refactor: replace char_u #18429

Work on https://github.com/neovim/neovim/issues/459

55 files changed, 519 insertions, 559 deletions

diff --git a/src/nvim/api/command.c b/src/nvim/api/command.c
index 2b2fb446a0..80a5449d29 100644
--- a/src/nvim/api/command.c
+++ b/src/nvim/api/command.c
@@ -413,7 +413,7 @@ String nvim_cmd(uint64_t channel_id, Dict(cmd) *cmd, Dict(cmd_opts) *opts, Error
 
   // Simply pass the first argument (if it exists) as the arg pointer to `set_cmd_addr_type()`
   // since it only ever checks the first argument.
-  set_cmd_addr_type(&ea, argc > 0 ? (char_u *)args[0] : NULL);
+  set_cmd_addr_type(&ea, argc > 0 ? args[0] : NULL);
 
   if (HAS_KEY(cmd->range)) {
     if (!(ea.argt & EX_RANGE)) {
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index c5881dbc5f..bf3fb04a18 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -2109,7 +2109,7 @@ Dictionary nvim_eval_statusline(String str, Dict(eval_statusline) *opts, Error *
   bool highlights = false;
 
   if (str.size < 2 || memcmp(str.data, "%!", 2)) {
-    const char *const errmsg = check_stl_option((char_u *)str.data);
+    const char *const errmsg = check_stl_option(str.data);
     if (errmsg) {
       api_set_error(err, kErrorTypeValidation, "%s", errmsg);
       return result;
diff --git a/src/nvim/autocmd.c b/src/nvim/autocmd.c
index 69f01afcb6..7301e07a06 100644
--- a/src/nvim/autocmd.c
+++ b/src/nvim/autocmd.c
@@ -174,7 +174,7 @@ static void aupat_show(AutoPat *ap, event_T event, int previous_group)
   }
 
   msg_col = 4;
-  msg_outtrans((char_u *)ap->pat);
+  msg_outtrans(ap->pat);
 
   for (AutoCmd *ac = ap->cmds; ac != NULL; ac = ac->next) {
     // skip removed commands
@@ -195,10 +195,10 @@ static void aupat_show(AutoPat *ap, event_T event, int previous_group)
       size_t msglen = 100;
       char *msg = (char *)xmallocz(msglen);
       snprintf(msg, msglen, "%s [%s]", exec_to_string, ac->desc);
-      msg_outtrans((char_u *)msg);
+      msg_outtrans(msg);
       XFREE_CLEAR(msg);
     } else {
-      msg_outtrans((char_u *)exec_to_string);
+      msg_outtrans(exec_to_string);
     }
     XFREE_CLEAR(exec_to_string);
     if (p_verbose > 0) {
@@ -471,7 +471,7 @@ void augroup_del(char *name, bool stupid_legacy_mode)
       FOR_ALL_AUEVENTS(event) {
         FOR_ALL_AUPATS_IN_EVENT(event, ap) {
           if (ap->group == i && ap->pat != NULL) {
-            give_warning((char_u *)_("W19: Deleting augroup that is still in use"), true);
+            give_warning(_("W19: Deleting augroup that is still in use"), true);
             map_put(String, int)(&map_augroup_name_to_id, cstr_as_string(name), AUGROUP_DELETED);
             augroup_map_del(ap->group, NULL);
             return;
@@ -717,7 +717,7 @@ char *au_event_disable(char *what)
   } else {
     STRCAT(new_ei, what);
   }
-  set_string_option_direct("ei", -1, (char_u *)new_ei, OPT_FREE, SID_NONE);
+  set_string_option_direct("ei", -1, new_ei, OPT_FREE, SID_NONE);
   xfree(new_ei);
 
   return save_ei;
@@ -726,7 +726,7 @@ char *au_event_disable(char *what)
 void au_event_restore(char *old_ei)
 {
   if (old_ei != NULL) {
-    set_string_option_direct("ei", -1, (char_u *)old_ei, OPT_FREE, SID_NONE);
+    set_string_option_direct("ei", -1, old_ei, OPT_FREE, SID_NONE);
     xfree(old_ei);
   }
 }
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 85e34e910d..46adb55746 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -948,7 +948,7 @@ char *do_bufdel(int command, char_u *arg, int addr_count, int start_bnr, int end
   int deleted = 0;                // number of buffers deleted
   char *errormsg = NULL;   // return value
   int bnr;                        // buffer number
-  char_u *p;
+  char *p;
 
