Revive vim_fname (-> os_file_exists); fix misuse of mch_getperm.

* Move vim_fname from misc1 to os/fs:os_file_exists.
* Add unit tests for os_file_exists.
* Replace misuse of mch_getperm with os_file_exists.

src/ex_cmds.c

@@ -2310,7 +2310,7 @@ check_overwrite (
               || (buf->b_flags & BF_READERR))
              && !p_wa
              && !bt_nofile(buf)
-             && vim_fexists(ffname)) {
+             && os_file_exists(ffname)) {
     if (!eap->forceit && !eap->append) {
 #ifdef UNIX
       /* with UNIX it is possible to open a directory */
@@ -2336,7 +2336,6 @@ check_overwrite (
     if (other && !emsg_silent) {
       char_u      *dir;
       char_u      *p;
-      int r;
       char_u      *swapname;
 
       /* We only try the first entry in 'directory', without checking if
@@ -2358,8 +2357,7 @@ check_overwrite (
       }
       swapname = makeswapname(fname, ffname, curbuf, dir);
       vim_free(dir);
-      r = vim_fexists(swapname);
-      if (r) {
+      if (os_file_exists(swapname)) {
         if (p_confirm || cmdmod.confirm) {
           char_u buff[DIALOG_MSG_SIZE];
 

src/ex_docmd.c

@@ -7424,7 +7424,7 @@ open_exfile (
     return NULL;
   }
 #endif
-  if (!forceit && *mode != 'a' && vim_fexists(fname)) {
+  if (!forceit && *mode != 'a' && os_file_exists(fname)) {
     EMSG2(_("E189: \"%s\" exists (add ! to override)"), fname);
     return NULL;
   }

src/file_search.c

@@ -837,7 +837,7 @@ char_u *vim_findfile(void *search_ctx_arg)
             for (;; ) {
               /* if file exists and we didn't already find it */
               if ((path_with_url(file_path)
-                   || (mch_getperm(file_path) >= 0
+                   || (os_file_exists(file_path)
                        && (search_ctx->ffsc_find_what
                            == FINDFILE_BOTH
                            || ((search_ctx->ffsc_find_what
@@ -1513,7 +1513,7 @@ find_file_in_path_option (
         buf = suffixes;
         for (;; ) {
           if (
-            (mch_getperm(NameBuff) >= 0
+            (os_file_exists(NameBuff)
              && (find_what == FINDFILE_BOTH
                  || ((find_what == FINDFILE_DIR)
                      == mch_isdir(NameBuff))))) {

src/fileio.c

@@ -3324,12 +3324,12 @@ nobackup:
            * delete an existing one, try to use another name.
            * Change one character, just before the extension.
            */
-          if (!p_bk && mch_getperm(backup) >= 0) {
+          if (!p_bk && os_file_exists(backup)) {
             p = backup + STRLEN(backup) - 1 - STRLEN(backup_ext);
             if (p < backup)             /* empty file name ??? */
               p = backup;
             *p = 'z';
-            while (*p > 'a' && mch_getperm(backup) >= 0)
+            while (*p > 'a' && os_file_exists(backup))
               --*p;
             /* They all exist??? Must be something wrong! */
             if (*p == 'a') {
@@ -5497,7 +5497,7 @@ buf_check_timestamp (
     }
 
   } else if ((buf->b_flags & BF_NEW) && !(buf->b_flags & BF_NEW_W)
-             && vim_fexists(buf->b_ffname)) {
+             && os_file_exists(buf->b_ffname)) {
     retval = 1;
     mesg = _("W13: Warning: File \"%s\" has been created after editing started");
     buf->b_flags |= BF_NEW_W;

src/memline.c

@@ -3636,7 +3636,7 @@ findswapname (
    * check below for a 8.3 file name is used.
    */
   if (!(buf->b_p_sn || buf->b_shortname) && buf_fname != NULL
-      && mch_getperm(buf_fname) < 0)
+      && !os_file_exists(buf_fname))
     dummyfd = mch_fopen((char *)buf_fname, "w");
 #endif
 
