win/env: fix stdpath()/XDG_* initialization, parsing #12829

- Windows environment variables are semicolon-separated, but some logic
  was assuming colon (:). This broke initialization and parsing of
  XDG_CONFIG_DIRS, XDG_DATA_DIRS, 'runtimepath', stdpath(), etc.
- test/defaults_spec: enable tests on Windows

ref #12793

3 files changed, 149 insertions, 129 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 21a5603b93..32830c5d7f 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -7075,7 +7075,7 @@ void get_xdg_var_list(const XDGVarType xdg, typval_T *rettv)
   do {
     size_t dir_len;
     const char *dir;
-    iter = vim_env_iter(':', dirs, iter, &dir, &dir_len);
+    iter = vim_env_iter(ENV_SEPCHAR, dirs, iter, &dir, &dir_len);
     if (dir != NULL && dir_len > 0) {
       char *dir_with_nvim = xmemdupz(dir, dir_len);
       dir_with_nvim = concat_fnames_realloc(dir_with_nvim, "nvim", true);
diff --git a/src/nvim/option.c b/src/nvim/option.c
index a70a634966..8d74cead8d 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -347,22 +347,23 @@ static char *strcpy_comma_escaped(char *dest, const char *src, const size_t len)
   return &dest[len + shift];
 }
 
-/// Compute length of a colon-separated value, doubled and with some suffixes
+/// Compute length of a ENV_SEPCHAR-separated value, doubled and with some
+/// suffixes
 ///
-/// @param[in]  val  Colon-separated array value.
+/// @param[in]  val  ENV_SEPCHAR-separated array value.
 /// @param[in]  common_suf_len  Length of the common suffix which is appended to
 ///                             each item in the array, twice.
 /// @param[in]  single_suf_len  Length of the suffix which is appended to each
 ///                             item in the array once.
 ///
-/// @return Length of the comma-separated string array that contains each item
-///         in the original array twice with suffixes with given length
+/// @return Length of the ENV_SEPCHAR-separated string array that contains each
+///         item in the original array twice with suffixes with given length
 ///         (common_suf is present after each new item, single_suf is present
 ///         after half of the new items) and with commas after each item, commas
 ///         inside the values are escaped.
-static inline size_t compute_double_colon_len(const char *const val,
-                                              const size_t common_suf_len,
-                                              const size_t single_suf_len)
+static inline size_t compute_double_env_sep_len(const char *const val,
+                                                const size_t common_suf_len,
+                                                const size_t single_suf_len)
   FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
 {
   if (val == NULL || *val == NUL) {
@@ -373,7 +374,7 @@ static inline size_t compute_double_colon_len(const char *const val,
   do {
     size_t dir_len;
     const char *dir;
-    iter = vim_env_iter(':', val, iter, &dir, &dir_len);
+    iter = vim_env_iter(ENV_SEPCHAR, val, iter, &dir, &dir_len);
     if (dir != NULL && dir_len > 0) {
       ret += ((dir_len + memcnt(dir, ',', dir_len) + common_suf_len
                + !after_pathsep(dir, dir + dir_len)) * 2
@@ -385,13 +386,13 @@ static inline size_t compute_double_colon_len(const char *const val,
 
 #define NVIM_SIZE (sizeof("nvim") - 1)
 
