Remove NUL macro

66 files changed, 2543 insertions, 2544 deletions

diff --git a/src/arabic.c b/src/arabic.c
index 54f88f8757..f62a1a9c05 100644
--- a/src/arabic.c
+++ b/src/arabic.c
@@ -1418,7 +1418,7 @@ int arabic_shape(int c, int *ccp, int *c1p, int prev_c, int prev_c1,
 
   /* Sanity check -- curr_c should, in the future, never be 0.
    * We should, in the future, insert a fatal error here. */
-  if (curr_c == NUL) {
+  if (curr_c == '\0') {
     curr_c = c;
   }
 
@@ -1467,7 +1467,7 @@ int arabic_maycombine(int two)
  */
 static int A_firstc_laa(int c, int c1)
 {
-  if ((c1 != NUL) && (c == a_LAM) && !A_is_harakat(c1)) {
+  if ((c1 != '\0') && (c == a_LAM) && !A_is_harakat(c1)) {
     return c1;
   }
   return 0;
diff --git a/src/ascii.h b/src/ascii.h
index cf488c56a7..e63bdb2fde 100644
--- a/src/ascii.h
+++ b/src/ascii.h
@@ -22,7 +22,6 @@
 #define CharOrdUp(x)    ((x) - 'A')
 #define ROT13(c, a)     (((((c) - (a)) + 13) % 26) + (a))
 
-#define NUL             '\000'
 #define BELL            '\007'
 #define BS              '\010'
 #define TAB             '\011'
diff --git a/src/blowfish.c b/src/blowfish.c
index 67712a2fbc..707d3e53ee 100644
--- a/src/blowfish.c
+++ b/src/blowfish.c
@@ -567,7 +567,7 @@ void bf_crypt_decode(char_u *ptr, long len)
 void bf_crypt_init_keys(char_u *passwd)
 {
   char_u *p;
-  for (p = passwd; *p != NUL; p++) {
+  for (p = passwd; *p != '\0'; p++) {
     BF_CFB_UPDATE(*p);
   }
 }
diff --git a/src/buffer.c b/src/buffer.c
index 8723e31be3..c4455bfe8e 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -747,7 +747,7 @@ do_bufdel (
           break;
       } else {    /* addr_count == 1 */
         arg = skipwhite(arg);
-        if (*arg == NUL)
+        if (*arg == '\0')
           break;
         if (!VIM_ISDIGIT(*arg)) {
           p = skiptowhite_esc(arg);
@@ -1232,7 +1232,7 @@ void enter_buffer(buf_T *buf)
     /* If there is no filetype, allow for detecting one.  Esp. useful for
      * ":ball" used in a autocommand.  If there already is a filetype we
      * might prefer to keep it. */
-    if (*curbuf->b_p_ft == NUL)
+    if (*curbuf->b_p_ft == '\0')
       did_filetype = FALSE;
 
     open_buffer(FALSE, NULL, 0);
@@ -1265,7 +1265,7 @@ void enter_buffer(buf_T *buf)
     (void)keymap_init();
   /* May need to set the spell language.  Can only do this after the buffer
    * has been properly setup. */
-  if (!curbuf->b_help && curwin->w_p_spell && *curwin->w_s->b_p_spl != NUL)
+  if (!curbuf->b_help && curwin->w_p_spell && *curwin->w_s->b_p_spl != '\0')
     (void)did_set_spelllang(curwin);
 
   redraw_later(NOT_VALID);
@@ -1768,7 +1768,7 @@ buflist_findpat (
       for (attempt = 0; attempt <= 3; ++attempt) {
         /* may add '^' and '$' */
         if (toggledollar)
-          *patend = (attempt < 2) ? NUL : '$';           /* add/remove '$' */
+          *patend = (attempt < 2) ? '\0' : '$';           /* add/remove '$' */
         p = pat;
         if (*p == '^' && !(attempt & 1))                 /* add/remove '^' */
           ++p;
@@ -2227,7 +2227,7 @@ setfname (
   struct stat st;
 #endif
 