   if (addr_count == 0) {
     (void)do_buffer(command, DOBUF_CURRENT, FORWARD, 0, forceit);
@@ -985,13 +985,12 @@ char *do_bufdel(int command, char_u *arg, int addr_count, int start_bnr, int end
           break;
         }
         if (!ascii_isdigit(*arg)) {
-          p = skiptowhite_esc(arg);
-          bnr = buflist_findpat(arg, p, command == DOBUF_WIPE,
-                                false, false);
+          p = (char *)skiptowhite_esc(arg);
+          bnr = buflist_findpat(arg, (char_u *)p, command == DOBUF_WIPE, false, false);
           if (bnr < 0) {                    // failed
             break;
           }
-          arg = p;
+          arg = (char_u *)p;
         } else {
           bnr = getdigits_int(&arg, false, 0);
         }
@@ -1679,8 +1678,8 @@ static inline void buf_init_changedtick(buf_T *const buf)
 /// @return  pointer to the buffer
 buf_T *buflist_new(char_u *ffname_arg, char_u *sfname_arg, linenr_T lnum, int flags)
 {
-  char_u *ffname = ffname_arg;
-  char_u *sfname = sfname_arg;
+  char *ffname = (char *)ffname_arg;
+  char *sfname = (char *)sfname_arg;
   buf_T *buf;
 
   fname_expand(curbuf, &ffname, &sfname);       // will allocate ffname
@@ -1690,11 +1689,9 @@ buf_T *buflist_new(char_u *ffname_arg, char_u *sfname_arg, linenr_T lnum, int fl
   // We can use inode numbers when the file exists.  Works better
   // for hard links.
   FileID file_id;
-  bool file_id_valid = (sfname != NULL
-                        && os_fileid((char *)sfname, &file_id));
+  bool file_id_valid = (sfname != NULL && os_fileid(sfname, &file_id));
   if (ffname != NULL && !(flags & (BLN_DUMMY | BLN_NEW))
-      && (buf = buflist_findname_file_id(ffname, &file_id,
-                                         file_id_valid)) != NULL) {
+      && (buf = buflist_findname_file_id(ffname, &file_id, file_id_valid)) != NULL) {
     xfree(ffname);
     if (lnum != 0) {
       buflist_setfpos(buf, (flags & BLN_NOCURWIN) ? NULL : curwin,
@@ -1749,8 +1746,8 @@ buf_T *buflist_new(char_u *ffname_arg, char_u *sfname_arg, linenr_T lnum, int fl
   }
 
   if (ffname != NULL) {
-    buf->b_ffname = ffname;
-    buf->b_sfname = vim_strsave(sfname);
+    buf->b_ffname = (char_u *)ffname;
+    buf->b_sfname = vim_strsave((char_u *)sfname);
   }
 
   clear_wininfo(buf);
@@ -2045,20 +2042,20 @@ void buflist_getfpos(void)
 /// @return  buffer or NULL if not found
 buf_T *buflist_findname_exp(char_u *fname)
 {
-  char_u *ffname;
+  char *ffname;
   buf_T *buf = NULL;
 
   // First make the name into a full path name
-  ffname = (char_u *)FullName_save((char *)fname,
+  ffname = FullName_save((char *)fname,
 #ifdef UNIX
-                                   // force expansion, get rid of symbolic links
-                                   true
+                         // force expansion, get rid of symbolic links
+                         true
 #else
-                                   false
+                         false
 #endif
-                                   );  // NOLINT(whitespace/parens)
+                         );  // NOLINT(whitespace/parens)
   if (ffname != NULL) {
-    buf = buflist_findname(ffname);
+    buf = buflist_findname((char_u *)ffname);
     xfree(ffname);
   }
   return buf;
@@ -2073,14 +2070,14 @@ buf_T *buflist_findname(char_u *ffname)
 {
   FileID file_id;
   bool file_id_valid = os_fileid((char *)ffname, &file_id);
-  return buflist_findname_file_id(ffname, &file_id, file_id_valid);
+  return buflist_findname_file_id((char *)ffname, &file_id, file_id_valid);
 }
 
 /// Same as buflist_findname(), but pass the FileID structure to avoid
 /// getting it twice for the same file.
 ///
 /// @return  buffer or NULL if not found
-static buf_T *buflist_findname_file_id(char_u *ffname, FileID *file_id, bool file_id_valid)
+static buf_T *buflist_findname_file_id(char *ffname, FileID *file_id, bool file_id_valid)
   FUNC_ATTR_PURE
 {
   // Start at the last buffer, expect to find a match sooner.
@@ -2213,7 +2210,7 @@ int buflist_findpat(const char_u *pattern, const char_u *pattern_end, bool unlis
 
 typedef struct {
   buf_T *buf;
-  char_u *match;
+  char *match;
 } bufmatch_T;
 