-/// Add directories to a comma-separated array from a colon-separated one
+/// Add directories to a ENV_SEPCHAR-separated array from a colon-separated one
 ///
 /// Commas are escaped in process. To each item PATHSEP "nvim" is appended in
 /// addition to suf1 and suf2.
 ///
 /// @param[in,out]  dest  Destination comma-separated array.
-/// @param[in]  val  Source colon-separated array.
+/// @param[in]  val  Source ENV_SEPCHAR-separated array.
 /// @param[in]  suf1  If not NULL, suffix appended to destination. Prior to it
 ///                   directory separator is appended. Suffix must not contain
 ///                   commas.
@@ -404,10 +405,10 @@ static inline size_t compute_double_colon_len(const char *const val,
 ///                      Otherwise in reverse.
 ///
 /// @return (dest + appended_characters_length)
-static inline char *add_colon_dirs(char *dest, const char *const val,
-                                   const char *const suf1, const size_t len1,
-                                   const char *const suf2, const size_t len2,
-                                   const bool forward)
+static inline char *add_env_sep_dirs(char *dest, const char *const val,
+                                     const char *const suf1, const size_t len1,
+                                     const char *const suf2, const size_t len2,
+                                     const bool forward)
   FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_RET FUNC_ATTR_NONNULL_ARG(1)
 {
   if (val == NULL || *val == NUL) {
@@ -417,8 +418,8 @@ static inline char *add_colon_dirs(char *dest, const char *const val,
   do {
     size_t dir_len;
     const char *dir;
-    iter = (forward ? vim_env_iter : vim_env_iter_rev)(':', val, iter, &dir,
-                                                       &dir_len);
+    iter = (forward ? vim_env_iter : vim_env_iter_rev)(ENV_SEPCHAR, val, iter,
+                                                       &dir, &dir_len);
     if (dir != NULL && dir_len > 0) {
       dest = strcpy_comma_escaped(dest, dir, dir_len);
       if (!after_pathsep(dest - 1, dest)) {
@@ -581,10 +582,11 @@ static void set_runtimepath_default(bool clean_arg)
       rtp_size += libdir_len + memcnt(libdir, ',', libdir_len) + 1;
     }
   }
-  rtp_size += compute_double_colon_len(data_dirs, NVIM_SIZE + 1 + SITE_SIZE + 1,
-                                       AFTER_SIZE + 1);
-  rtp_size += compute_double_colon_len(config_dirs, NVIM_SIZE + 1,
-                                       AFTER_SIZE + 1);
+  rtp_size += compute_double_env_sep_len(data_dirs,
+                                         NVIM_SIZE + 1 + SITE_SIZE + 1,
+                                         AFTER_SIZE + 1);
+  rtp_size += compute_double_env_sep_len(config_dirs, NVIM_SIZE + 1,
+                                         AFTER_SIZE + 1);
   if (rtp_size == 0) {
     return;
   }
@@ -592,20 +594,20 @@ static void set_runtimepath_default(bool clean_arg)
   char *rtp_cur = rtp;
   rtp_cur = add_dir(rtp_cur, config_home, config_len, kXDGConfigHome,
                     NULL, 0, NULL, 0);
-  rtp_cur = add_colon_dirs(rtp_cur, config_dirs, NULL, 0, NULL, 0, true);
+  rtp_cur = add_env_sep_dirs(rtp_cur, config_dirs, NULL, 0, NULL, 0, true);
   rtp_cur = add_dir(rtp_cur, data_home, data_len, kXDGDataHome,
                     "site", SITE_SIZE, NULL, 0);
-  rtp_cur = add_colon_dirs(rtp_cur, data_dirs, "site", SITE_SIZE, NULL, 0,
-                           true);
+  rtp_cur = add_env_sep_dirs(rtp_cur, data_dirs, "site", SITE_SIZE, NULL, 0,
+                             true);
   rtp_cur = add_dir(rtp_cur, vimruntime, vimruntime_len, kXDGNone,
                     NULL, 0, NULL, 0);
   rtp_cur = add_dir(rtp_cur, libdir, libdir_len, kXDGNone, NULL, 0, NULL, 0);
-  rtp_cur = add_colon_dirs(rtp_cur, data_dirs, "site", SITE_SIZE,
-                           "after", AFTER_SIZE, false);
+  rtp_cur = add_env_sep_dirs(rtp_cur, data_dirs, "site", SITE_SIZE,
+                             "after", AFTER_SIZE, false);
   rtp_cur = add_dir(rtp_cur, data_home, data_len, kXDGDataHome,
                     "site", SITE_SIZE, "after", AFTER_SIZE);
-  rtp_cur = add_colon_dirs(rtp_cur, config_dirs, "after", AFTER_SIZE, NULL, 0,
-                           false);
+  rtp_cur = add_env_sep_dirs(rtp_cur, config_dirs, "after", AFTER_SIZE, NULL, 0,
+                             false);
   rtp_cur = add_dir(rtp_cur, config_home, config_len, kXDGConfigHome,
                     "after", AFTER_SIZE, NULL, 0);
   // Strip trailing comma.
diff --git a/test/functional/options/defaults_spec.lua b/test/functional/options/defaults_spec.lua
index 11ce26410d..92d077ed14 100644
--- a/test/functional/options/defaults_spec.lua
+++ b/test/functional/options/defaults_spec.lua
@@ -290,9 +290,6 @@ describe('XDG-based defaults', function()
     end)
   end)
 