-  if (ffname == NULL || *ffname == NUL) {
+  if (ffname == NULL || *ffname == '\0') {
     /* Removing the name. */
     vim_free(buf->b_ffname);
     vim_free(buf->b_sfname);
@@ -2443,7 +2443,7 @@ static int otherfile_buf(buf_T *buf, char_u *ffname
 )
 {
   /* no name is different */
-  if (ffname == NULL || *ffname == NUL || buf->b_ffname == NULL)
+  if (ffname == NULL || *ffname == '\0' || buf->b_ffname == NULL)
     return TRUE;
   if (fnamecmp(ffname, buf->b_ffname) == 0)
     return FALSE;
@@ -2653,7 +2653,7 @@ void maketitle(void)
     }
 
     t_str = buf;
-    if (*p_titlestring != NUL) {
+    if (*p_titlestring != '\0') {
       if (stl_syntax & STL_IN_TITLE) {
         int use_sandbox = FALSE;
         int save_called_emsg = called_emsg;
@@ -2714,7 +2714,7 @@ void maketitle(void)
           vim_strncpy(buf + off, (char_u *)_("help"),
               (size_t)(SPACE_FOR_DIR - off - 1));
         else
-          *p = NUL;
+          *p = '\0';
 
         /* Translate unprintable chars and concatenate.  Keep some
          * room for the server name.  When there is no room (very long
@@ -2745,7 +2745,7 @@ void maketitle(void)
 
   if (p_icon) {
     i_str = buf;
-    if (*p_iconstring != NUL) {
+    if (*p_iconstring != '\0') {
       if (stl_syntax & STL_IN_ICON) {
         int use_sandbox = FALSE;
         int save_called_emsg = called_emsg;
@@ -2766,7 +2766,7 @@ void maketitle(void)
         i_name = buf_spname(curbuf);
       else                          /* use file name only in icon */
         i_name = path_tail(curbuf->b_ffname);
-      *i_str = NUL;
+      *i_str = '\0';
       /* Truncate name at 100 bytes. */
       len = (int)STRLEN(i_name);
       if (len > 100) {
@@ -2914,7 +2914,7 @@ build_stl_str_hl (
   /* Get line & check if empty (cursorpos will show "0-1").  Note that
    * p will become invalid when getting another buffer line. */
   p = ml_get_buf(wp->w_buffer, wp->w_cursor.lnum, FALSE);
-  empty_line = (*p == NUL);
+  empty_line = (*p == '\0');
 
   /* Get the byte value now, in case we need it below. This is more
    * efficient than making a copy of the line. */
@@ -2939,22 +2939,22 @@ build_stl_str_hl (
       break;
     }
 
-    if (*s != NUL && *s != '%')
+    if (*s != '\0' && *s != '%')
       prevchar_isflag = prevchar_isitem = FALSE;
 
     /*
      * Handle up to the next '%' or the end.
      */
-    while (*s != NUL && *s != '%' && p + 1 < out + outlen)
+    while (*s != '\0' && *s != '%' && p + 1 < out + outlen)
       *p++ = *s++;
-    if (*s == NUL || p + 1 >= out + outlen)
+    if (*s == '\0' || p + 1 >= out + outlen)
       break;
 
     /*
      * Handle one '%' item.
      */
     s++;
-    if (*s == NUL)      /* ignore trailing % */
+    if (*s == '\0')      /* ignore trailing % */
       break;
     if (*s == '%') {
       if (p + 1 >= out + outlen)
@@ -2984,7 +2984,7 @@ build_stl_str_hl (
       groupdepth--;
 
       t = item[groupitem[groupdepth]].start;
-      *p = NUL;
+      *p = '\0';
       l = vim_strsize(t);
       if (curitem > groupitem[groupdepth] + 1
           && item[groupitem[groupdepth]].minwid == 0) {
@@ -3144,7 +3144,7 @@ build_stl_str_hl (
     case STL_VIM_EXPR:     /* '{' */
       itemisflag = TRUE;
       t = p;
-      while (*s != '}' && *s != NUL && p + 1 < out + outlen)
+      while (*s != '}' && *s != '\0' && p + 1 < out + outlen)
         *p++ = *s++;
       if (*s != '}')            /* missing '}' or out of space */
         break;
@@ -3167,7 +3167,7 @@ build_stl_str_hl (
       do_unlet((char_u *)"g:actual_curbuf", TRUE);
 