@@ -3753,7 +3753,7 @@ findswapname (
     /*
      * check if the swapfile already exists
      */
-    if (mch_getperm(fname) < 0) {       /* it does not exist */
+    if (!os_file_exists(fname)) {       /* it does not exist */
 #ifdef HAVE_LSTAT
       struct stat sb;
 
@@ -3961,7 +3961,7 @@ findswapname (
             }
 
             /* If the file was deleted this fname can be used. */
-            if (mch_getperm(fname) < 0)
+            if (!os_file_exists(fname))
               break;
           } else
 #endif

src/misc1.c

@@ -3827,18 +3827,6 @@ void preserve_exit(void)          {
   getout(1);
 }
 
-/*
- * return TRUE if "fname" exists.
- */
-int vim_fexists(char_u *fname)
-{
-  struct stat st;
-
-  if (mch_stat((char *)fname, &st))
-    return FALSE;
-  return TRUE;
-}
-
 /*
  * Check for CTRL-C pressed, but only once in a while.
  * Should be used instead of ui_breakcheck() for functions that check for
@@ -4196,7 +4184,7 @@ unix_expandpath (
           /* remove backslashes for the remaining components only */
           if (*path_end != NUL)
             backslash_halve(buf + len + 1);
-          if (mch_getperm(buf) >= 0) {          /* add existing file */
+          if (os_file_exists(buf)) {          /* add existing file */
 #ifdef MACOS_CONVERT
             size_t precomp_len = STRLEN(buf)+1;
             char_u *precomp_buf =
@@ -4782,7 +4770,7 @@ gen_expand_wildcards (
        * "vim c:/" work. */
       if (flags & EW_NOTFOUND)
         addfile(&ga, t, flags | EW_DIR | EW_FILE);
-      else if (mch_getperm(t) >= 0)
+      else if (os_file_exists(t))
         addfile(&ga, t, flags);
       vim_free(t);
     }
@@ -4884,7 +4872,7 @@ addfile (
   int isdir;
 
   /* if the file/dir doesn't exist, may not add it */
-  if (!(flags & EW_NOTFOUND) && mch_getperm(f) < 0)
+  if (!(flags & EW_NOTFOUND) && !os_file_exists(f))
     return;
 
 #ifdef FNAME_ILLEGAL

src/misc1.h

@@ -81,7 +81,6 @@ void add_pathsep(char_u *p);
 char_u *FullName_save(char_u *fname, int force);
 void prepare_to_exit(void);
 void preserve_exit(void);
-int vim_fexists(char_u *fname);
 void line_breakcheck(void);
 void fast_breakcheck(void);
 int expand_wildcards_eval(char_u **pat, int *num_file, char_u ***file,

src/os/fs.c

@@ -315,3 +315,20 @@ int mch_setperm(const char_u *name, int perm)
     return OK;
   }
 }
+
+/*
+ * return TRUE if "name" exists.
+ */
+int os_file_exists(char_u *name)
+{
+  uv_fs_t request;
+  int result = uv_fs_stat(uv_default_loop(), &request, (const char*) name, NULL);
+  uv_fs_req_cleanup(&request);
+
+  if (result != 0) {
+    return FALSE;
+  } else {
+    return TRUE;
+  }
+}
+

src/os/os.h

@@ -19,5 +19,6 @@ int mch_get_uname(uid_t uid, char *s, size_t len);
 char *mch_get_user_directory(const char *name);
 long mch_getperm(const char_u *name);
 int mch_setperm(const char_u *name, int perm);
+int os_file_exists(char_u *name);
 
 #endif

src/os_unix.c

@@ -3063,7 +3063,7 @@ int flags;                      /* EW_* flags */
    */
   for (j = 0, i = 0; i < *num_file; ++i) {
     /* Require the files to exist.	Helps when using /bin/sh */
-    if (!(flags & EW_NOTFOUND) && mch_getperm((*file)[i]) < 0)
+    if (!(flags & EW_NOTFOUND) && !os_file_exists((*file)[i]))
       continue;
 