-  -- TODO(jkeyes): tests below fail on win32 because of path separator.
-  if helpers.pending_win32(pending) then return end
-
   local function vimruntime_and_libdir()
     local vimruntime = eval('$VIMRUNTIME')
     -- libdir is hard to calculate reliably across various ci platforms
@@ -301,71 +298,78 @@ describe('XDG-based defaults', function()
     return vimruntime, libdir
   end
 
+  local env_sep = iswin() and ';' or ':'
+  local data_dir = iswin() and 'nvim-data' or 'nvim'
+  local root_path = iswin() and 'C:' or ''
+
   describe('with too long XDG variables', function()
     before_each(function()
       clear({env={
-        XDG_CONFIG_HOME=('/x'):rep(4096),
-        XDG_CONFIG_DIRS=(('/a'):rep(2048)
-                         .. ':' .. ('/b'):rep(2048)
-                         .. (':/c'):rep(512)),
-        XDG_DATA_HOME=('/X'):rep(4096),
-        XDG_DATA_DIRS=(('/A'):rep(2048)
-                       .. ':' .. ('/B'):rep(2048)
-                       .. (':/C'):rep(512)),
+        XDG_CONFIG_HOME=(root_path .. ('/x'):rep(4096)),
+        XDG_CONFIG_DIRS=(root_path .. ('/a'):rep(2048)
+                         .. env_sep.. root_path .. ('/b'):rep(2048)
+                         .. (env_sep .. root_path .. '/c'):rep(512)),
+        XDG_DATA_HOME=(root_path .. ('/X'):rep(4096)),
+        XDG_DATA_DIRS=(root_path .. ('/A'):rep(2048)
+                       .. env_sep .. root_path .. ('/B'):rep(2048)
+                       .. (env_sep .. root_path .. '/C'):rep(512)),
       }})
     end)
 
     it('are correctly set', function()
       local vimruntime, libdir = vimruntime_and_libdir()
 