 /// Compare functions for qsort() below, that compares b_last_used.
@@ -2236,9 +2233,9 @@ int ExpandBufnames(char_u *pat, int *num_file, char_u ***file, int options)
 {
   int count = 0;
   int round;
-  char_u *p;
+  char *p;
   int attempt;
-  char_u *patc;
+  char *patc;
   bufmatch_T *matches = NULL;
 
   *num_file = 0;                    // return values in case of FAIL
@@ -2254,20 +2251,20 @@ int ExpandBufnames(char_u *pat, int *num_file, char_u ***file, int options)
     STRCPY(patc, "\\(^\\|[\\/]\\)");
     STRCPY(patc + 11, pat + 1);
   } else {
-    patc = pat;
+    patc = (char *)pat;
   }
 
   // attempt == 0: try match with    '\<', match at start of word
   // attempt == 1: try match without '\<', match anywhere
   for (attempt = 0; attempt <= 1; attempt++) {
-    if (attempt > 0 && patc == pat) {
+    if (attempt > 0 && (char_u *)patc == pat) {
       break;            // there was no anchor, no need to try again
     }
 
     regmatch_T regmatch;
-    regmatch.regprog = vim_regcomp((char *)patc + attempt * 11, RE_MAGIC);
+    regmatch.regprog = vim_regcomp(patc + attempt * 11, RE_MAGIC);
     if (regmatch.regprog == NULL) {
-      if (patc != pat) {
+      if ((char_u *)patc != pat) {
         xfree(patc);
       }
       return FAIL;
@@ -2294,16 +2291,16 @@ int ExpandBufnames(char_u *pat, int *num_file, char_u ***file, int options)
             count++;
           } else {
             if (options & WILD_HOME_REPLACE) {
-              p = home_replace_save(buf, p);
+              p = (char *)home_replace_save(buf, (char_u *)p);
             } else {
-              p = vim_strsave(p);
+              p = xstrdup(p);
             }
             if (matches != NULL) {
               matches[count].buf = buf;
               matches[count].match = p;
               count++;
             } else {
-              (*file)[count++] = p;
+              (*file)[count++] = (char_u *)p;
             }
           }
         }
@@ -2325,7 +2322,7 @@ int ExpandBufnames(char_u *pat, int *num_file, char_u ***file, int options)
     }
   }
 
-  if (patc != pat) {
+  if ((char_u *)patc != pat) {
     xfree(patc);
   }
 
@@ -2337,12 +2334,12 @@ int ExpandBufnames(char_u *pat, int *num_file, char_u ***file, int options)
     // if the current buffer is first in the list, place it at the end
     if (matches[0].buf == curbuf) {
       for (int i = 1; i < count; i++) {
-        (*file)[i - 1] = matches[i].match;
+        (*file)[i - 1] = (char_u *)matches[i].match;
       }
-      (*file)[count - 1] = matches[0].match;
+      (*file)[count - 1] = (char_u *)matches[0].match;
     } else {
       for (int i = 0; i < count; i++) {
-        (*file)[i] = matches[i].match;
+        (*file)[i] = (char_u *)matches[i].match;
       }
     }
     xfree(matches);
@@ -2355,12 +2352,12 @@ int ExpandBufnames(char_u *pat, int *num_file, char_u ***file, int options)
 /// Check for a match on the file name for buffer "buf" with regprog "prog".
 ///
 /// @param ignore_case  When true, ignore case. Use 'fic' otherwise.
-static char_u *buflist_match(regmatch_T *rmp, buf_T *buf, bool ignore_case)
+static char *buflist_match(regmatch_T *rmp, buf_T *buf, bool ignore_case)
 {
   // First try the short file name, then the long file name.
-  char_u *match = fname_match(rmp, buf->b_sfname, ignore_case);
+  char *match = fname_match(rmp, (char *)buf->b_sfname, ignore_case);
   if (match == NULL && rmp->regprog != NULL) {
-    match = fname_match(rmp, buf->b_ffname, ignore_case);
+    match = fname_match(rmp, (char *)buf->b_ffname, ignore_case);
   }
   return match;
 }
@@ -2370,20 +2367,20 @@ static char_u *buflist_match(regmatch_T *rmp, buf_T *buf, bool ignore_case)
 /// @param ignore_case  When true, ignore case. Use 'fileignorecase' otherwise.
 ///
 /// @return  "name" when there is a match, NULL when not.
-static char_u *fname_match(regmatch_T *rmp, char_u *name, bool ignore_case)
+static char *fname_match(regmatch_T *rmp, char *name, bool ignore_case)
 {
-  char_u *match = NULL;
-  char_u *p;
+  char *match = NULL;
+  char *p;
 
