DirChanged: Publish _after_ updating win/tab CWD.

So getcwd() works correctly during DirChanged event.

Closes #6260

src/nvim/ex_docmd.c

@@ -6943,24 +6943,28 @@ void free_cd_dir(void)
 /// @param scope  Scope of the function call (global, tab or window).
 void post_chdir(CdScope scope)
 {
-  // The local directory of the current window is always overwritten.
+  // Always overwrite the window-local CWD.
   xfree(curwin->w_localdir);
   curwin->w_localdir = NULL;
 
-  // Overwrite the local directory of the current tab page for `cd` and `tcd`
+  // Overwrite the tab-local CWD for :cd, :tcd.
   if (scope >= kCdScopeTab) {
     xfree(curtab->tp_localdir);
     curtab->tp_localdir = NULL;
   }
 
   if (scope < kCdScopeGlobal) {
-    // If still in global directory, need to remember current directory as
-    // global directory.
+    // If still in global directory, set CWD as the global directory.
     if (globaldir == NULL && prev_dir != NULL) {
       globaldir = vim_strsave(prev_dir);
     }
   }
 
+  char curdir[MAXPATHL];
+  if (os_dirname((char_u *)curdir, MAXPATHL) != OK) {
+    EMSG2(_(e_intern2), "post_chdir()");
+    return;
+  }
   switch (scope) {
   case kCdScopeGlobal:
     // We are now in the global directory, no need to remember its name.
@@ -6968,23 +6972,17 @@ void post_chdir(CdScope scope)
     globaldir = NULL;
     break;
   case kCdScopeTab:
-    // Remember this local directory for the tab page.
-    if (os_dirname(NameBuff, MAXPATHL) == OK) {
-      curtab->tp_localdir = vim_strsave(NameBuff);
-    }
+    curtab->tp_localdir = (char_u *)xstrdup(curdir);
     break;
   case kCdScopeWindow:
-    // Remember this local directory for the window.
-    if (os_dirname(NameBuff, MAXPATHL) == OK) {
-      curwin->w_localdir = vim_strsave(NameBuff);
-    }
+    curwin->w_localdir = (char_u *)xstrdup(curdir);
     break;
   case kCdScopeInvalid:
-    // We should never get here
     assert(false);
   }
 
   shorten_fnames(TRUE);
+  do_autocmd_dirchanged(curdir, scope);
 }
 
 /// `:cd`, `:tcd`, `:lcd`, `:chdir`, `:tchdir` and `:lchdir`.

src/nvim/file_search.c

@@ -1519,7 +1519,7 @@ theend:
   return file_name;
 }
 
-static void do_autocmd_dirchanged(char_u *new_dir, CdScope scope)
+void do_autocmd_dirchanged(char *new_dir, CdScope scope)
 {
   static bool recursive = false;
 
@@ -1587,10 +1587,6 @@ int vim_chdir(char_u *new_dir, CdScope scope)
   }
 
   int r = os_chdir((char *)dir_name);
-  if (r == 0) {
-    do_autocmd_dirchanged(dir_name, scope);
-  }
-
   xfree(dir_name);
   return r;
 }

test/functional/autocmd/dirchanged_spec.lua

@@ -20,7 +20,9 @@ describe('autocmd DirChanged', function()
 
   before_each(function()
     clear()
-    command('autocmd DirChanged * let [g:event, g:scope, g:cdcount] = [copy(v:event), expand("<amatch>"), 1 + get(g:, "cdcount", 0)]')
+    command('autocmd DirChanged * let [g:getcwd_rv, g:event, g:amatch, g:cdcount] '
+        ..'  = [getcwd(), copy(v:event), expand("<amatch>"), 1 + get(g:, "cdcount", 0)]'
+        ..[[ | let g:event['cwd'] = substitute(g:event['cwd'], '\\', '/', 'g') ]])
   end)
 
   it('sets v:event', function()
@@ -37,6 +39,17 @@ describe('autocmd DirChanged', function()
     eq(3, eval('g:cdcount'))
   end)
 
+  it('sets getcwd() during event #6260', function()
+    command('lcd '..dirs[1])
+    eq(dirs[1], eval('g:getcwd_rv'))
+
+    command('tcd '..dirs[2])
+    eq(dirs[2], eval('g:getcwd_rv'))
+
+    command('cd '..dirs[3])
+    eq(dirs[3], eval('g:getcwd_rv'))
+  end)
+
   it('disallows recursion', function()
     command('set shellslash')
     -- Set up a _nested_ handler.
@@ -50,13 +63,13 @@ describe('autocmd DirChanged', function()
 
   it('sets <amatch> to CWD "scope"', function()
     command('lcd '..dirs[1])
-    eq('window', eval('g:scope'))
+    eq('window', eval('g:amatch'))
 
     command('tcd '..dirs[2])
-    eq('tab', eval('g:scope'))
+    eq('tab', eval('g:amatch'))
 
     command('cd '..dirs[3])
-    eq('global', eval('g:scope'))
+    eq('global', eval('g:amatch'))
   end)
 
   it('does not trigger if :cd fails', function()