-      eq((('/x'):rep(4096) .. '/nvim'
-          .. ',' .. ('/a'):rep(2048) .. '/nvim'
-          .. ',' .. ('/b'):rep(2048) .. '/nvim'
-          .. (',' .. '/c/nvim'):rep(512)
-          .. ',' .. ('/X'):rep(4096) .. '/nvim/site'
-          .. ',' .. ('/A'):rep(2048) .. '/nvim/site'
-          .. ',' .. ('/B'):rep(2048) .. '/nvim/site'
-          .. (',' .. '/C/nvim/site'):rep(512)
+      eq(((root_path .. ('/x'):rep(4096) .. '/nvim'
+          .. ',' .. root_path .. ('/a'):rep(2048) .. '/nvim'
+          .. ',' .. root_path .. ('/b'):rep(2048) .. '/nvim'
+          .. (',' .. root_path .. '/c/nvim'):rep(512)
+          .. ',' .. root_path .. ('/X'):rep(4096) .. '/' .. data_dir .. '/site'
+          .. ',' .. root_path .. ('/A'):rep(2048) .. '/nvim/site'
+          .. ',' .. root_path .. ('/B'):rep(2048) .. '/nvim/site'
+          .. (',' .. root_path .. '/C/nvim/site'):rep(512)
           .. ',' .. vimruntime
           .. ',' .. libdir
-          .. (',' .. '/C/nvim/site/after'):rep(512)
-          .. ',' .. ('/B'):rep(2048) .. '/nvim/site/after'
-          .. ',' .. ('/A'):rep(2048) .. '/nvim/site/after'
-          .. ',' .. ('/X'):rep(4096) .. '/nvim/site/after'
-          .. (',' .. '/c/nvim/after'):rep(512)
-          .. ',' .. ('/b'):rep(2048) .. '/nvim/after'
-          .. ',' .. ('/a'):rep(2048) .. '/nvim/after'
-          .. ',' .. ('/x'):rep(4096) .. '/nvim/after'
-      ), meths.get_option('runtimepath'))
+          .. (',' .. root_path .. '/C/nvim/site/after'):rep(512)
+          .. ',' .. root_path .. ('/B'):rep(2048) .. '/nvim/site/after'
+          .. ',' .. root_path .. ('/A'):rep(2048) .. '/nvim/site/after'
+          .. ',' .. root_path .. ('/X'):rep(4096) .. '/' .. data_dir .. '/site/after'
+          .. (',' .. root_path .. '/c/nvim/after'):rep(512)
+          .. ',' .. root_path .. ('/b'):rep(2048) .. '/nvim/after'
+          .. ',' .. root_path .. ('/a'):rep(2048) .. '/nvim/after'
+          .. ',' .. root_path .. ('/x'):rep(4096) .. '/nvim/after'
+      ):gsub('\\', '/')), (meths.get_option('runtimepath')):gsub('\\', '/'))
       meths.command('set runtimepath&')
       meths.command('set backupdir&')
       meths.command('set directory&')
       meths.command('set undodir&')
       meths.command('set viewdir&')
-      eq((('/x'):rep(4096) .. '/nvim'
-          .. ',' .. ('/a'):rep(2048) .. '/nvim'
-          .. ',' .. ('/b'):rep(2048) .. '/nvim'
-          .. (',' .. '/c/nvim'):rep(512)
-          .. ',' .. ('/X'):rep(4096) .. '/nvim/site'
-          .. ',' .. ('/A'):rep(2048) .. '/nvim/site'
-          .. ',' .. ('/B'):rep(2048) .. '/nvim/site'
-          .. (',' .. '/C/nvim/site'):rep(512)
+      eq(((root_path .. ('/x'):rep(4096) .. '/nvim'
+          .. ',' .. root_path .. ('/a'):rep(2048) .. '/nvim'
+          .. ',' .. root_path .. ('/b'):rep(2048) .. '/nvim'
+          .. (',' .. root_path .. '/c/nvim'):rep(512)
+          .. ',' .. root_path .. ('/X'):rep(4096) .. '/' .. data_dir .. '/site'
+          .. ',' .. root_path .. ('/A'):rep(2048) .. '/nvim/site'
+          .. ',' .. root_path .. ('/B'):rep(2048) .. '/nvim/site'
+          .. (',' .. root_path .. '/C/nvim/site'):rep(512)
           .. ',' .. vimruntime
           .. ',' .. libdir
-          .. (',' .. '/C/nvim/site/after'):rep(512)
-          .. ',' .. ('/B'):rep(2048) .. '/nvim/site/after'
-          .. ',' .. ('/A'):rep(2048) .. '/nvim/site/after'
-          .. ',' .. ('/X'):rep(4096) .. '/nvim/site/after'
-          .. (',' .. '/c/nvim/after'):rep(512)
-          .. ',' .. ('/b'):rep(2048) .. '/nvim/after'
-          .. ',' .. ('/a'):rep(2048) .. '/nvim/after'
-          .. ',' .. ('/x'):rep(4096) .. '/nvim/after'
-      ), meths.get_option('runtimepath'))
-      eq('.,' .. ('/X'):rep(4096) .. '/nvim/backup',
-         meths.get_option('backupdir'))
-      eq(('/X'):rep(4096) .. '/nvim/swap//', meths.get_option('directory'))
-      eq(('/X'):rep(4096) .. '/nvim/undo', meths.get_option('undodir'))
-      eq(('/X'):rep(4096) .. '/nvim/view', meths.get_option('viewdir'))
+          .. (',' .. root_path .. '/C/nvim/site/after'):rep(512)
+          .. ',' .. root_path .. ('/B'):rep(2048) .. '/nvim/site/after'
+          .. ',' .. root_path .. ('/A'):rep(2048) .. '/nvim/site/after'
+          .. ',' .. root_path .. ('/X'):rep(4096) .. '/' .. data_dir .. '/site/after'
+          .. (',' .. root_path .. '/c/nvim/after'):rep(512)
+          .. ',' .. root_path .. ('/b'):rep(2048) .. '/nvim/after'
+          .. ',' .. root_path .. ('/a'):rep(2048) .. '/nvim/after'
+          .. ',' .. root_path .. ('/x'):rep(4096) .. '/nvim/after'
+      ):gsub('\\', '/')), (meths.get_option('runtimepath')):gsub('\\', '/'))
+      eq('.,' .. root_path .. ('/X'):rep(4096).. '/' .. data_dir .. '/backup',
+         (meths.get_option('backupdir'):gsub('\\', '/')))
+      eq(root_path .. ('/X'):rep(4096) .. '/' .. data_dir .. '/swap//',
+         (meths.get_option('directory')):gsub('\\', '/'))
+      eq(root_path .. ('/X'):rep(4096) .. '/' .. data_dir .. '/undo',
+         (meths.get_option('undodir')):gsub('\\', '/'))
+      eq(root_path .. ('/X'):rep(4096) .. '/'  ..  data_dir .. '/view',
+         (meths.get_option('viewdir')):gsub('\\', '/'))
     end)
   end)
 