       if (str != NULL && *str != 0) {
-        if (*skipdigits(str) == NUL) {
+        if (*skipdigits(str) == '\0') {
           num = atoi((char *)str);
           vim_free(str);
           str = NULL;
@@ -3194,7 +3194,7 @@ build_stl_str_hl (
     case STL_VIRTCOL_ALT:
       /* In list mode virtcol needs to be recomputed */
       virtcol = wp->w_virtcol;
-      if (wp->w_p_list && lcs_tab1 == NUL) {
+      if (wp->w_p_list && lcs_tab1 == '\0') {
         wp->w_p_list = FALSE;
         getvcol(wp, &wp->w_cursor, NULL, &virtcol, NULL);
         wp->w_p_list = TRUE;
@@ -3273,7 +3273,7 @@ build_stl_str_hl (
       break;
 
     case STL_FILETYPE:
-      if (*wp->w_buffer->b_p_ft != NUL
+      if (*wp->w_buffer->b_p_ft != '\0'
           && STRLEN(wp->w_buffer->b_p_ft) < TMPLEN - 3) {
         vim_snprintf((char *)tmp, sizeof(tmp), "[%s]",
             wp->w_buffer->b_p_ft);
@@ -3283,7 +3283,7 @@ build_stl_str_hl (
 
     case STL_FILETYPE_ALT:
       itemisflag = TRUE;
-      if (*wp->w_buffer->b_p_ft != NUL
+      if (*wp->w_buffer->b_p_ft != '\0'
           && STRLEN(wp->w_buffer->b_p_ft) < TMPLEN - 2) {
         vim_snprintf((char *)tmp, sizeof(tmp), ",%s",
             wp->w_buffer->b_p_ft);
@@ -3325,7 +3325,7 @@ build_stl_str_hl (
 
     case STL_HIGHLIGHT:
       t = s;
-      while (*s != '#' && *s != NUL)
+      while (*s != '#' && *s != '\0')
         ++s;
       if (*s == '#') {
         item[curitem].type = Highlight;
@@ -3333,7 +3333,7 @@ build_stl_str_hl (
         item[curitem].minwid = -syn_namen2id(t, (int)(s - t));
         curitem++;
       }
-      if (*s != NUL)
+      if (*s != '\0')
         ++s;
       continue;
     }
@@ -3432,7 +3432,7 @@ build_stl_str_hl (
       prevchar_isflag = FALSE;              /* Item not NULL, but not a flag */
     curitem++;
   }
-  *p = NUL;
+  *p = '\0';
   itemcnt = curitem;
 
   if (usefmt != fmt)
@@ -3497,7 +3497,7 @@ build_stl_str_hl (
       while (++width < maxwidth) {
         s = s + STRLEN(s);
         *s++ = fillchar;
-        *s = NUL;
+        *s = '\0';
       }
 
       --n;              /* count the '<' */
@@ -4131,7 +4131,7 @@ chk_modeline (
   scid_T save_SID;
 
   prev = -1;
-  for (s = ml_get(lnum); *s != NUL; ++s) {
+  for (s = ml_get(lnum); *s != '\0'; ++s) {
     if (prev == -1 || vim_isspace(prev)) {
       if ((prev != -1 && STRNCMP(s, "ex:", (size_t)3) == 0)
           || STRNCMP(s, "vi:", (size_t)3) == 0)
@@ -4174,17 +4174,17 @@ chk_modeline (
     end = FALSE;
     while (end == FALSE) {
       s = skipwhite(s);
-      if (*s == NUL)
+      if (*s == '\0')
         break;
 
       /*
        * Find end of set command: ':' or end of line.
        * Skip over "\:", replacing it with ":".
        */
-      for (e = s; *e != ':' && *e != NUL; ++e)
+      for (e = s; *e != ':' && *e != '\0'; ++e)
         if (e[0] == '\\' && e[1] == ':')
           STRMOVE(e, e + 1);
-      if (*e == NUL)
+      if (*e == '\0')
         end = TRUE;
 
