vim-patch:8.2.0909: cannot go back to the previous local directory

Problem:    Cannot go back to the previous local directory.
Solution:   Add "tcd -" and "lcd -". (Yegappan Lakshmanan, closes vim/vim#4362)
002bc79991

src/nvim/buffer_defs.h

@@ -953,6 +953,7 @@ struct tabpage_S {
   ScopeDictDictItem tp_winvar;      ///< Variable for "t:" Dictionary.
   dict_T *tp_vars;         ///< Internal variables, local to tab page.
   char_u *tp_localdir;     ///< Absolute path of local cwd or NULL.
+  char_u *tp_prevdir;      ///< Previous directory.
 };
 
 /*
@@ -1381,8 +1382,8 @@ struct window_S {
                                     // out of range!)
   int w_arg_idx_invalid;            // editing another file than w_arg_idx
 
-  char_u *w_localdir;          /* absolute path of local directory or
+  char_u *w_localdir;          // absolute path of local directory or NULL
-                                  NULL */
+  char_u *w_prevdir;           // previous directory
   // Options local to a window.
   // They are local because they influence the layout of the window or
   // depend on the window layout.

src/nvim/ex_docmd.c

@@ -7707,6 +7707,21 @@ void free_cd_dir(void)
 
 #endif
 
+// Get the previous directory for the given chdir scope.
+static char_u *get_prevdir(CdScope scope)
+{
+  switch (scope) {
+  case kCdScopeTab:
+    return curtab->tp_prevdir;
+    break;
+  case kCdScopeWindow:
+    return curwin->w_prevdir;
+    break;
+  default:
+    return prev_dir;
+  }
+}
+
 /// Deal with the side effects of changing the current directory.
 ///
 /// @param scope  Scope of the function call (global, tab or window).
@@ -7721,9 +7736,10 @@ void post_chdir(CdScope scope, bool trigger_dirchanged)
   }
 
   if (scope < kCdScopeGlobal) {
+    char_u *pdir = get_prevdir(scope);
     // If still in global directory, set CWD as the global directory.
-    if (globaldir == NULL && prev_dir != NULL) {
+    if (globaldir == NULL && pdir != NULL) {
-      globaldir = vim_strsave(prev_dir);
+      globaldir = vim_strsave(pdir);
     }
   }
 
@@ -7754,10 +7770,13 @@ void post_chdir(CdScope scope, bool trigger_dirchanged)
 }
 
 /// Change directory function used by :cd/:tcd/:lcd Ex commands and the chdir() function.
+/// @param new_dir  The directory to change to.
+/// @param scope    Scope of the function call (global, tab or window).
 /// @return true if the directory is successfully changed.
 bool changedir_func(char_u *new_dir, CdScope scope)
 {
   char_u *tofree;
+  char_u *pdir = NULL;
   bool retval = false;
 
   if (new_dir == NULL || allbuf_locked()) {
@@ -7766,19 +7785,32 @@ bool changedir_func(char_u *new_dir, CdScope scope)
 
   // ":cd -": Change to previous directory
   if (STRCMP(new_dir, "-") == 0) {
-    if (prev_dir == NULL) {
+    pdir = get_prevdir(scope);
+    if (pdir == NULL) {
       EMSG(_("E186: No previous directory"));
       return false;
     }
-    new_dir = prev_dir;
+    new_dir = pdir;
   }
 
-  // Save current directory for next ":cd -"
+  // Free the previous directory
-  tofree = prev_dir;
+  tofree = get_prevdir(scope);
+
   if (os_dirname(NameBuff, MAXPATHL) == OK) {
-    prev_dir = vim_strsave(NameBuff);
+    pdir = vim_strsave(NameBuff);
   } else {
-    prev_dir = NULL;
+    pdir = NULL;
+  }
+
+  switch (scope) {
+  case kCdScopeTab:
+    curtab->tp_prevdir = pdir;
+    break;
+  case kCdScopeWindow:
+    curwin->w_prevdir = pdir;
+    break;
+  default:
+    prev_dir = pdir;
   }
 
 #if defined(UNIX)
@@ -7790,12 +7822,12 @@ bool changedir_func(char_u *new_dir, CdScope scope)
   }
 #endif
 