     /* check if this entry should be included */

src/quickfix.c

@@ -615,7 +615,7 @@ restofline:
           *regmatch.endp[i] = c;
 
           if (vim_strchr((char_u *)"OPQ", idx) != NULL
-              && mch_getperm(namebuf) == -1)
+              && !os_file_exists(namebuf))
             continue;
         }
         if ((i = (int)fmt_ptr->addr[1]) > 0) {                  /* %n */
@@ -750,7 +750,7 @@ restofline:
       } else if (vim_strchr((char_u *)"OPQ", idx) != NULL)   {
         /* global file names */
         valid = FALSE;
-        if (*namebuf == NUL || mch_getperm(namebuf) >= 0) {
+        if (*namebuf == NUL || os_file_exists(namebuf)) {
           if (*namebuf && idx == 'P')
             currfile = qf_push_dir(namebuf, &file_stack);
           else if (idx == 'Q')
@@ -1131,7 +1131,7 @@ static int qf_get_fnum(char_u *directory, char_u *fname)
        * "leaving directory"-messages we might have missed a
        * directory change.
        */
-      if (mch_getperm(ptr) < 0) {
+      if (!os_file_exists(ptr)) {
         vim_free(ptr);
         directory = qf_guess_filepath(fname);
         if (directory)
@@ -1289,7 +1289,7 @@ static char_u *qf_guess_filepath(char_u *filename)
     /* If concat_fnames failed, just go on. The worst thing that can happen
      * is that we delete the entire stack.
      */
-    if ((fullname != NULL) && (mch_getperm(fullname) >= 0))
+    if (fullname != NULL && os_file_exists(fullname))
       break;
 
     ds_ptr = ds_ptr->next;
@@ -2609,7 +2609,7 @@ static char_u *get_mef_name(void)                     {
     STRCPY(name, p_mef);
     sprintf((char *)name + (p - p_mef), "%d%d", start, off);
     STRCAT(name, p + 2);
-    if (mch_getperm(name) < 0
+    if (!os_file_exists(name)
 #ifdef HAVE_LSTAT
         /* Don't accept a symbolic link, its a security risk. */
         && mch_lstat((char *)name, &sb) < 0

src/tag.c

@@ -2450,7 +2450,7 @@ jumpto_tag (
    * file.  Also accept a file name for which there is a matching BufReadCmd
    * autocommand event (e.g., http://sys/file).
    */
-  if (mch_getperm(fname) < 0
+  if (!os_file_exists(fname)
       && !has_autocmd(EVENT_BUFREADCMD, fname, NULL)
       ) {
     retval = NOTAGFILE;

src/undo.c

@@ -1173,7 +1173,7 @@ void u_write_undo(char_u *name, int forceit, buf_T *buf, char_u *hash)
 
   /* If the undo file already exists, verify that it actually is an undo
    * file, and delete it. */
-  if (mch_getperm(file_name) >= 0) {
+  if (os_file_exists(file_name)) {
     if (name == NULL || !forceit) {
       /* Check we can read it and it's an undo file. */
       fd = mch_open((char *)file_name, O_RDONLY|O_EXTRA, 0);

test/unit/os/fs.moon

@@ -18,6 +18,7 @@ int is_executable(char_u *name);
 int mch_can_exe(char_u *name);
 long mch_getperm(char_u *name);
 int mch_setperm(char_u *name, long perm);
+int os_file_exists(const char_u *name);
 ]]
 
 -- import constants parsed by ffi
@@ -320,3 +321,13 @@ describe 'fs function', ->
       it 'fails if given file does not exist', ->
         perm = ffi.C.kS_IXUSR
         eq FAIL, (mch_setperm 'non-existing-file', perm)
+
+  describe 'os_file_exists', ->
+    os_file_exists = (filename) ->
+      fs.os_file_exists (to_cstr filename)
+
+    it 'returns FALSE when given a non-existing file', ->
+      eq FALSE, (os_file_exists 'non-existing-file')
+
+    it 'returns TRUE when given an existing file', ->
+      eq TRUE, (os_file_exists 'unit-test-directory/test.file')