   if (name != NULL) {
     // Ignore case when 'fileignorecase' or the argument is set.
     rmp->rm_ic = p_fic || ignore_case;
-    if (vim_regexec(rmp, name, (colnr_T)0)) {
+    if (vim_regexec(rmp, (char_u *)name, (colnr_T)0)) {
       match = name;
     } else if (rmp->regprog != NULL) {
       // Replace $(HOME) with '~' and try matching again.
-      p = home_replace_save(NULL, name);
-      if (vim_regexec(rmp, p, (colnr_T)0)) {
+      p = (char *)home_replace_save(NULL, (char_u *)name);
+      if (vim_regexec(rmp, (char_u *)p, (colnr_T)0)) {
         match = name;
       }
       xfree(p);
@@ -2658,7 +2655,7 @@ void buflist_list(exarg_T *eap)
     if (buf_spname(buf) != NULL) {
       STRLCPY(NameBuff, buf_spname(buf), MAXPATHL);
     } else {
-      home_replace(buf, (char_u *)buf->b_fname, NameBuff, MAXPATHL, true);
+      home_replace(buf, buf->b_fname, (char *)NameBuff, MAXPATHL, true);
     }
 
     if (message_filtered(NameBuff)) {
@@ -2688,7 +2685,7 @@ void buflist_list(exarg_T *eap)
     }
 
     // put "line 999" in column 40 or after the file name
-    i = 40 - vim_strsize(IObuff);
+    i = 40 - vim_strsize((char *)IObuff);
     do {
       IObuff[len++] = ' ';
     } while (--i > 0 && len < IOSIZE - 18);
@@ -2699,7 +2696,7 @@ void buflist_list(exarg_T *eap)
                    buf == curbuf ? (int64_t)curwin->w_cursor.lnum : (int64_t)buflist_findlnum(buf));
     }
 
-    msg_outtrans(IObuff);
+    msg_outtrans((char *)IObuff);
     line_breakcheck();
   }
 
@@ -2735,10 +2732,10 @@ int buflist_name_nr(int fnum, char_u **fname, linenr_T *lnum)
 /// @param message  give message when buffer already exists
 ///
 /// @return  FAIL for failure (file name already in use by other buffer) OK otherwise.
-int setfname(buf_T *buf, char_u *ffname_arg, char_u *sfname_arg, bool message)
+int setfname(buf_T *buf, char *ffname_arg, char *sfname_arg, bool message)
 {
-  char_u *ffname = ffname_arg;
-  char_u *sfname = sfname_arg;
+  char *ffname = ffname_arg;
+  char *sfname = sfname_arg;
   buf_T *obuf = NULL;
   FileID file_id;
   bool file_id_valid = false;
@@ -2760,7 +2757,7 @@ int setfname(buf_T *buf, char_u *ffname_arg, char_u *sfname_arg, bool message)
     // If the file name is already used in another buffer:
     // - if the buffer is loaded, fail
     // - if the buffer is not loaded, delete it from the list
-    file_id_valid = os_fileid((char *)ffname, &file_id);
+    file_id_valid = os_fileid(ffname, &file_id);
     if (!(buf->b_flags & BF_DUMMY)) {
       obuf = buflist_findname_file_id(ffname, &file_id, file_id_valid);
     }
@@ -2775,16 +2772,16 @@ int setfname(buf_T *buf, char_u *ffname_arg, char_u *sfname_arg, bool message)
       // delete from the list
       close_buffer(NULL, obuf, DOBUF_WIPE, false, false);
     }
-    sfname = vim_strsave(sfname);
+    sfname = xstrdup(sfname);
 #ifdef USE_FNAME_CASE
-    path_fix_case(sfname);            // set correct case for short file name
+    path_fix_case((char_u *)sfname);            // set correct case for short file name
 #endif
     if (buf->b_sfname != buf->b_ffname) {
       xfree(buf->b_sfname);
     }
     xfree(buf->b_ffname);
-    buf->b_ffname = ffname;
-    buf->b_sfname = sfname;
+    buf->b_ffname = (char_u *)ffname;
+    buf->b_sfname = (char_u *)sfname;
   }
   buf->b_fname = (char *)buf->b_sfname;
   if (!file_id_valid) {
@@ -2814,7 +2811,7 @@ void buf_set_name(int fnum, char_u *name)
     buf->b_sfname = NULL;
     // Allocate ffname and expand into full path.  Also resolves .lnk
     // files on Win32.
-    fname_expand(buf, &buf->b_ffname, &buf->b_sfname);
+    fname_expand(buf, (char **)&buf->b_ffname, (char **)&buf->b_sfname);
     buf->b_fname = (char *)buf->b_sfname;
   }
 }
@@ -2859,16 +2856,16 @@ buf_T *setaltfname(char_u *ffname, char_u *sfname, linenr_T lnum)
 /// @param errmsg  give error message
 char_u *getaltfname(bool errmsg)
 {
-  char_u *fname;
+  char *fname;
   linenr_T dummy;
 