-  bool dir_differs = prev_dir == NULL || pathcmp((char *)prev_dir, (char *)new_dir, -1) != 0;
+  if (vim_chdir(new_dir) == 0) {
-  if (dir_differs && vim_chdir(new_dir)) {
+    bool dir_differs = pdir == NULL || pathcmp((char *)pdir, (char *)new_dir, -1) != 0;
-    EMSG(_(e_failed));
-  } else {
     post_chdir(scope, dir_differs);
     retval = true;
+  } else {
+    EMSG(_(e_failed));
   }
   xfree(tofree);
 

src/nvim/file_search.c

@@ -54,6 +54,7 @@
 #include "nvim/eval.h"
 #include "nvim/file_search.h"
 #include "nvim/fileio.h"
+#include "nvim/globals.h"
 #include "nvim/memory.h"
 #include "nvim/message.h"
 #include "nvim/misc1.h"
@@ -1666,11 +1667,12 @@ int vim_chdirfile(char_u *fname, CdCause cause)
     NameBuff[0] = NUL;
   }
 
-  if (cause != kCdCauseOther && pathcmp(dir, (char *)NameBuff, -1) != 0) {
+  if (os_chdir(dir) == 0) {
-    if (os_chdir(dir) != 0) {
+    if (cause != kCdCauseOther && pathcmp(dir, (char *)NameBuff, -1) != 0) {
-      return FAIL;
+      do_autocmd_dirchanged(dir, kCdScopeWindow, cause);
     }
-    do_autocmd_dirchanged(dir, kCdScopeWindow, cause);
+  } else {
+    return FAIL;
   }
 
   return OK;

src/nvim/testdir/test_cd.vim

@@ -43,6 +43,20 @@ func Test_cd_minus()
   call assert_equal(path_dotdot, getcwd())
   cd -
   call assert_equal(path, getcwd())
+
+  " Test for :cd - without a previous directory
+  let lines =<< trim [SCRIPT]
+    call assert_fails('cd -', 'E186:')
+    call assert_fails('call chdir("-")', 'E186:')
+    call writefile(v:errors, 'Xresult')
+    qall!
+  [SCRIPT]
+  call writefile(lines, 'Xscript')
+  if RunVim([], [], '--clean -S Xscript')
+    call assert_equal([], readfile('Xresult'))
+  endif
+  call delete('Xscript')
+  call delete('Xresult')
 endfunc
 
 func Test_cd_with_cpo_chdir()
@@ -115,6 +129,69 @@ func Test_chdir_func()
   call delete('Xdir', 'rf')
 endfunc
 
+" Test for changing to the previous directory '-'
+func Test_prev_dir()
+  let topdir = getcwd()
+  call mkdir('Xdir/a/b/c', 'p')
+
+  " Create a few tabpages and windows with different directories
+  new | only
+  tabnew | new
+  tabnew
+  tabfirst
+  cd Xdir
+  tabnext | wincmd t
+  tcd a
+  wincmd w
+  lcd b
+  tabnext
+  tcd a/b/c
+
+  " Change to the previous directory twice in all the windows.
+  tabfirst
+  cd - | cd -
+  tabnext | wincmd t
+  tcd - | tcd -
+  wincmd w
+  lcd - | lcd -
+  tabnext
+  tcd - | tcd -
+
+  " Check the directory of all the windows
+  tabfirst
+  call assert_equal('Xdir', fnamemodify(getcwd(), ':t'))
+  tabnext | wincmd t
+  call assert_equal('a', fnamemodify(getcwd(), ':t'))
+  wincmd w
+  call assert_equal('b', fnamemodify(getcwd(), ':t'))
+  tabnext
+  call assert_equal('c', fnamemodify(getcwd(), ':t'))
+
+  " Change to the previous directory using chdir()
+  tabfirst
+  call chdir("-") | call chdir("-")
+  tabnext | wincmd t
+  call chdir("-") | call chdir("-")
+  wincmd w
+  call chdir("-") | call chdir("-")
+  tabnext
+  call chdir("-") | call chdir("-")
+
+  " Check the directory of all the windows
+  tabfirst
+  call assert_equal('Xdir', fnamemodify(getcwd(), ':t'))
+  tabnext | wincmd t
+  call assert_equal('a', fnamemodify(getcwd(), ':t'))
+  wincmd w
+  call assert_equal('b', fnamemodify(getcwd(), ':t'))
+  tabnext
+  call assert_equal('c', fnamemodify(getcwd(), ':t'))
+
+  only | tabonly
+  call chdir(topdir)
+  call delete('Xdir', 'rf')
+endfunc
+
 func Test_cd_from_non_existing_dir()
   CheckNotMSWindows
 

src/nvim/window.c

@@ -3733,6 +3733,7 @@ void free_tabpage(tabpage_T *tp)
   }
 
   xfree(tp->tp_localdir);
+  xfree(tp->tp_prevdir);
   xfree(tp);
 }
 
@@ -4771,6 +4772,7 @@ static void win_free(win_T *wp, tabpage_T *tp)
   }
 
   xfree(wp->w_localdir);
+  xfree(wp->w_prevdir);
 
   /* Remove the window from the b_wininfo lists, it may happen that the
    * freed memory is re-used for another window. */