath = '1'
+    call assert_equal(exepath("vim-test-evil.bat"), '')
+    let $NoDefaultCurrentDirectoryInExePath = oldNoDefaultCurrentDirectoryInExePath
+    call delete('vim-test-evil.bat')
+  else
+    call assert_notequal(exepath('sh'), '')
+  endif
+endfunc
+
 " Test for virtcol()
 func Test_virtcol()
   new