@@ -381,53 +385,61 @@ describe('XDG-based defaults', function()
 
     it('are not expanded', function()
       local vimruntime, libdir = vimruntime_and_libdir()
-      eq(('$XDG_DATA_HOME/nvim'
+      eq((('$XDG_DATA_HOME/nvim'
           .. ',$XDG_DATA_DIRS/nvim'
-          .. ',$XDG_CONFIG_HOME/nvim/site'
+          .. ',$XDG_CONFIG_HOME/' .. data_dir .. '/site'
           .. ',$XDG_CONFIG_DIRS/nvim/site'
           .. ',' .. vimruntime
           .. ',' .. libdir
           .. ',$XDG_CONFIG_DIRS/nvim/site/after'
-          .. ',$XDG_CONFIG_HOME/nvim/site/after'
+          .. ',$XDG_CONFIG_HOME/' .. data_dir .. '/site/after'
           .. ',$XDG_DATA_DIRS/nvim/after'
           .. ',$XDG_DATA_HOME/nvim/after'
-      ), meths.get_option('runtimepath'))
+      ):gsub('\\', '/')), (meths.get_option('runtimepath')):gsub('\\', '/'))
       meths.command('set runtimepath&')
       meths.command('set backupdir&')
       meths.command('set directory&')
       meths.command('set undodir&')
       meths.command('set viewdir&')
-      eq(('$XDG_DATA_HOME/nvim'
+      eq((('$XDG_DATA_HOME/nvim'
           .. ',$XDG_DATA_DIRS/nvim'
-          .. ',$XDG_CONFIG_HOME/nvim/site'
+          .. ',$XDG_CONFIG_HOME/' .. data_dir .. '/site'
           .. ',$XDG_CONFIG_DIRS/nvim/site'
           .. ',' .. vimruntime
           .. ',' .. libdir
           .. ',$XDG_CONFIG_DIRS/nvim/site/after'
-          .. ',$XDG_CONFIG_HOME/nvim/site/after'
+          .. ',$XDG_CONFIG_HOME/' .. data_dir .. '/site/after'
           .. ',$XDG_DATA_DIRS/nvim/after'
           .. ',$XDG_DATA_HOME/nvim/after'
-      ), meths.get_option('runtimepath'))
-      eq('.,$XDG_CONFIG_HOME/nvim/backup', meths.get_option('backupdir'))
-      eq('$XDG_CONFIG_HOME/nvim/swap//', meths.get_option('directory'))
-      eq('$XDG_CONFIG_HOME/nvim/undo', meths.get_option('undodir'))
-      eq('$XDG_CONFIG_HOME/nvim/view', meths.get_option('viewdir'))
+      ):gsub('\\', '/')), (meths.get_option('runtimepath')):gsub('\\', '/'))
+      eq(('.,$XDG_CONFIG_HOME/' .. data_dir .. '/backup'),
+          meths.get_option('backupdir'):gsub('\\', '/'))
+      eq(('$XDG_CONFIG_HOME/' .. data_dir .. '/swap//'),
+          meths.get_option('directory'):gsub('\\', '/'))
+      eq(('$XDG_CONFIG_HOME/' .. data_dir .. '/undo'),
+          meths.get_option('undodir'):gsub('\\', '/'))
+      eq(('$XDG_CONFIG_HOME/' .. data_dir .. '/view'),
+          meths.get_option('viewdir'):gsub('\\', '/'))
       meths.command('set all&')
       eq(('$XDG_DATA_HOME/nvim'
           .. ',$XDG_DATA_DIRS/nvim'
-          .. ',$XDG_CONFIG_HOME/nvim/site'
+          .. ',$XDG_CONFIG_HOME/' .. data_dir .. '/site'
           .. ',$XDG_CONFIG_DIRS/nvim/site'
           .. ',' .. vimruntime
           .. ',' .. libdir
           .. ',$XDG_CONFIG_DIRS/nvim/site/after'
-          .. ',$XDG_CONFIG_HOME/nvim/site/after'
+          .. ',$XDG_CONFIG_HOME/' .. data_dir .. '/site/after'
           .. ',$XDG_DATA_DIRS/nvim/after'
           .. ',$XDG_DATA_HOME/nvim/after'
-      ), meths.get_option('runtimepath'))
-      eq('.,$XDG_CONFIG_HOME/nvim/backup', meths.get_option('backupdir'))
-      eq('$XDG_CONFIG_HOME/nvim/swap//', meths.get_option('directory'))
-      eq('$XDG_CONFIG_HOME/nvim/undo', meths.get_option('undodir'))
-      eq('$XDG_CONFIG_HOME/nvim/view', meths.get_option('viewdir'))
+      ):gsub('\\', '/'), (meths.get_option('runtimepath')):gsub('\\', '/'))
+      eq(('.,$XDG_CONFIG_HOME/' .. data_dir .. '/backup'),
+          meths.get_option('backupdir'):gsub('\\', '/'))
+      eq(('$XDG_CONFIG_HOME/' .. data_dir .. '/swap//'),
+          meths.get_option('directory'):gsub('\\', '/'))
+      eq(('$XDG_CONFIG_HOME/' .. data_dir .. '/undo'),
+          meths.get_option('undodir'):gsub('\\', '/'))
+      eq(('$XDG_CONFIG_HOME/' .. data_dir .. '/view'),
+          meths.get_option('viewdir'):gsub('\\', '/'))
     end)
   end)
 
