Remove char_u: vim_setenv()

src/nvim/diff.c

@@ -808,7 +808,7 @@ static void diff_file(char_u *tmp_orig, char_u *tmp_new, char_u *tmp_diff)
 
     /* We don't want $DIFF_OPTIONS to get in the way. */
     if (os_getenv("DIFF_OPTIONS")) {
-      vim_setenv((char_u *)"DIFF_OPTIONS", (char_u *)"");
+      vim_setenv("DIFF_OPTIONS", "");
     }
 
     /* Build the diff command and execute it.  Always use -a, binary

src/nvim/eval.c

@@ -1761,7 +1761,7 @@ ex_let_one (
           }
         }
         if (p != NULL) {
-          vim_setenv(name, p);
+          vim_setenv((char *)name, (char *)p);
           if (STRICMP(name, "HOME") == 0)
             init_homedir();
           else if (didset_vim && STRICMP(name, "VIM") == 0)

src/nvim/ex_cmds2.c

@@ -3127,22 +3127,20 @@ void ex_language(exarg_T *eap)
       ++_nl_msg_cat_cntr;
 #endif
       /* Reset $LC_ALL, otherwise it would overrule everything. */
-      vim_setenv((char_u *)"LC_ALL", (char_u *)"");
+      vim_setenv("LC_ALL", "");
 
       if (what != LC_TIME) {
         /* Tell gettext() what to translate to.  It apparently doesn't
          * use the currently effective locale. */
         if (what == LC_ALL) {
-          vim_setenv((char_u *)"LANG", name);
+          vim_setenv("LANG", (char *)name);
 
           /* Clear $LANGUAGE because GNU gettext uses it. */
-          vim_setenv((char_u *)"LANGUAGE", (char_u *)"");
+          vim_setenv("LANGUAGE", "");
         }
         if (what != LC_CTYPE) {
-          char_u      *mname;
+          vim_setenv("LC_MESSAGES", (char *)name);
-          mname = name;
+          set_helplang_default((char *)name);
-          vim_setenv((char_u *)"LC_MESSAGES", mname);
-          set_helplang_default(mname);
         }
       }
 

src/nvim/option.c

@@ -2288,7 +2288,7 @@ void set_init_3(void)
  * When 'helplang' is still at its default value, set it to "lang".
  * Only the first two characters of "lang" are used.
  */
-void set_helplang_default(char_u *lang)
+void set_helplang_default(const char *lang)
 {
   int idx;
 
@@ -3644,11 +3644,11 @@ did_set_string_option (
   else if (varp == &p_hf) {
     /* May compute new values for $VIM and $VIMRUNTIME */
     if (didset_vim) {
-      vim_setenv((char_u *)"VIM", (char_u *)"");
+      vim_setenv("VIM", "");
       didset_vim = FALSE;
     }
     if (didset_vimruntime) {
-      vim_setenv((char_u *)"VIMRUNTIME", (char_u *)"");
+      vim_setenv("VIMRUNTIME", "");
       didset_vimruntime = FALSE;
     }
   }
@@ -7437,7 +7437,7 @@ void vimrc_found(char_u *fname, char_u *envname)
       /* Set $MYVIMRC to the first vimrc file found. */
       p = FullName_save(fname, FALSE);
       if (p != NULL) {
-        vim_setenv(envname, p);
+        vim_setenv((char *)envname, (char *)p);
         xfree(p);
       }
     } else if (dofree)

src/nvim/os/env.c

@@ -528,10 +528,10 @@ char *vim_getenv(const char *name, bool *mustfree)
    */
   if (p != NULL) {
     if (vimruntime) {
-      vim_setenv((char_u *)"VIMRUNTIME", (char_u *)p);
+      vim_setenv("VIMRUNTIME", p);
       didset_vimruntime = true;
     } else {
-      vim_setenv((char_u *)"VIM", (char_u *)p);
+      vim_setenv("VIM", p);
       didset_vim = true;
     }
   }
@@ -664,16 +664,16 @@ char_u * home_replace_save(buf_T *buf, char_u *src) FUNC_ATTR_NONNULL_RET
 /// Our portable version of setenv.
 /// Has special handling for $VIMRUNTIME to keep the localization machinery
 /// sane.
-void vim_setenv(char_u *name, char_u *val)
+void vim_setenv(const char *name, const char *val)
 {
-  os_setenv((char *)name, (char *)val, 1);
+  os_setenv(name, val, 1);
   /*
    * When setting $VIMRUNTIME adjust the directory to find message
    * translations to $VIMRUNTIME/lang.
    */
   if (*val != NUL && STRICMP(name, "VIMRUNTIME") == 0) {
-    char_u  *buf = concat_str(val, (char_u *)"/lang");
+    char *buf = (char *)concat_str((char_u *)val, (char_u *)"/lang");
-    bindtextdomain(VIMPACKAGE, (char *)buf);
+    bindtextdomain(VIMPACKAGE, buf);
     xfree(buf);
   }
 }