       /*
@@ -4201,9 +4201,9 @@ chk_modeline (
         end = TRUE;
         s = vim_strchr(s, ' ') + 1;
       }
-      *e = NUL;                         /* truncate the set command */
+      *e = '\0';                         /* truncate the set command */
 
-      if (*s != NUL) {                  /* skip over an empty "::" */
+      if (*s != '\0') {                  /* skip over an empty "::" */
         save_SID = current_SID;
         current_SID = SID_MODELINE;
         retval = do_set(s, OPT_MODELINE | OPT_LOCAL | flags);
diff --git a/src/charset.c b/src/charset.c
index 89ce5d38eb..a77a442499 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -169,7 +169,7 @@ int buf_init_chartab(buf_T *buf, int global)
       tilde = FALSE;
       do_isalpha = FALSE;
 
-      if ((*p == '^') && (p[1] != NUL)) {
+      if ((*p == '^') && (p[1] != '\0')) {
         tilde = TRUE;
         ++p;
       }
@@ -183,7 +183,7 @@ int buf_init_chartab(buf_T *buf, int global)
       }
       c2 = -1;
 
-      if ((*p == '-') && (p[1] != NUL)) {
+      if ((*p == '-') && (p[1] != '\0')) {
         ++p;
 
         if (VIM_ISDIGIT(*p)) {
@@ -199,7 +199,7 @@ int buf_init_chartab(buf_T *buf, int global)
           || (c >= 256)
           || ((c2 < c) && (c2 != -1))
           || (c2 >= 256)
-          || !((*p == NUL) || (*p == ','))) {
+          || !((*p == '\0') || (*p == ','))) {
         return FAIL;
       }
 
@@ -271,7 +271,7 @@ int buf_init_chartab(buf_T *buf, int global)
       c = *p;
       p = skip_to_option_part(p);
 
-      if ((c == ',') && (*p == NUL)) {
+      if ((c == ',') && (*p == '\0')) {
         // Trailing comma is not allowed.
         return FAIL;
       }
@@ -344,7 +344,7 @@ char_u *transstr(char_u *s)
     len = 0;
     p = s;
 
-    while (*p != NUL) {
+    while (*p != '\0') {
       if ((l = (*mb_ptr2len)(p)) > 1) {
         c = (*mb_ptr2char)(p);
         p += l;
@@ -371,10 +371,10 @@ char_u *transstr(char_u *s)
     res = alloc((unsigned)(vim_strsize(s) + 1));
   }
 
-  *res = NUL;
+  *res = '\0';
   p = s;
 
-  while (*p != NUL) {
+  while (*p != '\0') {
     if (has_mbyte && ((l = (*mb_ptr2len)(p)) > 1)) {
       c = (*mb_ptr2char)(p);
 
@@ -435,14 +435,14 @@ char_u* str_foldcase(char_u *str, int orglen, char_u *buf, int buflen)
   }
 
   if (buf == NULL) {
-    GA_CHAR(len) = NUL;
+    GA_CHAR(len) = '\0';
   } else {
-    buf[len] = NUL;
+    buf[len] = '\0';
   }
 
   // Make each character lower case.
   i = 0;
-  while (STR_CHAR(i) != NUL) {
+  while (STR_CHAR(i) != '\0') {
     if (enc_utf8 || (has_mbyte && (MB_BYTE2LEN(STR_CHAR(i)) > 1))) {
       if (enc_utf8) {
         int c = utf_ptr2char(STR_PTR(i));
@@ -530,7 +530,7 @@ char_u* transchar(int c)
       || ((c < 256) && vim_isprintc_strict(c))) {
     // printable character
     transchar_buf[i] = c;
-    transchar_buf[i + 1] = NUL;
+    transchar_buf[i + 1] = '\0';
   } else {
     transchar_nonprint(transchar_buf + i, c);
   }
@@ -562,7 +562,7 @@ void transchar_nonprint(char_u *buf, int c)
 {
   if (c == NL) {
     // we use newline in place of a NUL
-    c = NUL;
+    c = '\0';
   } else if ((c == CAR) && (get_fileformat(curbuf) == EOL_MAC)) {
     // we use CR in place of  NL in this case
     c = NL;
@@ -577,14 +577,14 @@ void transchar_nonprint(char_u *buf, int c)
     // DEL displayed as ^?
     buf[1] = c ^ 0x40;
 