@@ -435,53 +447,58 @@ describe('XDG-based defaults', function()
     before_each(function()
       clear({env={
         XDG_CONFIG_HOME=', , ,',
-        XDG_CONFIG_DIRS=',-,-,:-,-,-',
+        XDG_CONFIG_DIRS=',-,-,' .. env_sep .. '-,-,-',
         XDG_DATA_HOME=',=,=,',
-        XDG_DATA_DIRS=',≡,≡,:≡,≡,≡',
+        XDG_DATA_DIRS=',≡,≡,' .. env_sep .. '≡,≡,≡',
       }})
     end)
 
     it('are escaped properly', function()
       local vimruntime, libdir = vimruntime_and_libdir()
-      eq(('\\, \\, \\,/nvim'
-          .. ',\\,-\\,-\\,/nvim'
-          .. ',-\\,-\\,-/nvim'
-          .. ',\\,=\\,=\\,/nvim/site'
-          .. ',\\,≡\\,≡\\,/nvim/site'
-          .. ',≡\\,≡\\,≡/nvim/site'
+      local path_sep = iswin() and '\\' or '/'
+      eq(('\\, \\, \\,' .. path_sep .. 'nvim'
+          .. ',\\,-\\,-\\,' .. path_sep .. 'nvim'
+          .. ',-\\,-\\,-' .. path_sep .. 'nvim'
+          .. ',\\,=\\,=\\,' .. path_sep .. data_dir .. path_sep .. 'site'
+          .. ',\\,≡\\,≡\\,' .. path_sep .. 'nvim'  .. path_sep .. 'site'
+          .. ',≡\\,≡\\,≡' .. path_sep .. 'nvim' .. path_sep .. 'site'
           .. ',' .. vimruntime
           .. ',' .. libdir
-          .. ',≡\\,≡\\,≡/nvim/site/after'
-          .. ',\\,≡\\,≡\\,/nvim/site/after'
-          .. ',\\,=\\,=\\,/nvim/site/after'
-          .. ',-\\,-\\,-/nvim/after'
-          .. ',\\,-\\,-\\,/nvim/after'
-          .. ',\\, \\, \\,/nvim/after'
+          .. ',≡\\,≡\\,≡' .. path_sep .. 'nvim' .. path_sep .. 'site' .. path_sep .. 'after'
+          .. ',\\,≡\\,≡\\,' .. path_sep .. 'nvim' .. path_sep .. 'site' .. path_sep .. 'after'
+          .. ',\\,=\\,=\\,'  .. path_sep.. data_dir .. path_sep .. 'site' .. path_sep .. 'after'
+          .. ',-\\,-\\,-' .. path_sep .. 'nvim' .. path_sep .. 'after'
+          .. ',\\,-\\,-\\,' .. path_sep .. 'nvim' .. path_sep .. 'after'
+          .. ',\\, \\, \\,' .. path_sep .. 'nvim' .. path_sep .. 'after'
       ), meths.get_option('runtimepath'))
       meths.command('set runtimepath&')
       meths.command('set backupdir&')
       meths.command('set directory&')
       meths.command('set undodir&')
       meths.command('set viewdir&')
-      eq(('\\, \\, \\,/nvim'
-          .. ',\\,-\\,-\\,/nvim'
-          .. ',-\\,-\\,-/nvim'
-          .. ',\\,=\\,=\\,/nvim/site'
-          .. ',\\,≡\\,≡\\,/nvim/site'
-          .. ',≡\\,≡\\,≡/nvim/site'
+      eq(('\\, \\, \\,' .. path_sep .. 'nvim'
+          .. ',\\,-\\,-\\,' .. path_sep ..'nvim'
+          .. ',-\\,-\\,-' .. path_sep ..'nvim'
+          .. ',\\,=\\,=\\,' .. path_sep ..'' .. data_dir .. '' .. path_sep ..'site'
+          .. ',\\,≡\\,≡\\,' .. path_sep ..'nvim' .. path_sep ..'site'