-  if (buflist_name_nr(0, &fname, &dummy) == FAIL) {
+  if (buflist_name_nr(0, (char_u **)&fname, &dummy) == FAIL) {
     if (errmsg) {
       emsg(_(e_noalt));
     }
     return NULL;
   }
-  return fname;
+  return (char_u *)fname;
 }
 
 /// Add a file name to the buflist and return its number.
@@ -2916,7 +2913,7 @@ void buflist_altfpos(win_T *win)
 bool otherfile(char_u *ffname)
   FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ALL
 {
-  return otherfile_buf(curbuf, ffname, NULL, false);
+  return otherfile_buf(curbuf, (char *)ffname, NULL, false);
 }
 
 /// Check that "ffname" is not the same file as the file loaded in "buf".
@@ -2926,7 +2923,7 @@ bool otherfile(char_u *ffname)
 /// @param  ffname         full path name to check
 /// @param  file_id_p      information about the file at "ffname".
 /// @param  file_id_valid  whether a valid "file_id_p" was passed in.
-static bool otherfile_buf(buf_T *buf, char_u *ffname, FileID *file_id_p, bool file_id_valid)
+static bool otherfile_buf(buf_T *buf, char *ffname, FileID *file_id_p, bool file_id_valid)
   FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
 {
   // no name is different
@@ -2941,7 +2938,7 @@ static bool otherfile_buf(buf_T *buf, char_u *ffname, FileID *file_id_p, bool fi
     // If no struct stat given, get it now
     if (file_id_p == NULL) {
       file_id_p = &file_id;
-      file_id_valid = os_fileid((char *)ffname, file_id_p);
+      file_id_valid = os_fileid(ffname, file_id_p);
     }
     if (!file_id_valid) {
       // file_id not valid, assume files are different.
@@ -2995,7 +2992,7 @@ static bool buf_same_file_id(buf_T *buf, FileID *file_id)
 /// @param fullname  when non-zero print full path
 void fileinfo(int fullname, int shorthelp, int dont_truncate)
 {
-  char_u *name;
+  char *name;
   int n;
   char *p;
   char *buffer;
@@ -3015,11 +3012,11 @@ void fileinfo(int fullname, int shorthelp, int dont_truncate)
     STRLCPY(p, buf_spname(curbuf), IOSIZE - (p - buffer));
   } else {
     if (!fullname && curbuf->b_fname != NULL) {
-      name = (char_u *)curbuf->b_fname;
+      name = curbuf->b_fname;
     } else {
-      name = curbuf->b_ffname;
+      name = (char *)curbuf->b_ffname;
     }
-    home_replace(shorthelp ? curbuf : NULL, name, (char_u *)p,
+    home_replace(shorthelp ? curbuf : NULL, name, p,
                  (size_t)(IOSIZE - (p - buffer)), true);
   }
 
@@ -3069,7 +3066,7 @@ void fileinfo(int fullname, int shorthelp, int dont_truncate)
               (int)curwin->w_cursor.col + 1, (int)curwin->w_virtcol + 1);
   }
 
-  (void)append_arg_number(curwin, (char_u *)buffer, IOSIZE, !shortmess(SHM_FILE));
+  (void)append_arg_number(curwin, buffer, IOSIZE, !shortmess(SHM_FILE));
 
   if (dont_truncate) {
     // Temporarily set msg_scroll to avoid the message being truncated.
@@ -3103,14 +3100,14 @@ void col_print(char_u *buf, size_t buflen, int col, int vcol)
   }
 }
 