-    buf[2] = NUL;
+    buf[2] = '\0';
   } else if (enc_utf8 && (c >= 0x80)) {
     transchar_hex(buf, c);
   } else if ((c >= ' ' + 0x80) && (c <= '~' + 0x80)) {
     // 0xa0 - 0xfe
     buf[0] = '|';
     buf[1] = c - 0x80;
-    buf[2] = NUL;
+    buf[2] = '\0';
   } else {
     // 0x80 - 0x9f and 0xff
     // TODO: EBCDIC I don't know what to do with this chars, so I display
@@ -592,7 +592,7 @@ void transchar_nonprint(char_u *buf, int c)
     buf[0] = '~';
     buf[1] = (c - 0x80) ^ 0x40;
     // 0xff displayed as ~?
-    buf[2] = NUL;
+    buf[2] = '\0';
   }
 }
 
@@ -612,7 +612,7 @@ void transchar_hex(char_u *buf, int c)
   buf[++i] = nr2hex((unsigned)c >> 4);
   buf[++i] = nr2hex((unsigned)c);
   buf[++i] = '>';
-  buf[++i] = NUL;
+  buf[++i] = '\0';
 }
 
 /// Convert the lower 4 bits of byte "c" to its hex character.
@@ -724,7 +724,7 @@ int vim_strnsize(char_u *s, int len)
 {
   assert(s != NULL);
   int size = 0;
-  while (*s != NUL && --len >= 0) {
+  while (*s != '\0' && --len >= 0) {
     if (has_mbyte) {
       int l = (*mb_ptr2len)(s);
       size += ptr2cells(s);
@@ -794,7 +794,7 @@ int linetabsize_col(int startcol, char_u *s)
 {
   colnr_T col = startcol;
 
-  while (*s != NUL) {
+  while (*s != '\0') {
     col += lbr_chartabsize_adv(&s, col);
   }
   return (int)col;
@@ -812,7 +812,7 @@ int win_linetabsize(win_T *wp, char_u *p, colnr_T len)
   colnr_T col = 0;
   char_u *s;
 
-  for (s = p; *s != NUL && (len == MAXCOL || s < p + len); mb_ptr_adv(s)) {
+  for (s = p; *s != '\0' && (len == MAXCOL || s < p + len); mb_ptr_adv(s)) {
     col += win_lbr_chartabsize(wp, s, col, NULL);
   }
   return (int)col;
@@ -901,7 +901,7 @@ int vim_isfilec_or_wc(int c)
 {
   char_u buf[2];
   buf[0] = (char_u)c;
-  buf[1] = NUL;
+  buf[1] = '\0';
   return vim_isfilec(c) || c == ']' || mch_has_wildcard(buf);
 }
 
@@ -946,7 +946,7 @@ int vim_isprintc_strict(int c)
 /// @return The number of characters taken up on the screen.
 int lbr_chartabsize(unsigned char *s, colnr_T col)
 {
-  if (!curwin->w_p_lbr && (*p_sbr == NUL)) {
+  if (!curwin->w_p_lbr && (*p_sbr == '\0')) {
     if (curwin->w_p_wrap) {
       return win_nolbr_chartabsize(curwin, s, col, NULL);
     }
@@ -994,7 +994,7 @@ int win_lbr_chartabsize(win_T *wp, char_u *s, colnr_T col, int *headp)
   int n;
 