+          .. ',≡\\,≡\\,≡' .. path_sep ..'nvim' .. path_sep ..'site'
           .. ',' .. vimruntime
           .. ',' .. libdir
-          .. ',≡\\,≡\\,≡/nvim/site/after'
-          .. ',\\,≡\\,≡\\,/nvim/site/after'
-          .. ',\\,=\\,=\\,/nvim/site/after'
-          .. ',-\\,-\\,-/nvim/after'
-          .. ',\\,-\\,-\\,/nvim/after'
-          .. ',\\, \\, \\,/nvim/after'
+          .. ',≡\\,≡\\,≡' .. path_sep ..'nvim' .. path_sep ..'site' .. path_sep ..'after'
+          .. ',\\,≡\\,≡\\,' .. path_sep ..'nvim' .. path_sep ..'site' .. path_sep ..'after'
+          .. ',\\,=\\,=\\,' .. path_sep ..'' .. data_dir .. '' .. path_sep ..'site' .. path_sep ..'after'
+          .. ',-\\,-\\,-' .. path_sep ..'nvim' .. path_sep ..'after'
+          .. ',\\,-\\,-\\,' .. path_sep ..'nvim' .. path_sep ..'after'
+          .. ',\\, \\, \\,' .. path_sep ..'nvim' .. path_sep ..'after'
       ), meths.get_option('runtimepath'))
-      eq('.,\\,=\\,=\\,/nvim/backup', meths.get_option('backupdir'))
-      eq('\\,=\\,=\\,/nvim/swap//', meths.get_option('directory'))
-      eq('\\,=\\,=\\,/nvim/undo', meths.get_option('undodir'))
-      eq('\\,=\\,=\\,/nvim/view', meths.get_option('viewdir'))
+      eq('.,\\,=\\,=\\,' .. path_sep .. data_dir .. '' .. path_sep ..'backup',
+          meths.get_option('backupdir'))
+      eq('\\,=\\,=\\,' .. path_sep ..'' .. data_dir .. '' .. path_sep ..'swap' .. (path_sep):rep(2),
+          meths.get_option('directory'))
+      eq('\\,=\\,=\\,' .. path_sep ..'' .. data_dir .. '' .. path_sep ..'undo',
+          meths.get_option('undodir'))
+      eq('\\,=\\,=\\,' .. path_sep ..'' .. data_dir .. '' .. path_sep ..'view',
+          meths.get_option('viewdir'))
     end)
   end)
 end)
@@ -491,6 +508,7 @@ describe('stdpath()', function()
   -- Windows appends 'nvim-data' instead of just 'nvim' to prevent collisions
   -- due to XDG_CONFIG_HOME and XDG_DATA_HOME being the same.
   local datadir = iswin() and 'nvim-data' or 'nvim'
+  local env_sep = iswin() and ';' or ':'
 
   it('acceptance', function()
     clear()  -- Do not explicitly set any env vars.
@@ -634,13 +652,13 @@ describe('stdpath()', function()
 
     local function set_paths_via_system(var_name, paths)
       local env = base_env()
-      env[var_name] = table.concat(paths, ':')
+      env[var_name] = table.concat(paths, env_sep)
       clear({env=env})
     end
 
     local function set_paths_at_runtime(var_name, paths)
       clear({env=base_env()})
-      meths.set_var('env_val', table.concat(paths, ':'))
+      meths.set_var('env_val', table.concat(paths, env_sep))
       command(('let $%s=g:env_val'):format(var_name))
     end