-static char_u *lasttitle = NULL;
-static char_u *lasticon = NULL;
+static char *lasttitle = NULL;
+static char *lasticon = NULL;
 
 /// Put the title name in the title bar and icon of the window.
 void maketitle(void)
 {
-  char_u *title_str = NULL;
-  char_u *icon_str = NULL;
+  char *title_str = NULL;
+  char *icon_str = NULL;
   int maxlen = 0;
   int len;
   int mustset;
@@ -3145,14 +3142,13 @@ void maketitle(void)
         build_stl_str_hl(curwin, buf, sizeof(buf),
                          (char *)p_titlestring, use_sandbox,
                          0, maxlen, NULL, NULL);
-        title_str = (char_u *)buf;
+        title_str = buf;
         if (called_emsg) {
-          set_string_option_direct("titlestring", -1, (char_u *)"",
-                                   OPT_FREE, SID_ERROR);
+          set_string_option_direct("titlestring", -1, "", OPT_FREE, SID_ERROR);
         }
         called_emsg |= save_called_emsg;
       } else {
-        title_str = p_titlestring;
+        title_str = (char *)p_titlestring;
       }
     } else {
       // Format: "fname + (path) (1 of 2) - VIM".
@@ -3195,7 +3191,7 @@ void maketitle(void)
         // Get path of file, replace home dir with ~.
         *buf_p++ = ' ';
         *buf_p++ = '(';
-        home_replace(curbuf, curbuf->b_ffname, (char_u *)buf_p,
+        home_replace(curbuf, (char *)curbuf->b_ffname, buf_p,
                      (SPACE_FOR_DIR - (size_t)(buf_p - buf)), true);
 #ifdef BACKSLASH_IN_FILENAME
         // Avoid "c:/name" to be reduced to "c".
@@ -3232,18 +3228,17 @@ void maketitle(void)
         *buf_p = NUL;
       }
 
-      append_arg_number(curwin, (char_u *)buf_p,
-                        (int)(SPACE_FOR_ARGNR - (size_t)(buf_p - buf)), false);
+      append_arg_number(curwin, buf_p, (int)(SPACE_FOR_ARGNR - (size_t)(buf_p - buf)), false);
 
       xstrlcat(buf_p, " - NVIM", (sizeof(buf) - (size_t)(buf_p - buf)));
 
       if (maxlen > 0) {
         // Make it shorter by removing a bit in the middle.
-        if (vim_strsize((char_u *)buf) > maxlen) {
+        if (vim_strsize(buf) > maxlen) {
           trunc_string((char_u *)buf, (char_u *)buf, maxlen, sizeof(buf));
         }
       }
-      title_str = (char_u *)buf;
+      title_str = buf;
 #undef SPACE_FOR_FNAME
 #undef SPACE_FOR_DIR
 #undef SPACE_FOR_ARGNR
@@ -3252,7 +3247,7 @@ void maketitle(void)
   mustset = value_change(title_str, &lasttitle);
 
   if (p_icon) {
-    icon_str = (char_u *)buf;
+    icon_str = buf;
     if (*p_iconstring != NUL) {
       if (stl_syntax & STL_IN_ICON) {
         int use_sandbox = false;
@@ -3260,34 +3255,33 @@ void maketitle(void)
 
         use_sandbox = was_set_insecurely(curwin, "iconstring", 0);
         called_emsg = false;
-        build_stl_str_hl(curwin, (char *)icon_str, sizeof(buf),
+        build_stl_str_hl(curwin, icon_str, sizeof(buf),
                          (char *)p_iconstring, use_sandbox,
                          0, 0, NULL, NULL);
         if (called_emsg) {
-          set_string_option_direct("iconstring", -1,
-                                   (char_u *)"", OPT_FREE, SID_ERROR);
+          set_string_option_direct("iconstring", -1, "", OPT_FREE, SID_ERROR);
         }
         called_emsg |= save_called_emsg;
       } else {
-        icon_str = p_iconstring;
+        icon_str = (char *)p_iconstring;
       }
     } else {
-      char_u *buf_p;
+      char *buf_p;
       if (buf_spname(curbuf) != NULL) {
         buf_p = buf_spname(curbuf);
       } else {                        // use file name only in icon
-        buf_p = (char_u *)path_tail((char *)curbuf->b_ffname);
+        buf_p = path_tail((char *)curbuf->b_ffname);
       }
       *icon_str = NUL;
       // Truncat