   // No 'linebreak' and 'showbreak': return quickly.
-  if (!wp->w_p_lbr && (*p_sbr == NUL)) {
+  if (!wp->w_p_lbr && (*p_sbr == '\0')) {
     if (wp->w_p_wrap) {
       return win_nolbr_chartabsize(wp, s, col, headp);
     }
@@ -1032,7 +1032,7 @@ int win_lbr_chartabsize(win_T *wp, char_u *s, colnr_T col, int *headp)
       mb_ptr_adv(s);
       c = *s;
 
-      if (!((c != NUL)
+      if (!((c != '\0')
             && (vim_isbreak(c)
                 || (!vim_isbreak(c)
                     && ((col2 == col) || !vim_isbreak(*ps)))))) {
@@ -1061,7 +1061,7 @@ int win_lbr_chartabsize(win_T *wp, char_u *s, colnr_T col, int *headp)
   // Set *headp to the size of what we add.
   added = 0;
 
-  if ((*p_sbr != NUL) && wp->w_p_wrap && (col != 0)) {
+  if ((*p_sbr != '\0') && wp->w_p_wrap && (col != 0)) {
     numberextra = win_col_off(wp);
     col += numberextra + mb_added;
 
@@ -1193,15 +1193,15 @@ void getvcol(win_T *wp, pos_T *pos, colnr_T *start, colnr_T *cursor,
   // This function is used very often, do some speed optimizations.
   // When 'list', 'linebreak' and 'showbreak' are not set use a simple loop.
    // Also use this when 'list' is set but tabs take their normal size.
-  if ((!wp->w_p_list || (lcs_tab1 != NUL))
+  if ((!wp->w_p_list || (lcs_tab1 != '\0'))
       && !wp->w_p_lbr
-      && (*p_sbr == NUL)) {
+      && (*p_sbr == '\0')) {
     for (;;) {
       head = 0;
       c = *ptr;
 
       // make sure we don't go past the end of the line
-      if (c == NUL) {
+      if (c == '\0') {
         // NUL at end of line only takes one column
         incr = 1;
         break;
@@ -1250,7 +1250,7 @@ void getvcol(win_T *wp, pos_T *pos, colnr_T *start, colnr_T *cursor,
       incr = win_lbr_chartabsize(wp, ptr, vcol, &head);
 
       // make sure we don't go past the end of the line
-      if (*ptr == NUL) {
+      if (*ptr == '\0') {
         // NUL at end of line only takes one column
         incr = 1;
         break;
@@ -1455,7 +1455,7 @@ char_u* skiphex(char_u *q)
 char_u* skiptodigit(char_u *q)
 {
   char_u *p = q;
-  while (*p != NUL && !VIM_ISDIGIT(*p)) {
+  while (*p != '\0' && !VIM_ISDIGIT(*p)) {
     // skip to next digit
     p++;
   }
@@ -1470,7 +1470,7 @@ char_u* skiptodigit(char_u *q)
 char_u* skiptohex(char_u *q)
 {
   char_u *p = q;
-  while (*p != NUL && !vim_isxdigit(*p)) {
+  while (*p != '\0' && !vim_isxdigit(*p)) {
     // skip to next digit
     p++;
   }
@@ -1654,7 +1654,7 @@ int vim_tolower(int c)
 /// @return Pointer to the next whitespace or NUL character.
 char_u* skiptowhite(char_u *p)
 {
-  while (*p != ' ' && *p != '\t' && *p != NUL) {
+  while (*p != ' ' && *p != '\t' && *p != '\0') {
     p++;
   }
   return p;
@@ -1666,8 +1666,8 @@ char_u* skiptowhite(char_u *p)
 ///
 /// @return Pointer to the next whitespace character.
 char_u* skiptowhite_esc(char_u *p) {
-  while (*p != ' ' && *p != '\t' && *p != NUL) {
-    if (((*p == '\\') || (*p == Ctrl_V)) && (*(p + 1) != NUL)) {
+  while (*p != ' ' && *p != '\t' && *p != '\0') {
+    if (((*p == '\\') || (*p == Ctrl_V)) && (*(p + 1) != '\0')) {
       ++p;
     }
     ++p;
@@ -1705,7 +1705,7 @@ long getdigits(char_u **pp)
 int vim_isblankline(c